How to Remove Thompson’s Water Seal from Wood?

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Reviewed by
Eral Kadrija

Tony Adams

Thompson water sealer protects wood from water damage by penetrating it and sealing its pores. Since it penetrates the wood and is waterproof, it’s impossible to refinish the wood without removing it first. So, how to remove it?

To remove Thompson’s water sealer from wood, use a liquid chemical-based paint stripper. The liquid stripper will gradually penetrate the wood and dissolve the sealer from inside the wood.

You can also use acetone or denatured alcohol to remove it, or you can sand it off using 180-220-grit sandpaper.

Can You Remove Thompson’s Water Seal Without Removing Paint?

It’s possible to remove Thompson’s water seal without removing the paint underneath. To do this, you need to sand the water sealer off with 220-grit sandpaper. Immediately when you notice that you have completely removed it, you should stop sanding so you don’t sand off the paint underneath.

If you do this carefully enough, you won’t remove the paint. The worst scenario here is that you’ll remove or scratch the top layer of the paint, and you can always touch it up with a new coating.

You can also remove the sealer without removing the finish underneath by using a paste-like paint stripper. In this case, you’ll apply only a light coat of the paint stripper directly on the finish and leave for about 20 minutes.

After 20 minutes, you’ll strip the stripping compound and apply another light coat it. Then again, wait about 20 minutes before stripping it off. You’ll need to continue this cycle until all the sealer has been removed and only the paint underneath is left.

This method is more reserved for professionals because it takes some experience with paint strippers, especially chemical-based paint strippers to know just how much to apply without affecting the finish underneath.

However, in most cases, you’ll cause scars on the finish underneath or remove part of it. But, you can always touch it up with one or two fresh coats.

How To Remove Thompson’s Water Seal?

Thompson’s water sealer is a waterproof coating. Since it is waterproof, it is resistant to almost every paint removal liquid that you can try. This is because the liquid can’t penetrate its coating, so it won’t remove it.

However, there are a few methods and products you can use to do it:

1. Use a Liquid Chemical-Based Paint Stripper

Use a Liquid Chemical-Based Paint Stripper

Liquid chemical-based paint strippers contain active paint-removing chemicals, such as methylene chloride. The stripping liquid will penetrate the sealant coating and dissolve the particles. Once the particles are dissolved, the coating will liquefy and you can wipe it off.

For this method, you’ll need these tools and supplies:

  • A brand of liquid chemical-based paint stripper
  • A pair of work gloves
  • A paint scraper
  • Paintbrushes
  • Clean rags
  • Mineral spirits
  • A wire sponge

Here is a guide for this method:

  1. Wipe the finish with a clean rag to remove dirt and debris.
  2. Apply the paint stripper directly on the sealer – you can wipe on, pour on, or brush on the chemical-based paint stripper.
  3. Wait 30 minutes.
  4. After the stripper has dried, scrape it off with a plastic putty knife.
  5. Use a wire sponge over the wood to remove the leftover sealer.
  6. Wipe the surface with mineral spirits to neutralize the paint stripper chemical.
  7. Leave the surface to dry.

2. Sand it Off

Sand The Thompson Sealer Off Of The Wood

The idea here is to grind the abrasive side of the sandpaper against the finish. Doing this will gradually scratch off the sealer from the surface. If you are working on a large surface, it’s advised to sand using a portable sander.

For this method, you’ll need these:

  • 180-220 grit sandpaper
  • A vacuum or duster
  • A pair of gloves
  • Rags

Here is a guide for this method:

  1. Wipe the finish to remove dirt.
  2. Sand the finish off with 180-grit sandpaper.
  3. Keep sanding until all of the finish is removed.
  4. Finish the surface with 220-grit sandpaper.
  5. Remove dust and allow the wood to settle.

Tip: While sanding, always watch the wood to know if you have removed it. This helps you to prevent over-sanding the wood.

3. Use a Hairdryer and Acetone

Use a Hairdryer and Acetone

Acetone is a natural paint remover and will remove the sealant. However, you must sand the sealant glossy finish off the surface first. If you don’t, the acetone won’t be able to penetrate the sealant and remove it.

  • Acetone
  • A hairdryer
  • Rags
  • A paintbrush
  • A plastic putty knife
  • A nylon bag
  • A pair of gloves
  • A face mask

Here is a guide for this method:

  1. Wipe the wood with clean rags.
  2. Use a 220-grit sandpaper to sand off the glossy finish of the sealant.
  3. Clean the surface
  4. Pour some acetone into a clean bowl and soak a rag into the bowl.
  5. Use the dampened rag to wipe the finish repeatedly.
  6. Wait 20 minutes.
  7. After 20 minutes, scrape off the sealant.
  8. Re-apply acetone for leftonves.
  9. Clean the wood with warm water and a clean rag.
  10. Leave the wood to dry.
Tony Adams

Tony Adams

Woodworker, Interior and Exterior Painter, Flooring Specialist

Tony is a professional painter and an author of DIY Geeks. Tony has completed over 1,000 painting projects for his clients. It's safe to say he knows what he Is talking about.

Eral Kadrija

Eral Kadrija

Lead Editor, Home Renovator

Eral has a passion for home renovation and repair. Over the years, he has bought, renovated, and sold 7 old homes. Using his experience from different DIY projects he created DIY Geeks.

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