The finishing of a piece of furniture, a wooden object, is done by applying several coats which are sometimes different. They may have different base (water-based or solvent-based) or resin in the composition (nitro, polyurethane, acrylic, etc). To avoid problems, compatible materials must be used or, if they cannot normally be used together, certain rules must be followed when they are overlaid.
Let's start with colouring. Very often I have been asked if you can apply a water-based basecoat when a solvent-based finish follows and vice versa. I tend to say "yes, why not". Only, this "yes" is always followed by "but...". If the bath is water-based, it must be completely dry before the next solvent-based coat is applied. Otherwise, there is a risk that the varnish will turn white.
photo source: woodworkingtalk.com
In the reverse situation, the solvent-based bath and the following waterborne layer, if the bath is not completely dry, we will see exactly the incompatibility between water and thinner when mixed. The varnish will not settle well, it will "run" off the surface of the wood, creating craters (holes) in the film. Another problem can occur if the colorants used dissolve in both water and certain solvents (alcohol, acetone, glycols) - universal colorants. When the next coat is applied, the dye will migrate into the water diluting the varnish, even if the varnish is dry, and the stains will appear. They say that the stain "bleeds". To avoid surprises, use water-dilutable, not all-purpose stains.
photo source: boero.it
The above examples are for simple stains, which are obtained by diluting the colorant with water or thinner. However, there are also gins that contain various resins for evenness, pore marking or other special effects. In this case you should check the compatibility in the product data sheet, on the label or ask the supplier. Sometimes the resins present in the bath can be a big headache. I've seen in one factory a whole batch of furniture that was bleaching under the varnish. In the end they discovered an incompatibility between the resin in the varnish and the polyurethane finish applied on top.
photo source: revistadinlemn.ro
Compatibility of materials must also be taken into account when priming and varnishing. Generally, finishing systems with the same base resin are used. However, there are situations where different materials are used. For example, a very nice high gloss can be achieved with polyester products. Polyesters, however, have a rather unpleasant odor (styrene in the composition). The amount used can be reduced by finishing with polyester primer and polyurethane gloss varnish. The hardness and high body content will allow a good sanding of the primer, so you get a very good base for the gloss lacquer. It is a system that gets used a lot without any problems.
photo source: furniturefashion.com
You can make all sorts of combinations, the important thing is to follow certain rules:
- do not apply polyurethane varnish over nitrocellulose primer and, in general, do not apply chemically hardening materials over those with normal drying (by evaporation of the thinner).
- if waterborne materials are used in combination with solvent-based materials, they must be thoroughly dried before overcoating.
- Solvent-based primer must be thoroughly sanded before applying water-based varnish, and sanding should be done immediately before applying the varnish, not the day before. Otherwise big adhesion problems occur and the varnish can peel off the primer just like leather.
- No other materials may be applied over the wax. They will have no adhesion.
- linseed oil-based products are not compatible with normal solvent-based products. However, they work very well with synthetic products that use white spirit as a diluent (alkyd paints, impregnants and synthetic exterior varnishes).
If you want to paint on wooden objects it is good to use different materials to avoid color migration problems. For example, you can use a solvent-based primer which, after drying, you can paint with water-based products. Then protect everything with a coat of solvent varnish. In this case, I always recommend acrylic solvent-based varnishes, which do not change the color of the materials over which it is applied and do not yellow over time. And the water-based colors will not migrate into the acrylic lacquer on solvent,
photo source: rokofurniture.co.uk
In conclusion, use compatible materials, do not stack different materials without checking how they behave first. Ask those who sell them what the restrictions are and respect them. This is the only way to avoid problems. And don't assume that if you have misused materials once and nothing happened, you can do it again. You know the pitcher. 🙂
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Hello
I applied 5 coats of pure tung oil to an oak and walnut coffee table (it was made on my own), the finish is super.
What final coating to use for it if I want to move it from the living room to a covered patio for better protection?
Thank you for your advice and I appreciate your work.
Cerceja Gheorghe
Hello.
Don't give her any more, just leave it at that. You should also apply an oil-based varnish and if the table has absorbed enough oil, the varnish may not have any adhesion. The only thing you need to do is re-spray the finish every 6 months if it sits directly outside and can get rain directly on it, or every 1-2 years if it's on a covered patio as you say. The only problem you may have is if the table has been bathed, and the batten used is not UV resistant (not made for outdoors). In this case, if the sun beats directly on the table, the original colour can fade in less than a year and the table will turn grey.
All the best.
Thank you for your reply.
I used only pure tung oil, sanded between coats and waited until the previous coat was completely dry (6 weeks was all it took).
The terrace is covered and will not get rained on.
I will follow your advice
Thank you
And many interesting articles
Hello!
I would need a specialist's opinion for the following question, and you are the perfect person. If I want to change the shade of a piece of chipboard furniture, what type of varnish would be suitable? Special paint for chipboard I have seen is available, but I don't want to completely change the colour and lose the texture of the veneer.
Thank you!
Ana-Maria S.
Hello,
In chipboard there are problems of adhesion to the substrate, so special products must be used. In general, solvent-based materials have better adhesion than water-based materials. With transparent water-based ones the lack of adhesion can be quite unpleasant, the coating simply flaking off like a skin. Special creamy paints for such finishes (such as Annie Sloan) are preferable because there is no need to prepare the substrate beforehand, and if the layer is thin, you don't lose the texture of the veneer.
If you don't want to use chalky paints try solvent-based varnishes from DIY stores or polyurethane or acrylic varnishes from wood and furniture varnish suppliers (or their distributors). Beforehand you will need to degrease the surface (washed with water and detergent and dried very well, or dried with a solvent rag) and gently sand the surface of the chipboard with an abrasive sponge (without ruining the design). Sanding is to increase the adhesion of the varnish.
All the best!
Thank you very much for your answer!
I will take your specialist advice into account.
I really appreciate your work and the fact that you help even the less knowledgeable in making the right choices for their furniture.
Good luck in everything and all the best!
Hello,
I have a question about the filler.
Can you please tell me, how can we tell if the bath applied to a wooden surface is solvent-based or water-based? Thank you,
Hello,
It is very difficult to identify the type of bath on a finished piece of furniture for sale. With plain baths, a trained eye would see on solid wood a deeper absorption, in the case of water-based baths, with the wood pattern showing through and brighter, more vivid colours, or a uniformity of colouring, with the pattern slightly faded and the colours duller. These are simple baths, i.e. a mixture of stain and water or solvent. But some stains also have additions that make these characteristics less obvious. In addition, by the end, other layers appear - smoothing, patination, etc. - which make the effects of the first coat invisible.
The point is that, after drying, the fact that the bath was water or solvent based matters less. The solvent is completely removed by drying and the dye is covered by the primer and varnish layers. A solvent-based dip affects the person applying it, not the furniture user. The smell of solvent that is sometimes smelled on new furniture is from the film-forming materials (varnish, paint, primer), not from the filler.
I hope I have understood your question well and that the answer will be useful to you.
All the best!
Thank you,
I have a piece of furniture that probably because it has not been allowed to dry properly, has a few matted dust stains (I think) stuck on it... and I would like to refinish it but using the same type of bait, in that idea I am asking.
Good morning. I used a one-component acrylic resin based floor varnish in 2 coats. The question is can you give another coat of water based varnish over it.
Good evening.
Yes, it can be given. The condition is to sand the acrylic layer beforehand to improve adhesion. The water-repellent varnish is compatible with many types of varnishes, but if it does not adhere well to the layer underneath it can flake like a skin.
All the best!
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Hello
I have a black table with glossy nitrolacquer, it has faded and scratched.
Thank you
Hello.
Is it painted with black paint or is it painted with black paint and then varnished with clear varnish? If it is with paint, then clean it of the dirt accumulated over time (wash it with water and detergent and then wipe it well and let it rinse). Then apply gloss black nitro paint.
If it is with black dip and the dip has scratched, remove the varnish, re-apply the dip and then apply clear nitro varnish. If it is only scratched lacquer, clean the table as above and apply a coat of clear gloss nitro lacquer.
Good luck!
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Hello. Please tell me what I can do to get over that lake that was in my grandmother's time. I have a cupboard that I want to change the colour of and I thought of sanding it first, but I understand that sanding that varnish does not work. So what do you advise me to do? Thank you very much!
Hello.
I'm guessing it's that shiny (polyester) lake from back in the day.
Any varnish can be sanded, only in the case of this varnish it will be much harder.
You can paint it with chalky paints. In this case you don't need to sand it but only to clean it (wash it with water and detergent) very well before painting so that there are no traces of wax from the maintenance products used (like Pronto). With the first coat it will be a bit harder because you will have to let it dry longer.Below you have 2 links for inspiration.
If you only want to darken the colour a little, but the finish remains transparent, you can use tinted nitro varnish. In this case you will have to sand the varnish so that it has adhesion. You can try first with a larger grain (150-180) to make it easier, then go back to fine grain (280-320) to avoid scratches. It is more difficult than painting, but it is the only way the finish can remain transparent.
All the best!
https://revistadinlemn.ro/2018/01/23/vopsele-cretoase-annie-sloan-chalk-paint/
https://revistadinlemn.ro/2018/02/21/transformarea-mobilei-cu-vopsea-pe-baza-de-apa-annie-sloan-chalk-paint/
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Thank you!
https://revistadinlemn.ro/product/abonament-revista-din-lemn/
Thank you very much for your reply!
Hello!!! I am bothering you with a question, you are the man I trust! On a solid oak table, with resin river, I can top it with matt varnish! Resin, with what kind of varnish is compatible? Thank you, have a nice day!
Good evening.
I'm not sure I got that right. Is it oak combined with epoxy resin? If so, you can apply a matt varnish, but sand beforehand so that the varnish has better adhesion to the substrate.
All the best!
Hello I have a question to you I want to use nitro varnish to give shine to a table and its legs and I would like to know how to dilute nitro varnish? what composition should I use to spray it with a spray gun .I mention that the nozzle of the spray gun is 0.8 mm
Thank you in advance
Hello.
The nozzle is very small, it should be 1.5 or 1.8. That way you will have to dilute the varnish a lot and when you spray there will be a lot of varnish in the air and very little varnish on the table. Use nitrocellulose thinner or universal thinner. Dilution depends on the viscosity of the varnish you use (how thick it is). For the nozzle you have you will have to make it almost like water. Being so dilute you will also have problems with leaks on the table legs. It is best to change the nozzle. At a nozzle of 1.8 more than 10-20% you should not dilute.
All the best!
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Hello. I have a question. I have some wooden stairs varnished a reddish shade. (I don't know what kind of varnish was given). I would like to give a wenghe varnish. How should I prepare the surface, or can I give darker varnish over the old one? Thanks
Hello.
Wash the surface with water and detergent to remove dirt accumulated over time, then sand with fine abrasive sponges or 280 or 320 grit sandpaper. To avoid incompatibility problems apply a wenge coloured water-based varnish. They are compatible with almost all types of varnish. Sanding is done so that the new varnish adheres to the old one.
Good luck!
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Thank you!
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Hello, I have placed an order for a wooden countertop ( pin) for the bathroom ( I will cut out the center and put the sink). The thickness of the countertop is 43mm, and it is dry. Question: how should I protect it from water. Thank you very much
Hello. I also have a question. I tried to restore a table and two chairs, first applying Borma Wachs bait diluted with technical alcohol, over which I then applied beeswax and linseed oil. As it was bright sunshine on the day I applied this treatment to them, there were no problems the next morning. However, yesterday it rained (the table and chairs are outside) and today I noticed that some colour had set in on the chair cushions. Then I read and saw that the wax was meant for indoor products. Is there anything else I can use over this wax to protect the product and keep the color from taking? Thank you in advance for your reply.
Hello.
Unfortunately wax is the final coat and you cannot apply anything else. For the outside, bait and oil was enough.
I still find it strange that the wax was so quickly washed away by the rain. Even if it's not outdoor resistant it can't be washed off in the first rain. That would mean that if you now wet mop the furniture you would get the wax off without any problems. If you have applied oil over the wax it is possible that the oil has been washed away. The oil is applied before the wax. With wax as a barrier it cannot get into the wood and remains on the surface without being able to get hold of anything.
All the best!
Hello! I have used Wood varnish, Savanna 2 in 1 for fences and cottages, 5 l, Wax for showers due to its properties, antifugs, anti-mildew, etc., but it has no gloss, I would like to know if it is compatible Wood varnish, Savanna Teflon, 2.5 l, Colorless, Glossy as a final coat.Thanks in advance!
Hello.
As far as I understand they are 2 different products. One is an outdoor varnish that contains insectofungicidal substances, the second is a wood varnish. If they are both made for outdoors they should work. You should see what it says on the label or ask a Savana representative. It is impossible for me to know all the products of all the manufacturers.Normally the label of the Teflon based varnish should say what it can be applied over. But if one is for outdoors and the other for indoors it might not work well, even if at first glance there is no problem.
All the best!
Hello,
I have problems with plastic components, after painting, cracks appear,, the paint is based on thinner.
I would be grateful if you had any advice.
I worked on the plus and minus viscosity but still .
I mention that this problem occurs 2-3 times a year which could be the cause?
Hello.
It could be from atmospheric humidity, drying temperature or coating thickness. You need to see what is different from normal conditions when cracking occurs. If they don't occur the rest of the time it is clear that there is an incompatibility between the paint and the plastic components. The variables remain the atmospheric conditions (humidity and temperature) and influence the drying and the way the application is done.
All the best!
Hello. I need your help.Can you tell me if water/solvent based paints can be applied over previously varnished surfaces.I have heard different opinions,contradictory,but not from a specialist.I want to recondition a railing that was previously primed with nitrolac.I sanded it with a 150 grit abrasive and would like to apply a water based paint.What do you recommend?Thank you.
Hello.
You can apply water-based products over nitrolac. You have to sand beforehand and I understand you have done that. After sanding apply water based paint. For good coverage you need to apply at least 2 coats. In between coats, after drying, sand to get a smooth surface with a nice touch.
Nitrocellulose varnishes cannot be coated with polyurethane varnishes or any other solvent-based hardener varnish. In this case the film will crack. With water-based products there are no incompatibility problems, but the surface must be sanded beforehand so that the new coating has adhesion (as you have done). Without this sanding the waterborne varnish/paint does not adhere well and can peel off (behave like a skin - it can be flayed) if the surface is lightly bumped or scratched. The only exception are chalky paints (Annie Sloan paint). But they must be "sealed" with wax at the end.
All the best!
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Hi. I left another comment but I don't think it was posted because I don't see it in the comments section below. I would need your advice.I want to refurbish a railing that has been nitrocoated. The posts I would like to be white and hence the problem. I've seen that Sadolin have white solvent based varnish.Do I paint them with water based paint?Is it compatible?How does it look better?Does the paint cover the surface better than the varnish?I'm not a specialist. I have asked both in the shops and at the production but the opinions are contradictory.I saw in the comments that you recommended Annie Sloane paint to someone. Please help me, thank you.
Hello again 🙂
You have the answer below.
Use solvent-based paint only if it is all nitrocellulose (such as nitrolac). I.e. white nitrocellulose paint.
As I said below you can use water-based paint, but you need to sand beforehand for adhesion.
The varnish is a transparent product, the paint is what covers it. That is, if you want to see the natural design of the wood apply varnish, if you don't want to see the wood, give paint.
You want to have a transparent railing and white posts (I hope I understood correctly). In this case you should use white paint. The alternatives are nitrocellulose paint or white paint. I would use water based paint to avoid smells. Especially since you have already sanded the surface of the poles.
Good luck!
Thank you for the information. I really didn't know where else to turn.Yes, the surface I sanded with 150 grit abrasive and I think I will paint the posts with Annie Sloane paint. I have seen that it covers very well.The current coat I will probably give it with a dark shade.For the posts I didn't know what to use.Once again,thanks for the advice.
wow ! finally we have an expert that we need very much .I am a carpenter and I am forced to use water-soluble varnishes that I do not like and that behave relatively differently depending on the manufacturer and environmental factors .I have a question, sanding between coats, primer varnish and varnish, varnish is done on all coats as with polyurethane, or just before the last one ? to avoid the so-called sieve effect? and can the effect I like, the smooth effect of polyurethane, be matched by the water-based varnishes that are in vogue, not to say imposed now? Thank you in advance.
Good evening!
Thanks again for your appreciation.
My opinion is that to get a good quality surface and good adhesion it is good to sand after each coat. That is if at least 12 hours have passed after application and the varnish is completely dry. Without sanding, apply only by the "wet-on-wet" method, i.e. after the varnish has been wiped off but not completely dry, so that the applied layer adheres to the existing one.
In the case of polyurethane varnishes, the surface is very hard and allows a very good sanding, which results in a smooth, glass-like surface. On this surface the varnish sands and spreads very well. Hence the very good quality of the finished surface. The water based varnish has a lower hardness and a more gummy resin, the sanding is a little more difficult and the final varnish looks like it is not perfectly spread. This aspect is less visible or almost invisible in good quality, professional varnishes. In this case a certain technology is followed, with primer and varnish, which allows easier sanding and better loading of the surface.
I understand from the phone conversation that you have more questions. You can send them by email mihaela.radu@cesbrands.ro. It's easier for me to answer that way.
All the best!
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I also have a question; I have some wooden doors painted 30 years ago, I guess it was oil based paint, could I paint them now with water based paint?...
Hello!
Normally oil-based paint and water-based paint do not mix. Even if it is old and the oil has worn off over time, by sanding the surface for adhesion you get to the lower layers where the oil is still present and the normal repulsion between water and oil takes place. The appearance of such incompatibility is similar to that given by cracked paint (broken film in many small islands).
Water-based paint is compatible with many types of paints and it is best to try it on a less visible area. Old paint may be of a different type and be compatible.
All the best!
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Hello,
Please help me with the following problem: on a northern pine floor I have given a coat of primer, two coats of bait and two coats of azure varnish (https://www.coramet.ro/ProductPdfFileHandler/767.pdf) Coramet salesman; I don't think I respected the drying time or it was wax and came out stained, please let me know if there is a solution/fix without sanding, I was thinking of a coloured varnish (wenge to be sure it covers the stains) and then 2 coats of floor varnish .But I don't know which would be combatable.
Hello!
From the data sheet I saw that the varnish is alkyd. In this case you can use coloured alkyd varnishes, alkyd paints diluted with white spirit (petrosin, turpentine) to avoid total coverage or oil-based varnishes/paints. Use one coat of coloured varnish and one of clear varnish. There have already been other coats before and the layer becomes too thick. A thick coat, besides the plastic look, also has a high risk of cracking due to the decrease in elasticity of the varnish layer.
All the best!
Kober 3×1 or 2×1 dark brown varnish (based on alkyd resins) can be applied over a wood previously varnished with Dyomarine colourless varnish (one-component alkyd-urethane). The Dyo varnish I applied to the exterior 10 years ago after previously treating the wood with Dyo Pinostar wood stain. Or would it be better to still use a Dyomarine matt, dark brown varnish.
Thank you!
Hello.
Being both alkyd they should be compatible. The problem is that 2 in 1 or 3 in 1 products have impregnant in their composition that is supposed to get into the wood and protect it from the inside. If you apply it over something already existing you lose this property.
Another problem is that some of the finish has already come off the wood. There is a danger that, in time, the frame will also come off, with the finish on top.
When you apply varnish over the old varnish they do not react with each other to make a single layer that clings well to the wood. The varnish sticks to the wood where the old varnish is skipped and to the varnish where it exists. The adhesion to the lake is lower than that to the wood. Over time some sort of fracture in the film can occur at the boundary between the two areas, because they behave differently. Recommended in such situations is the removal of the old layer and the application of a new one.
If the old finish has bounced off the wood, no matter what product you use (Kober or Dyo), you need to remove the old coating completely to have a good resistance over time. Otherwise it will only be a solution for a short period of time, after which you will have to repair again.
All the best!
Hello,
I know it's not exactly the subject of the article but I have the following situation: I have an old guitar that I want to start a restoration process. It's more a desire to experiment on it to see what can come out, if it can be used afterwards (initially I wanted to keep it as a decoration, although it's not a big loss if it doesn't come out a good job). Specifically, I would need some advice: what kind of putty can I use? what kind of varnish is recommended? What should be considered in the case of paint? what kind of varnish should I use? what adhesive can I use?
I'm mostly interested in what materials are intended for this type of wood, guitar? I don't want products that are too specific and costly.
Thank you.
Hello.
Unlike violins, guitars don't have very high finishing restrictions. Even less elastic products, such as polyurethane varnishes, are used in the factory for finishing.
In your case I would recommend using nitrocellulose varnish. It is simple to use and gives good results. I would not recommend a water based varnish, as there are problems with water absorption and the possible problems it can bring (peeling, patches).
The steps of the refurbishment are as follows
- removing the old varnish layer. It can be done by sanding with coarse sandpaper (60-80), after which the surface is wiped with thinner and sanded with finer sandpaper (180-220). Another option is to use a paint stripper (e.g. Decanol). Apply it on the whole surface with a brush, let it work, then remove it with a spatula (a spatula). You may need to do this 2-3 times. Finally wipe the surface with thinner.
- repair the defects and glue the loose parts. You can use wood putty or putty made from wood dust and acrylic or wood dust and nitro varnish (if this is what you will use for finishing). The mixture should have the consistency of a paste. Overfill the holes as it will dry out. Allow to dry and sand to level. Glue the loose parts with aracet (wood glue).
- colour in the desired colour using a water-based or solvent-based bait. If you have used nitro varnish putty use only solvent based putty. Otherwise stains will appear in the putty areas.
- apply the nitrocellulose varnish, with a brush, in a not very thick layer. A varnish film made up of several thin layers is more resistant than one of the same thickness in a single layer. Sand between coats, after drying, to obtain a thin film with a pleasant feel. Finally apply a coat of colourless wax and polish it the next day with a soft cotton cloth.
Good luck!
Well I have some pieces of wood shavings and I want to highlight the fiber very hard, how could I do it?
Hello!
By staining with a water-based bath. The water penetrates deeply and brings out the wood design very well. But if it is beech wood, it is better to avoid water-based stain and use a solvent-based stain. Beech stains from water.
Before applying any type of finish (varnish, oil, wax), allow to dry thoroughly (for safety, 24 hours).
If you don't want to stain the wood you can finish it with oil (linen or tung oil). Oil brings out the natural grain of the wood very well.
All the best!
Hello,
I made a kitchen countertop, a "country" kitchen out of raw MDF. I have applied solvent based wood primer over it and want to paint it with water based paint. Is this ok?
For info: over water-based wood paint, can water-based varnish be applied?
Thank you!
Hello.
Water-based paint can be applied over solvent-based primer. The condition is that the primer is very well dried and that you sand the surface of the primer a little before applying the paint. Sanding is done with fine abrasive sponges or sandpaper with a minimum grain size of 280. Sanding is necessary for the paint to adhere.
Water-based varnish can be applied over water-based paint. As above, you should lightly sand the surface beforehand. In this case the grain size of the paper is very important. If you use paper with a grain size smaller than 280 (coarser) it is possible that fine sanding curls will be visible through the varnish.
All the best!
Hello,
What option do you recommend for treating/lacquering a floor on an outdoor terrace, so that it is sufficiently protected against moisture, sunlight and mechanical shocks and requires minimal maintenance afterwards?
Thank you
Hello.
It's hard to find one that covers them all, in the sense that you won't find an exterior varnish of the hardness of an interior floor varnish. To provide protection to the wood and not crack when the wood moves, the varnish needs to be elastic. And an elastic varnish is less hard.
In my opinion you should focus on protecting the wood against moisture and UV radiation. In my opinion, the most suitable option is oil-based stained varnish. The oil will protect very well against moisture and the pigment in the varnish composition will protect against UV radiation. Maintenance is simple. Basically, as soon as the wood takes on a drier appearance suggesting that the oil has been removed by precipitation, apply another coat of varnish.
The floor can also be treated this way. If the wood is harder, it will hold up well. But it's best to use treated wood for exterior floors, such as that used for decking. The wood is treated in autoclaves and becomes hard and durable.
All the best!
Thank you very much for your answer. I would, however, like to see if I understand correctly - for the flooring I will use pine post. In this case, for protection against moisture, UV and mechanical shocks, is only oil-based stain sufficient or is it necessary to pre-treat the wood with something else and if so, with what so that the two are compatible?
Oil-based coloured varnish is sufficient against moisture and UV radiation. The mechanical resistance is not like that of a hard parquet varnish. It is still an oil.
For protection against insects and mould it is best to treat with an insect fungicide solution beforehand. These are water-based solutions that are given as a first coat. Then let the wood dry thoroughly (2-3 days) before applying oil-based varnish.
All the best!
Hello! I have a guitar factory finished with polyurethane varnish. I want to recondition it, but I want to get a matte ai texture not necessarily lacquered. What steps should I follow? What do I remove lacquer most effectively with? Thank you!
Good evening!
For a matt look you can apply a coat of nitrocellulose matt varnish. Simply sand the surface lightly to give the varnish adhesion. Look for deep matt varnish or natural matt varnish (gloss level 10-15 gloss).
If you want to remove the entire finish coat, the easiest way is to look for a paint stripper. Being polyurethane varnish it will be quite difficult, but not impossible. In DIY stores I found Decanol, from Policolor, but there are other products. Apply with a brush on the whole surface, let it work and carefully remove the soaked varnish with a squeegee. Repeat 2-3 times to remove all the varnish. Finally wash with thinner, sand the wood lightly and allow to dry. Apply the desired gloss varnish or oil. With oil you will have a very natural look.
You can also separate the lacquer by sanding with coarse paper (60 or 80 grit), but it is more work. After removing the varnish, sand the wood with 180 or 220 grit paper before applying the varnish.
All the best!
Can I apply water-based varnish to a floor coated with linseed oil after the oil has dried?
And another second question: before the water-based varnish is it mandatory to prime the raw wood? We are talking about resinous flooring.
Hello!
- You cannot apply water-based varnish over oil. Oil-based products or alkyd resins can also be applied over oil. Oil does not mix well with water.
- Apply primer only if the lacquer you are applying requires it (it says on the label that it can only be applied over one coat of primer). If not, it can also be applied directly to the wood. In order for the surface not to be rough you will have to sand well before and between the coats after they have dried.
All the best!
Hello.Please tell me what I can do since the craftsmen who made my doors brought them ready painted with a reddish color when I wanted to color them a sonoma oak.I decided to turn them off the color (vengeance).They used sticky varnish (glossy alkyd varnish) and I want a more matt varnish.I mention that on a piece of painted wood that remained, I sanded it lightly then I gave 3 coats of savana venghe without teflon and it is water based.It did not make any reaction in 24 hours but I am afraid to start painting the doors.Please give me some advice.Thanks
Hello!
The problem in your case is not the lack of incompatibility but the resulting final coating which may be too thick. The colour can be changed, as you have already done, by applying another water-based varnish over the existing varnish. A light sanding must be done so that the new material applied adheres to the old one.
In your case, however, there is a top coat that I think is quite thick. The fact that it is so glossy that it bothers you clearly shows that several coats were applied. If you apply 3 more coats of another varnish you might find that the material deposited on the board will reach more than 450-500 g/sqm. In this case there is a danger that the varnish film will crack over time.
For safety sand the doors better, not just superficially. In this case, part of the initial varnish layer is removed and the risk of cracking over time is reduced.
Another option would be to have the craftsmen remove all the varnish by mechanical sanding and apply the new finish as you wish.
All the best!
I have a pine floor lacquered with boat varnish and I would like to relacquer it.Can I apply water based varnish and how should I prepare the lacquer surface?Thank you!
Hello!
If you just want to freshen up the look, simply wash the surface to remove dirt and grease that has built up over time and sand gently to increase the adhesion of the varnish. Sanding is done with fine abrasive sponges (or 280 or 320 grit sandpaper). It is a superficial sanding, do not insist. After sanding, apply varnish (1 or 2 coats, drying in between).
If the old coat is damaged in some places and the wood has been reached, in order not to have the surprise to jump with the new coat, it should be totally removed, i.e. the shower should be scraped and the finish applied from the beginning. If you can't scrape the whole surface, at least in the place where the wood has been reached you should insist on sanding and remove the surrounding lacquer, down to the wood. Repair the area first by applying 2-3 coats of varnish with drying in between, then varnish the entire surface.
All the best!
Hello,
I need some advice, I accidentally painted some door frames with varnish over old paint. Although the colour looks great, the varnish has run off making various marks. Can I paint over the varnish after it dries well?
Or should the varnish be removed and then painted?
Thank you!
Hello!
The problem is that the new layer is not absorbed at all and cannot even catch the old layer (the paint) because it has not been sanded before to create some roughness. You should have applied with a stiff sponge pad, there would have been a better chance that the varnish would have adhered and not leaked (the amount applied is smaller).
To apply over the varnish you need to be very dry and sand a little with a fine abrasive sponge (found in DIY stores) to create the roughness I mentioned above. If there is no rejection between the paint and the varnish (cracks appear or the varnish film is not continuous, it is a cluster of varnish islands), the products are compatible and you can apply over the varnish.
In conclusion, if the varnish and paint are compatible, you can apply paint over the varnish if the varnish is very well dried, lightly sand beforehand and apply small amounts to avoid spills (the application is vertical).
All the best!
Happy Birthday!
What layers should I combine for a rough plywood surface, so that the wood grain stands out but I end up with a glossy protective surface (to withstand light rubbing)? This is a musical instrument for reconditioning. As a non-specialist, I was thinking a bit of natural, dried and then sanded, then an acrylic gloss varnish. I appreciate any advice.
Thank you?
I mention that the wood has been cleaned of the old paint down to the grain and sanded.
Hello!
Acrylic varnish cannot be applied over linseed oil. My opinion is to use a nitrocellulose gloss varnish. You can apply 2-3 coats of nitrocellulose primer first, with sanding between coats, then apply 1-2 coats of nitrocellulose gloss varnish. At the end, to get a perfect gloss, you should polish the whole surface. To better highlight the wood grain, you can initially apply a thinned wood stain in a natural colour (walnut, oak). The Romanian factories producing violins also work with nitrocellulose system. They always polish the instruments to obtain that perfect shine.
If you want to use oil, it is best not to apply anything else on top. You will get a natural looking surface with a very nice satin sheen. Only alkyd or oil-based products can be applied over oil.
All the best!
Happy Birthday! 🙂
Hello.
Very interesting article. I want to make a painting with pieces of wood. Can I varnish them before applying epoxy resin? ( I mention that the resin will cover the pieces of wood at the end) or only after the resin is hardened and the surface has been sanded ?
Good evening!
Generally, the varnish is given at the end, after the resin has hardened and been sanded. Varnish, if polyurethane, gives better resistance to high temperature and scratching.
But I don't understand why you want to apply varnish on wood before resin? For what purpose?
All the best!
Hello. Your articles have always been helpful to me so far, as I am not a professional and like to do small projects around the house. I have an outbuilding that was treated many years ago with used engine oil. Being exposed to the sun the facade has discoloured during this time, the wood turning almost grey and being very dry. Over this wood what kind of paint could be used so that it has a good coating? I would like to paint the facade in a brownish shade. Thank you.
Hello!
Glad I could be of help.
If the wood is dry, the oil has been removed by the weather. The grey colour is from UV radiation. Transparent oil does not protect against the sun's rays.
Oil pruning should be redone after 1-2 years because the oil is removed by rain. After much longer there is no more oil and you can apply any finish. You can find commercially available water-based exterior paint of various brands in the desired colour or alkyd paint, solvent-based. Alkyd paint is the equivalent of the oil-based paint used in the past. It is hard-wearing and protects very well.
Good luck!
Hello
I applied, with a roller, a coat of alkyd savannah paint on the old doors in the apartment assuming that they were blown in oil because they were very shiny, uniform, without brush marks. The paint applied well, covered well, looked good but... accidentally I found that the film peels off with a simple scratch with the fingernail (it does not flake, it is elastic) the previous paint remaining intact. They were given 2 weeks ago and I admit, I didn't insist with the matting because they scratch very hard.
Please let me know your opinion on the most likely cause (is it possible that the paint is not completely dry yet? but what could it have been, etc.) and if there is something that can be done.
thank you very much
Hello!
It's the lack of grip. The purpose of sanding off an old coat of varnish (or between coats), matting as you call it, is to create little curls in the old film for the new paint to get into. This is how you make the bond between coats. Otherwise, at the slightest knock, the new film will peel away from the old one and air will come in between them. From here to the paint flaking off is just one step. As the surface is glossy, it needs sanding all the more. In order to reflect light perfectly - the main condition for surfaces to have gloss - they must be very smooth and straight. On such a surface it is very difficult to have adhesion.
The paint can be applied without sanding only if it is possible that the coats will stick to each other otherwise. For example, if the old coat is nitro and nitro is applied over it. The thinner in the top coat softens the bottom coat and so the 2 coats bond. But in your case, the old layer has hardened by a chemical reaction, not just by evaporation of the solvent. The proof is that wiping with thinner does not remove the old paint. The only possibility that the two layers are connected is the creation of a fine roughness by sanding.
Unfortunately, there's not much you can do and I don't think that, being already 2 weeks after the application, things will improve. You will have to use the doors carefully and repaint them when the look goes bad.
All the best!
https://revistadinlemn.ro/2017/01/16/ce-este-si-de-ce-este-importanta-slefuirea-intre-straturi/
Thank you very much for your reply although it is not at all gratifying. I take it the previous paint was most likely not oil based but nitro? I still have to apply to the front door and it's important to know.m
It's possible, although that's not what I meant by the nitro example. You can check if this is the case by trying to wipe off the old paint with a universal thinner or acetone (not petrol or derivatives). If it takes, it is nitro and you can apply nitro paint on top of it without having to sand (matte). From what I understand, it's the entrance door to the apartment, not an exterior door (nitro doesn't hold up in outdoor conditions - rain, sun, etc).
But it is not the only possibility. It can be alkyd paint, polyurethane paint, carbamide paint, etc. They were all used 30-40 years ago and could have a very glossy appearance. In this case you have to sand for adhesion. Sanding is done with a fine abrasive sponge or 280 or 320 grit sandpaper so that the fine lines are not visible through the paint.
So, if the old paint is taken off with acetone, apply nitro paint, no sanding. If it doesn't, sand the surface and apply alkyd paint.
All the best!
Hello,
I would like some advice on protecting a fence made of planed pine wood.
What products can I use for protection and maintenance.
Thank you!
Good evening!
In my opinion, the best fence protections are oil-based coatings or waxed outdoor impregnations. Varnish is an oil or mixture of oils slightly coloured to resist UV radiation. It is a moisture resistant product (the oil does not get wet) that is easier to maintain compared to filming products. The latter will flake off over time and in order to restore the finish the old coat must be completely removed and a new one applied. With oil-based products maintenance is much easier. The oil is washed off over time and at some point it takes on a dry appearance (oil gives a wet, living appearance). This is when another coat should be applied, without having to remove the old coat. It is enough to clean off dirt (wiping with a wet rag) to get a nice look.
Waxed specimens behave in much the same way, but are less hardy. If oil-based products (Kreidezeit) are available that last 4-6 years (depending on exposure, climate and frequency of precipitation), the waxed impregnant finish should be redone after 1-2 years.
Below are 3 links that you may find useful.
All the best!
https://revistadinlemn.ro/2018/03/09/garduri-din-lemn-cum-se-alege-lemnul-materiale-de-protectie-sfaturi/
https://revistadinlemn.ro/2018/06/25/8-cele-mai-frecvente-intrebari-despre-protejarea-lemnului-la-exterior/
https://revistadinlemn.ro/2019/04/17/7-reguli-de-respectat-la-finisarea-cu-ulei-a-lemnului/
Hello,
Does the solution of protecting the fence with 1 coat of impregnant followed by 2 coats of alkyd varnish seem a good solution to you or will the varnish coat flake over time?
Thank you for your kindness and reply.
Good evening!
The alkyd varnish forms the film. It's a fairly durable varnish, like alkyd paint, but over time, the film can crack, water gets underneath it and it flakes off. To restore the finish, the old coat must be removed and a new one applied.
The reason I recommend the use of oil-based lacquers or wax impregnators is simpler maintenance and refinishing. As the fence is always under rain and sun, the likelihood of problems occurring more quickly and requiring maintenance is greater. But your proposed option is not bad, provided the impregnant is not waxed. Wax is the final coat.
All the best!
Hello!
I have some decorative wooden beams in my house that have been given a mahogany stain and I would like to change the colour to a light brown...oak. What do you recommend?
Good evening!
Being a lighter colour than the existing one, it would be best if you stripped, sanded the wood, then applied the oak berry over it with wax or oil.
A simpler option would be, if the beams have been varnished over the bath, to apply a coat of oak coloured varnish. It won't open up the beams very much, but you'll be left with visible wood grain.
The easiest way is to apply a paint in oak colour. The wood grain will no longer be visible, but the colour will open up. Before applying the paint make sure that the two coats are compatible (apply paint to a small hidden area). If wax has been applied to the beams neither material will adhere until the wax layer is removed by stripping or sanding.
The steps for repainting can be found in the link below.
All the best!
https://revistadinlemn.ro/2020/10/29/ce-trebuie-sa-stii-daca-vrei-sa-revopsesti-mobila-sau-usile-de-lemn/
Hello,
I bought a 20 mm solid oak floor oiled with linseed oil.
Can floor varnish be applied over linseed oil?
Thank you in advance for your answer.
Hello!
Over linseed oil you can only apply alkyd varnish. But after at least 6 months of use, when the oil on the wood has been removed by use, you can apply floor varnish. It's best to check the adhesion beforehand, in a more hidden place. If it is low, postpone the varnish application for 2-3 months.
All the best!
Hello,
Please help us with an answer for the following situation: white matte oil-based paint mixed with thinner has been applied to some pine wood doors (which have been sanded before). The orange peel effect has appeared and we don't like it. We would like to paint them with a white water based matt paint, can this be done after sanding again? Is there anything else we need to consider in this situation?
Hello!
Water-based paint does not work over oil-based paint. You'll need to remove all the paint, down to the wood, then refinish with water-based paint.
You can, however, remove the orange peel effect by sanding the paint layer with 280 grit sandpaper or a fine abrasive sponge along the grain, without removing the entire layer but only the top part that has orange peel. Remove the white dust that has formed and apply another coat of the same paint, which you thin more to avoid orange peel. The orange peel effect forms when the coat applied is too thick.
Good luck!
https://revistadinlemn.ro/2016/04/06/defect-de-finisare-coaja-de-portocala/
https://revistadinlemn.ro/2017/01/16/ce-este-si-de-ce-este-importanta-slefuirea-intre-straturi/
Hello, I have asked for your opinion in the past and now I have an exterior door to finish.
I want to give it linseed oil and after it dries I bought Holzwachs Lasur - wood polish with wax. Is it ok?
Is the order right, i.e. oil in first and after drying the few coats give with this oil?
Thank you so much for the information so valuable for us first timers. Hard today to find someone willing to give you accurate information about anything.
Hello!
Thank you for your appreciation too!
Impregnating with linseed oil helps reduce the amount of lard consumed, but it does not give you good protection on the outside. You can apply 2-3 coats of linseed oil without saturating the wood. Give it a chance to absorb the varnish as well.
Make sure the lacquer is for outdoors (not familiar with the product mentioned). Adding wax does well, increases water resistance.
Good luck!
Hello,
I made a countertop for the sink in the bathroom, from natural oak wood, oiled and polished. It is bought from Hornbach. It is already very well dried, when you cut it you can see that the oil has penetrated almost all the wood.
The problem is that it stains easily (for example it stained under the liquid soap container). I have a professional water based varnish, but I don't know if it goes over. I mention that the surface is not mirror finished, , nor do I want to get gloss ! What do you advise me ?
Hello!
Water-based varnishes do not go over oil. You must use an alkyd varnish, based on white spirit (petrosin, gas).
To avoid gloss you need to make sure that the varnish used is matt. Write this on the label.
All the best!
Thank you very much! However, alkyd varnishes do not stain in water?
No. Acrylic resins are the basis of exterior paints, they are moisture resistant.
Hello!
I read the article with interest looking for an answer that I cannot find. I would like to rebuild the fence and the planks which are made of resinous wood, I intend to give them a dark walnut bath, and linseed oil. I don't know what kind of bait would be compatible with the additive oil, and also UV resistant.
Thank you very much!
Hello!
For outdoor use, there are special UV-resistant baths. You should look in the shop for baths that are specified as outdoor resistant.
Simple baths, without any other addition of resins, those with only solvent, i.e. only water, or organic solvents, after drying, can be coated with oil without any problems. That is, you can use water-based or solvent-based, exterior-proofed baths, provided that the oil is applied after it has dried completely.
Lacquers or other coloured outdoor materials must be oil-based or alkyd resins to be compatible with linseed oil.
All the best!
Hello!
We started building a terrace. The wood was green, dried for a few weeks until the humidity dropped, then it was coated with Bochemit Opti F, then 2 coats of linseed oil. We don't know what would be better to apply as the next coat - white oil based paint or varnish. Do you have any recommendations for a paint that applies beautifully, is UV and weather resistant? We would like whatever we end up giving, to work the date on the metal joining elements as well.
Thank you
Hello!
The paint is more weather resistant than the varnish, and the white varnish is not very UV resistant. You can apply oil-based paint from Kreidezeit. It goes over linseed oil, is durable and is the equivalent of the old oil paints that were applied over everything.
Good luck!
I'm bothering you again with a question about a curtain rail. It is old wood veneered as it once was with a glossy veneer. As far as I know... I think it is. I want to paint it blue, I would like a water based paint. What do you recommend would be best?
Thank you very much!
Back again...I read about your Annie Sloan Chalk Paint. They have in gorgeous abstract, could I use it for the gallery?
As I said above, you can use it provided you apply wax on top to fix it.
Good evening!
You can use any water-based paint. Before painting you should degrease the surface with water and detergent to remove dirt and grease accumulated over time. How to clean is described in detail in the article on repainting. You have the link below.
If you are using a regular acrylic paint (water-based) you must sand the surface of the gallery beforehand so that the paint adheres. Sand with 280 or 320 grit sandpaper or a fine abrasive sponge. Sand along the grain of the wood. After sanding, roughen and apply the first coat of paint. Leave to dry for 1-2 hours and then apply the second coat without sanding.
If you use Annie Sloan or other chalky paints you can apply it without sanding. Degreasing with water and detergent is however necessary.
Apply the first coat with care and patience as the paint may slide off the glossy surface at first/ After drying apply coat 2. For durability Annie Sloan paint should be fixed with colourless wax or water-based varnish. More information is in the link below. I have also put other links to articles related to repainting, you may find them useful.
All the best!
https://revistadinlemn.ro/2020/10/29/ce-trebuie-sa-stii-daca-vrei-sa-revopsesti-mobila-sau-usile-de-lemn/
https://revistadinlemn.ro/2018/03/12/ceara-annie-sloan-protejare-patinare-tehnici-de-aplicare/
https://revistadinlemn.ro/2018/01/23/vopsele-cretoase-annie-sloan-chalk-paint/
https://revistadinlemn.ro/2021/03/04/vreau-sa-schimb-aspectul-mobilierului-ce-pot-sa-fac-fara-costuri-prea-mari-si-cu-efort-redus/
https://revistadinlemn.ro/2020/04/23/vopsirea-si-lacuirea-sfaturi-pentru-incepatori/
Hello!
Please, help me with some advice regarding an old wooden cabinet (from my grandparents' time) that I would like to rebuild. I should mention that I have already sanded it, and now I want to re-lacquer it so that the wood grain shows. From what I understand I have to give it a bait, then primer and varnish? Can you advise me on the order to follow and also if any sanding is needed after the primer.
Do you think I should choose a water-based or solvent-based varnish/primer/bait? Which are incompatible?
Thank you!
Hello!
From your post I don't understand if you removed the film down to the wood or just sanded the lacquer so the next coat would have adhesion. I'll answer for both.
If you have reached the wood make sure you have removed the pond completely. Sand the surface with 80 or 100 grit paper and then wipe with nitrocellulose or universal thinner. Sand again with 150 or 180 grit paper. If you want the wood to be stained but still see the wood grain, the first coat is bait. It's best to use a solvent-based bath so that the wood grain doesn't rise too much and there's no risk of peeling if the furniture is veneered. If you do not want to stain the wood but want it in its natural colour this step is eliminated. After the wood has dried, apply a coat of primer, let it set for 30-45 min, then apply the second coat. Leave to dry until the next day, then sand to remove raised grain and bubbles trapped in the film. Use 280-320 grit sandpaper. After sanding apply the final coat of varnish. Being an old cabinet, have I would use nitrocellulose varnish, it resembles the shellac used in the past.
If you haven't reached for the wood, to stain you'll need to use a coloured varnish. It's risky because if you go over the same surface twice a streak of colour appears. And the effect will be more plastic. It is better to apply a coat of clear varnish and/or a coat of wax to freshen up the look. Also apply varnish and wax if the top coat is too thin and you want a more consistent film. If it's nitro varnish or shellac (check on a hidden surface if it takes with thinner, link below), use nitro varnish. If it's another type of varnish, use water-based varnish. It is compatible with many types of varnish. Before application sand the surface lightly again so the varnish has adhesion. If you apply wax at the end, polish it 3-4 hours after application with a soft cotton cloth. The furniture will take on a very pleasant silky sheen
Good luck!
https://revistadinlemn.ro/2021/09/02/ulei-ceara-shellac-sau-lac-cum-afli-ce-este-pe-suprafata-mobilierului-si-cu-ce-il-poti-refinisa/
Hello! I would like to ask if it is possible to paint with white water based paint over water based varnish without glazing the surface? I made a wooden terrace in front of the living room and the wood was given with wenge water based varnish . I find the colour very dark and it also darkened my living room and I was sorry I didn't do the white terrace. I have tried on a piece of varnished wood to paint and it is catching the paint but is there a possibility that over time it will peel if I don't glaze the varnished surface ? Thank you!
Hello!
My advice is to sand. Water-based paints have some more special resins. Their molecules bind to each other very well. When you apply a fresh coat on top without sanding, it looks like everything is fine. But at the first stronger mechanical shock (bump), the layers peel off, and the top layer can flake off like a skin. Sanding creates the conditions for the top layer to grip the bottom one better.
Hello
Big request to you. I have been using water-based bath... Can I use linseed oil on top of the water-based bath?
Thank you!
I appreciate your help.
Hello!
Yes, it can. Provided the bath is thoroughly dried.
For safety let the bath dry for 24 hours.
Hello,
Very well written article, lots of useful information. I would however need some advice on staining/treating beech wood treads for interior stairs. I would like to give an oak stain before the final varnish and have done some tests with a wood stain (oskar silikon lazur solvent based) on the back of the steps but the result leaves something to be desired. Dark areas appear and the wood has a "stained" appearance. I sanded the wood very well beforehand with 180/240 grit sandpaper. What else could I do to get better results? I'd like something that would also even out the appearance of the wood, there is already a bit of a contrast between the various inlaid rulers that the step is made of. I'd also try a paint instead of bait, but I don't want to completely cover the wood grain.
Thanks for the advice!
Good evening!
Thank you for your appreciation too!
Beech is difficult to stain, it is very difficult to achieve stain-free staining if the stain is applied directly to the wood. For staining, uniforming or quick-drying, solvent-based stains are recommended. Normal water-based stains always stain.
One solution is to apply an insulator beforehand. Primer/paint can also be used for protection. As the aim is to regulate the absorption of the wood, the primer is diluted 1:1 with its solvent (water or thinner) and a thin layer is applied. It should not form a film but only absorb into the wood. After drying the wood is sanded (150 or 180 grit paper or medium abrasive sponge), stripped and the wood is then sanded.
To seal the surface you can use a solution of aracite in water (mix 1 part aracite to 3/4 parts water). Apply with a brush to the surface, and after drying and sanding the wood, apply the wood stain. More information can be found in the link below.
Another solution is not to use bath and the varnish (at least the first coat) should be coloured in the desired colour. This adjusts the absorption and makes the colour more uniform. Be careful, with each coat applied the colour darkens and the wood becomes less visible.
In the links below you can find more solutions for even colouring.
Good luck!
https://revistadinlemn.ro/2018/12/06/colorarea-lemnului-recomandari-pentru-un-aspect-fara-pete/
https://revistadinlemn.ro/2024/01/25/cand-si-de-ce-se-aplica-solutie-apoasa-de-aracet-pe-lemn/