DIY Finishing - Finishing Techniques

Which varnishes do we use for wood protection, professional or DIY?

From time to time I log into the profile groups to see the new topics members post, as well as the problems they encounter and the advice they receive. Although I love all things wood, I'm watching the finishing related posts more closely. It is the area I specialized in many years ago and still have a great passion for. In groups there are always beginners who call on the knowledge of "veterans" asking what wood varnish to use, what lazura wood is the most durable or which wood paint would be best for his small project. From the recommendations I can tell that there are many rightly attached to good professional brands that they highly recommend. I understand their enthusiasm, but the end result depends not only on the quality of the materials. For years I've been telling those I work with that the materials are very good, but they can't work wonders. And I'll tell you why.

When to use professional finishing materials and why it is sometimes better to use DIY stores

There are two main product groups in the wood varnish and paint market, industrial and DIY. The former are sold by manufacturers or their distributors, the latter you can find in DIY stores. Industrial products are often sold after an agent visits the workshop or factory, while the others you buy yourself in the shop and try to find out as much as possible about the product and how to use it from the shop representatives or the label.

wood varnishes
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Professional materials

Professional varnishes and paints are made to be applied under certain conditions and with certain devices (gun, moulding machine, wand). In technical data sheets, which you should receive with your first shipment, the product is described, as well as the conditions that must be met to get the best result.

The temperature in the work area, what to apply, how much to thin, how to sand, how thick the varnish should be and much more are mentioned. You will always find a note at the end saying that sometimes the result can be altered by factors directly related to where the finishing is done.

It can happen that the same product, applied to temperature too low or too highwith a gun with a nozzle that is too large or too smallor in a space with much dust no longer look the same as one applied according to the chart. More is expected of industrial products than DIY ones, and that's why they are sometimes made of materials that increase their sensitivity. They are also part of systems, from technologies it is recommended to apply certain primers under varnish or some kind of sanding paper. They cannot be used anyway and in the end achieve perfect results. I'm sure that those who recommend the products apply them as directed by a company technician, which makes the results very good.

wood varnish
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DIY products

When you make a wooden chair or table for the first time and you want to varnish it, I doubt you can meet the requirements of the technical data sheet of a professional product. Nor will you get the assistance of a company technician unless they are your friend. So your best bet is to turn to DIY products.

These products are specially formulated to be applied at home with a brush, trowel or even a cloth, in less stringent conditions than in the factory. The result will not be perfect, but acceptable for a personal project. You will not need sanding between layers for grip, nor dust-free atmosphere for a decent shine. You won't have to buy 2-3 types of products to apply successively, but one product will deliver the desired result.

And in the DIY range there are many good brands with which you can achieve very good quality finishes. Many manufacturers of industrial finishing materials also have special divisions for DIY products, precisely to offer quality products to those working on personal projects at home.

If after a few of these projects you're thinking of taking it to the next level, then turn to professional products. But until then, it's best to avoid them because you may not get the result you want and lose trust in a good brand just because you can't follow its recommendations.

wood varnish
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Nitrocellulose varnish is the oldest and most versatile varnish, but it cannot be recommended for every job. It has its limits!

Another material I have seen recommended many times, regardless of the subsequent use of the finished object, is nitrocellulose varnish. It is considered a kind of universal panacea. I've also seen it recommended for fencing and other outdoor landscaping.

Nitrocellulose varnish is one of the oldest and most versatile varnishes, but it cannot always and under no circumstances be used for exterior finishes. Indeed, in the past, only this kind of varnish existed, but for exterior use it was not varnish but oil.

If good resistance of furniture to moisture, scratching or mechanical shocks is desired, nitro varnish is not the one to get. Bathroom or kitchen furniture finished with nitrocellulose varnish and on which water drips or even splashes will, over time, become runny.

For such conditions, catalyzed hardening varnishes - polyurethane - are recommended.acrylic, polyester. They are much more resistant varnishes. But even in this case the application instructions must be followed to achieve the desired result. So, if you have made a table for the first time and want to varnish it, don't think of a polyurethane varnish first. You might more likely create problems for yourself. Turn to a DIY product that will sufficiently protect the table. With time you will also learn how to remedy the problems that may arise.

wood varnish
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Bottom line:
  • Turn to DIY products if you're just a first-time wood enthusiast making something that needs protecting.
  • Always read the label for recommendations. If you need an outdoor product look for this specification. If it's not listed - don't get it.
  • Don't expect great results just because you use a product from a famous brand. When finishing wood, working conditions and technology are equally important.
  • If you are a professional but have never worked with a particular product before, don't bank on experience. Ask the supplier about conditions and application technology. Varnish types can be very different and so can the results.
  • Do not use nitrocellulose varnish for any kind of finishing. It is a varnish with many qualities, but by no means universal.

Good luck!

About the author

Mihaela Radu

Mihaela Radu is a chemical engineer but has a great passion for wood. She has been working in the field for more than 20 years, wood finishing being what defined her during this period. She gained experience working in a research institute, in her own company, as well as in a multinational. She wants to continuously share her experience with those who have the same passion - and more.


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    • DIY = do it yourself
      The term used for DIY stores.
      DIY varnishes are the ones from such stores that we buy for projects we have at home: painting a piece of furniture, a fence, a patio, etc.
      All the best!

  • Hello.

    I have read several articles related to wood finishing, but I still have some questions and I would be very grateful if you could help me with an answer.

    1) For the realization of a pine wood gazebo, do you have an article already written in which you present all the necessary steps to finish it? White sanding, priming (if applicable), sanding again, applying linseed oil or maybe lacquer is better. I searched through the articles already posted, I found suggestions for treating exterior wood, but I seem to have seen more for hardwood.

    1.1) Also related to the veneer, do you recommend sanding the used wood, or is just sanding with 80-120 enough? I know that the results are different, as we are talking about different mechanical processes, but I am curious which option is recommended to keep an authentic look.

    2) What do you recommend for treating OSB outside? We are talking about a small tool shed, so it is out of the question to cover with polystyrene and plaster like a normal wall. I understand the paint would peel over time. Am I to understand that here too linseed oil or lacquer would be more recommended?

    Thanks in advance!

    • Hello.
      1. We don't have one for a pine patio, but the finish is not much different from hardwood. Softwood (spruce, it's the one that is mostly found in our house) is used a lot for exterior and the strengths are good. It has to be sanded more carefully because it is more "suede" compared to hardwoods - oak, acacia. Sanding should be done with min.150, even 180 to get smooth surfaces. In general, exterior varnishes can also be applied layer by layer. In this case no primer is needed. For a smooth surface, sand between coats with 280 or 320 paper or fine abrasive sponges. If the label or the seller recommends primer beforehand then apply 2 coats of primer and one coat of varnish.
      The drying oil protects well against humidity, but not against UV radiation. For this protection it must contain a quantity of pigment. The oil contains pigments and is therefore more resistant than plain oil.
      1.1. I recommend sanding because the wood needs to absorb inside and it does it better when the wood is "scratched", there are several fiber heads that absorb protective substances (ilei, impregnant).
      2. You can protect it by painting it with an exterior resistant paint (oil-based paint). The problem with peeling is because it absorbs harder and cannot "stick" to the wood. Try a light sanding before applying the paint. But with OSB the problem is in the cut areas on the edges. That's where it starts to absorb and swell. Those areas need to be protected as well as possible from moisture.
      I hope that was helpful.
      All the best!

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