How to remove stain from wooden doors without sanding or sandblasting

The reddish colour of the doors was the first complaint of the lady who asked my advice. She wanted to give the wood a more natural colour, without having to paint or sand them. She also wondered if there wasn't a material that would lighten the colour without the need for further intervention. Unfortunately, it is impossible to go from a dark to a light colour and still have the wood visible, i.e. not paint it. Also, there is no stripping material that will take an even coat out of the finish and thus make the door colour lighter and the wood more visible. The only solution is to completely remove the varnish and the bath and refinish.

In this case, as seen in the photos, the doors appear to be painted with a colored varnish, and the sheen and overall appearance and the fact that they were interior doors led me to think of a nitrocellulose varnish. The colored varnish, probably applied in 2-3 coats, made the wood design too inconspicuous. Let's take them one at a time and see why it's better to use bay and varnish, not colored varnish, and how the finish can be removed without sanding or sandblast.

Coloured varnish gives a plastic feel and loses the natural charm of wood

If you like wood and its natural pattern, varnishing with a coloured varnish is not the best solution. Successive coats of varnish applied will make the film more and more colourful and plastic-looking, and the pattern of the wood will be blurred. To highlight it, it should first be stained to the desired colour using a plain stain and then varnished with a clear uncoloured varnish.

A simple stain, i.e. stain and water or solvent, will be absorbed into the wood and thus highlight it. If there is a design formed by late and early wood, it will show up even better after staining due to differentiated absorption. If a coloured varnish is applied, the high viscosity will hinder absorption, everything settling on the surface like a plastic film.

There are species that are more affluent (plop) and can stain when stained. There may also be defects that will be highlighted by staining. In this case a first coat of coloured varnish can be applied, but more diluted. Absorption will only be superficial, the design will be highlighted, but the defects will not be so visible. Then apply only clear uncoloured varnish and the colour will not change, the film will be transparent and the wood will show through.

Paint stripper, paint remover or paint remover

These are the names under which you can find solutions for removing varnish or paint film in the shops. There are all kinds of these materials on the market, some stronger, some weaker, depending on the composition. They can be for a specific type of paint or universal.

The way it works is pretty much the same, regardless of brand. The paint stripper is brushed onto the painted surface and left for the recommended time. This time varies from a few minutes to hours, depending on the effectiveness of the paint stripper, the type of paint stripped, the thickness and age of the coat. In order to apply as thick a coat as possible and to stay on well when applied vertically, most paint strippers are in gel form. After the recommended time, the paint should soften and swell so that it can be removed with a metal scraper.

Varnish or paint films are thermoplastic and also soften with heat, using a hot air blower or hair dryer. The softened varnish is then removed with a squeegee, as above. The disadvantage is that it is worked in patches, and on large areas it becomes difficult. Find here method at length.

Removing nitrocellulose varnish with paint stripper, like the one on the doors mentioned, should not pose much of a problem, as it is one of the weakest varnishes, it cures very quickly. If it does not completely peel off from the first coat, repeat the procedure. Finally, wipe the entire surface with alcohol and then refinish.

Using thinner to remove varnish

In the case of nitrocellulose varnish, film removal can also be done without paint stripper, only with nitrocellulose or universal thinner. It is more work and more smelly, but effective. For this, the door is laid horizontally and rags/towels soaked in thinner are placed on top. As the thinner is very fluid, the rags will help it stay on the surface longer and soften the film. After 10-15 min, the rags are removed and the varnish is scraped off as above. Finally wipe the whole surface with a cloth with thinner and leave for at least 12 hours. A sanding of the wood before applying the bath will result in a more even absorption. If the natural colour of the wood is preferred, do not apply stain but go straight to varnish.

The method is more unpleasant because a lot of fumes and thinner smell are released. It is best done outside or in a dedicated space away from sources of fire.

I hope you find the information useful. If you have any additions, questions or queries, please leave them in the space below. I will certainly reply.