How to remove polyurethane from wood the easy way

When you need to protect the wood from chemicals, water, and other causes of deterioration, polyurethane is one of the most known and widely used finishes. 

Sometimes there is a need for removing polyurethane from the wood if you want to stain or repair wood furniture. This step-by-step guide will help you to go through this process

Things you need to know about polyurethane

Polyurethane is a liquid coating that forms a protective, durable, extra-long-lasting layer on wood surfaces. It is a liquid plastic that brings up a beautiful look in natural wood grain, or shiny glossy finish of painted wood while protecting from any damage.

It preserves and prolongs the wood’s life for years. It also can be quite challenging to remove polyurethane from wood.

What are the types of polyurethane?

There are two formula types of polyurethane: water based polyurethane and oil-based polyurethane.

Water-based polyurethane

The main difference between water-based polyurethane and oil-based polyurethane is in how they are made.

There are some water based polyurethane strippers on the market, that are more resilient than others.

Oil-based polyurethane

What removes polyurethane finish?

There are a few ways to remove polyurethane from wood:

1. Using chemical strippers
2. Using homemade polyurethane remover
3. Sanding the wood surface down to remove polyurethane

Let’s look into each way in detail.

Using chemical strippers

The fastest way to remove polyurethane from wood is to use a special chemical polyurethane stripper. How to choose the right one among the variety offered at a hardware store? Our recommendations will help you to make the right choice.

1.     Sunnyside Corporation paint and varnish 2-minute remover

• The fastest and a more affordable stripper
• Acting fast on multiple layers of polyurethane in a single application
• Perfect for use on vertical surfaces
• Can be used on different types of surfaces such as polyurethane, paints, epoxy, varnish and shellac
• One container covers a surface up to one hundred square feet

2.     Sunnyside Corporation Hi-Speed ready-to-strip paint and varnish remover

• More convenient and premium quality stripper
• Comes in a spray bottle, no need to use paintbrushes
• Has a no-drip formula, which makes it ideal for vertical surfaces
• Rapid activation time
• Environmentally friendly with low odour

3.     Dumond Smart Strip advanced paint remover

• The most environment-friendly stripper with the overall best performance
• Safe to use near plants or animals as it has no VOC
• Biodegradable
• Doesn’t have any harsh chemicals in its formula including a dangerous methylene chloride
• Ph-neutral
• Effective in the removal of multiple layers of paint

How do you remove polyurethane from wood without sanding?

The process of sanding is quite laborious and creates a lot of dust, so another option for removing a polyurethane layer is to use a special product – chemical based paint strippers. Once you have chosen the product you will be using, follow the guide below.

Things you have to consider before starting:

1.     Tools necessary for the project

• Paint brush
• Wire brush
• Plastic scraper

2.     Personal protective equipment

• Thick rubber gloves. Polyurethane remover can be quite toxic, gloves will protect your hands.
• Eye protection – safety goggles. To prevent the irritation of your eyes caused by harsh solvents.
• Face mask – KN95. To prevent the irritation of your throat or lungs.
• Work clothes – a long sleeve shirt and long pants. Choosing the proper gear will minimize the risk of exposure to harmful chemicals.

3.     Preparing the area you are going to be working in

• It is important to work in a well ventilated area as the chemicals you are going to use are quite strong
• If there is no ventilation, open all the windows and doors and place two fans blowing inside and outside of the room
• The floor and any furniture must be covered up with a cloth or some plastic sheeting

Any polyurethane stripper that contains methylene chloride can only be used if you fully understand how to protect yourself by wearing proper gear.

How to remove polyurethane from wood

The process of removing polyurethane is pretty much the same whether it is furniture, doors or wooden floors.

Using homemade varnish removal mixture

There is an option of removing polyurethane from wood without using harsh solvents. You can make a homemade mixture using baking soda, water, cornstarch and other ingredients.

Follow the recipe:

1. Boil four cups of water
2. Mix half a cup of cold water with one cup of cornstarch
3. Add ¾ cup of baking soda and 1 tablespoon vinegar into the container with 4 cups of boiled water
4. Stir thoroughly
5. Add to cold water mixed with cornstarch

The mixture is ready to be used.

How does vinegar remove polyurethane from wood?

The process is quite straightforward but can be time-consuming. Follow the steps:

1. Apply the homemade mixture onto the wood surface, using a paintbrush
2. Wait for a few minutes to allow the mixture to soak through the layer of polyurethane
3. Scrub the wood surface using a wire brush or a stripping pad. Apply some pressure when scrubbing the polyurethane layer
4. Sand the wooden surface down using different grit sandpaper starting with 60 grit for rough spots and moving to 120 grit until the wood surface becomes smooth
5. Wipe the surface with a dry clean cloth

Can you sand polyurethane off wood?

Although it is possible to sand the polyurethane finish off wood, it is time-consuming and not always easy and smooth. If this is the option you want to try out, follow these steps:

1. Start with heavy grit sandpaper or fine steel wool to shorten the work time
2. Once you remove most of the polyurethane from the wood, use fine grit sandpaper to smooth the surface
3. It is important to be gentle while sanding in the wood grain direction to avoid any grit scratches.
4. Clean the surface after removing the polyurethane

How do you remove polyurethane from your skin?

While removing polyurethane using a chemical stripper, there is a chance that some of it will get onto your skin. It is important to know how to remove polyurethane because of the dangerous and harmful chemicals in its formula that causes skin irritation and inflammation.

There are different options you can try, depending on the actual type of polyurethane.

1.     Vegetable oil, peanut butter

• Take a cotton pad soaked in olive oil
• Gently rub it into the skin which needs to be cleaned
• Using a dry cloth remove polyurethane

2.     Mineral spirits or denatured alcohol

Use this option cautiously as it can irritate your skin even more. It does have an advantage though – it works faster for removing polyurethane.

What to do with bare wood after removing polyurethane

Once you learned how to remove polyurethane from wood, you have to know what to do with bare wood and how to take care of it.

1.     Clean the wood

Once the protective layer is gone, you need to clean the wood using some wood cleaner. Wipe the area with warm water and dry it with a cloth.

2.     Use an after-wash solvent

If there is any polyurethane left on the wood surfaces, you might want to use a special product that will remove any remnants of the polyurethane or any leftover paint stripper.

• Use a piece of paper towel soaked in a solvent
• Rub the wood surface
• Remove polyurethane from wood

How to remove polyurethane from wood floors

Polyurethane creates a strong protective layer on the wooden floors preventing any destruction.

1.     You start with choosing the appropriate paint strippers

If you go with a chemical stripper, make sure the area you are working in is well-ventilated. It shouldn’t be too hot or too cold in it. Use fans to create extra airflow to get rid of fumes that the chemical stripper might emit.

If you opt for the water-based remover for stripping polyurethane off the wooden floors, bear in mind that it will take sufficiently longer, but at the same time less harmful for you and the environment.

2.     Make sure you wear protective equipment

It is very important to protect your eyes with safety goggles, and your face with a mask and to wear appropriate clothing that covers your skin, including rubber gloves.

3.     Prepare the room you are going to be working in

Remove all the objects from the room, including furniture, carpets and any other things that can be damaged in the process.

4.     Stripping polyurethane off the wooden floors

• It is more convenient to apply a stripper with a paintbrush if the area you are working with is vast
• If you are using a chemical based stripper, the waiting time for the product to start working will be just 10 minutes
• If you are using water based strippers, the process of dissolution of the polyurethane might take up to 6 hours or even longer
• Once the polyurethane starts bubbling and peeling off, scrape it off the floor surface using a plastic or a metal scrapper
• If there is some polyurethane left on the floors after scraping, you will need to apply another layer of the polyurethane remover. Repeat the whole process again.

5.     Sanding the floors down

The last step is to give the wooden floors their natural look back. Sand the wooden surface down using different grit sandpaper or steel wool and wipe the dust off the floor using a clean cloth.

Frequently Asked Questions (FAQ)

To summarise

Removing polyurethane off the wood can be quite challenging. This article helps you to go through the process step by step.

You learn a lot about polyurethane itself, its consistency, about the products that can help you to remove it from wood. Follow the instructions on how to do it and you will achieve great results safely.

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