Paint Stripping Techniques

Chemical paint stripping can remove multiple layers of finish and reveal the woods true beauty. This process is usually reserved for interior woods that are either exotic in nature or have a historic value.

The exact method needed depends on the type of finish to be removed and the woods profile. The good news is that most paints and clear finishes can be removed with off-the-shelf products.

First a few words about safety. Stripping paint involves the use of some potentially dangerous chemicals.

• You need good ventilation. Open all windows and use fans to provide fresh air. Paint stripping can give off powerful fumes plus dissolving oil base paint will also produce fumes. If possible take the project outside.
• Extinguish all open flames and no smoking. The fumes given off during the paint stripping process can be ignited by pilot lights or hot halogen lights.
• Dispose of the removed finish by placing it into a metal can and allow to dry. When completely dry put into the trash. Solvent soaked rags need to be soaked in a pail with water before disposal.
• Wear protective clothing and chemical resistant gloves. Eyewear is also a good idea. Some strippers can cause severe burns on contact.

Basic Paint Stripping Procedures

It is very important to follow the specific label instructions provided by the manufacture. However there are some basic steps that apply to all paint and varnish removers.

Step 1) Identify the Woods Finish

Before you purchase and use the stripper the finish needs to be identified. Not all paint strippers are appropriate for all finishes.

Most clear wood finishes will be either an oil base finish such as Lacquer, Varnish and Polyurethane or a water base finish such as Acrylic Urethane and Water Bourne Polyurethane. Fortunately there are only 2 general types of paint, Alkyd (aka oil base) and Acrylic or Latex. These instructions will apply to all clear finishes and paints available to the average homeowner.

Solvents will be used to test the finish.

The first test uses Denatured Alcohol. Saturate a small area of a rag and gently rub the surface for a few seconds. If the finish is softened or removed it will be a water base paint, clear wood finish or Shellac. Shellac will be instantly dissolved while the water base finishes will remain tacky for a minute or so. If the finish wasn't affected by denatured alcohol move onto the next step.

Oil base paints won't be affected by Denatured Alcohol. If dealing with paint you now know what type it is. A little more effort is needed to identify clear wood finishes.

This test will use Lacquer Thinner. Saturate a small area of a rag and dab a small area. Lacquer will cloud but regains its gloss when the Lacquer Thinner has evaporated. If the surface crinkles or cracks after the thinner has evaporated then the finish is a Varnish or Polyurethane.

Paints and most clear finishes will require paint and varnish remover while paint stripping but with Shellac use Denatured Alcohol. Lacquer Thinner can be used on all lacquered surfaces. Now you can purchase the appropriate solvent or stripper and move on to the following steps.

Step 2) Prepare the Work Area

Protect surrounding areas and the floor. Stripping paint off wood is a messy job plus chemical strippers aren't selective about what it strips. If working indoors cover floors with a butyl coated drop cloth and furniture with lightweight plastic.

If possible work outside and in the shade. Still work over drop cloths and protect adjacent surfaces. The shade is very beneficial to you and the stripper.

Basic preparation for wood stripping consists of scraping all loose material and removing all dust. Any areas that won't be stripped will need to be masked with two layers of wide tape and paper. If you can't remove the item fully, mask all areas next to and around the wood that will be stripped. Protect all surfaces now or you will notice damage when the paint stripping is over.

Step 3) Applying the Paint Stripper

Use a disposable brush and apply the stripper thickly and in one direction only. Do not over brush; apply a thick coat using a single movement. Allow time for the paint stripper to work. The manufactures directions will include information on the "working time".

The main problem with paint stripping is not allowing enough time for the finish to be lifted. Allow the stripper to do the work so you don't have to. The temperature and direct sunlight can cause the solvent to evaporate to fast and dry out the paint stripper. You may have to apply additional coats. If working outside always try to be in the shade.

To control excessive evaporation cover the paint stripper with light weight plastic. The plastic can extend the working time by hours. Do not allow the stripper to dry completely on the surface.

When the finish begins to look wrinkled or you can expose raw wood while rubbing with steel wool, the finish is ready to be scraped off.

Step 4) Removing the Stripper and Loosened Finish

To remove the stripper and loosened finish without damaging the wood use a wide and smooth metal putty knife. File the corners round to avoid gouging the wood. Other tools that work very well for intricate areas and grooves are steel wool, an old toothbrush and small putty knife.

Carefully scrape away all of the loosened finish. Use fine steel wood to remove paint from the woods grain. After the first coat of stripper is removed you may find areas that retain some finish. Simply repeat the above methods.

Multiple layers of old oil base paint will require the application and scraping of multiple coats of paint stripper.

Step 5) Cleaning the Surface

After all the old finish has been removed clean the surface to remove any remaining stripper and neutralize the residue. Use a solution recommended by the manufacture. Usually water for water based strippers and mineral spirits for oil base strippers.

Start cleaning with 00 steel wool and the recommended solvent. Dip the steel wool into the solvent, squeeze out the excess solvent then stroke the surface in the direction of the grain. Keep repeating this procedure until all flakes of old paint and any residue is gone. Use a disposable bristle brush to clean intricate areas.

Some manufactures claim that cleaning isn't necessary after paint stripping. Experience has shown that it is always advisable to clean off all residue before continuing with the refinishing.