How to Remove Polyurethane from Wood: Stripping Polyurethane

By MWB-Team •  Updated: 06/19/23 • 

Stripping a wood finish is always a messy affair. Polyurethane is one of the most durable finishes for wood. However, to refinish your furniture, floors, or other wood projects, you must learn how to strip polyurethane. In this article, we’ll take step by step on how to strip polyurethane and review some of the best polyurethane removers you can use.

Water-Based vs. Oil-Based Poly

Polyurethane is available in water-based and oil-based variants. Each of these has its own pros and cons that affect its durability, usage, appearance, and much more. Check out our oil-based vs. water-based polyurethane post for an in-depth understanding of these two types of polyurethane.

Both water-based and oil-based polyurethane form a hard protective film on the wood. Water-based polyurethane is generally thinner and only requires a smaller amount of stripper or sanding. Oil-based poly will require a stronger chemical stripper to break down the bonds in order to strip it successfully.

That said, you can employ different methods to strip water- and oil-based polyurethane. Below are some of the methods to successfully strip polyurethane.

How to Remove Polyurethane from Wood

1. Use Citristrip Stripping Gel

Citristrip is a natural paint stripper containing organic compounds from oranges or pine resin. It is less toxic than other paint strippers, but it also takes longer to strip a finish. Citristrip can effectively remove different finishes from wood like varnish, lacquer, polyurethane, shellac, latex, and many other oil-based paints.

Citristrip Stripping Gel
$22.05 ($0.69 / Fl Oz)

The Citristrip is a stripping gel that can easily strip different finishes from wood from polyurethane, varnish, lacquer, shellac, latex, and oil-based paints. Apply the stripper and let it sit for a few hours for the best results. It is easy to use and works well when stripping different finishes.

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How to Strip Poly with Citristrip

2. Use Lacquer Thinner

Lacquer thinner is a mixture of strong solvents and thinners in varying ratios from different manufacturers. The thinner is mostly used to thin lacquer and also to clean tools. However, because it is one of the strong thinners around, you can use lacquer thinner to strip polyurethane from wood.

Klean-Strip Lacquer Thinner
$27.38 ($0.21 / Fl Oz)

Lacquer thinners combine different solvents in different ratios. The Klean Strip Lacquer thinner is medium drying and great for thinning lacquer, washing brushes after applying lacquer, and stripping lacquer and other wood finishes. 

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How to Strip Polyurethane with Lacquer Thinner

3. Sanding Down The Polyurethane Film

If the polyurethane film is not too thick, sand it down using coarser grit sandpaper like #60 grit. The sandpaper will cut through the polyurethane finish and any stain down to the bare wood.

If you start with a #60 grit sandpaper, move to finer sandpaper as you sand through the finish until you get all of it from the wood. Once you’re done, you can reapply your desired wood finish. This method is great for smaller surfaces because sanding larger surfaces will take more effort.

4. Use a Cabinet Scraper

If you don’t want to use a chemical stripper or sandpaper, you can opt for a cabinet scraper. A cabinet scraper is a piece of steel that is sharpened and is used to shave or scrape off film finishes from wood. To use a cabinet scrapper, push or pull it on the wood’s surface to scrape off the finish.

There’s really no learning curve when using a cabinet scraper. However, your results will vary depending on how sharp your tool is and the hardness of the finish you’re scrapping off. Once you’ve removed most of the finish from the wood’s surface, you can lightly sand the wood to get a smoother surface.

Best Polyurethane Removers

If you want to remove polyurethane using chemical strippers, below are our best removers you can check out.

1. Citristrip Paint & Varnish Remover

Citristrip Stripping Gel
$22.05 ($0.69 / Fl Oz)

The Citristrip is a stripping gel that can easily strip different finishes from wood from polyurethane, varnish, lacquer, shellac, latex, and oil-based paints. Apply the stripper and let it sit for a few hours for the best results. It is easy to use and works well when stripping different finishes.

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2. Sunnyside Corporation Paint & Varnish Remover

Sunnyside Corporation Paint & Varnish
$44.32 ($22.16 / Count)

The sunnyside stripping gel works on latex and oil-based paints, shellac, lacquer, varnish, epoxy, and polyurethane finishes. For thicker finishes, let it soak into the finish for some time before scrapping it off. Overall, the stripper works great.

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07/14/2024 01:21 pm GMT

2. Klean Strip Premium Stripper

Klean Strip Premium Stripper
$33.50

The Klean Strip stripper works on different film finishes, such as epoxy, polyurethane, varnish, and paint. The product does its job very well, but use gloves and do it outside if possible.

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MWB-Team

Hello there! This is the Make Wood Better Team. Here, we share informative how-tos and guides focused on making wood better. Whether it's finishing wood, maintenance, or restoration, there's something on this website for you to learn and improve your skills.