how to remove paint from upvc window frames

How To Remove Paint From uPVC Window Frames (DIY Guide)

During a recent decorating project, I diligently taped around window frames to protect them from paint. However, when I stripped off the tape, I found that the paint had bled underneath and firmly adhered to my white uPVC frames.

I knew from years of experience that paint is easy to remove when wet, but it takes on a new form that’s stubborn to shift once it’s dried.

In this DIY guide, I share the process I use to remove dried paint from uPVC window frames.

What To Consider Before Removing Paint From uPVC

Removing paint from uPVC window frames should be straightforward, but there are two crucial factors to consider before choosing the best method.

  • Drying Time — How long has the paint been there, and should you let it dry?
  • Type of Paint — Water-based or Solvent-based paint

Drying Time

A school of thought says you should try to remove paint as soon as it lands on your uPVC frame. Others suggest letting it dry, as rubbing wet paint with a damp cloth can leave a thin layer that becomes difficult to remove.

This decision comes down to the type of paint, so before I go through my favourite removal method, let’s explore the nature of various paints.

Note: The instructions below explain how to remove dried paint from uPVC window frames, not wet paint.

Type of Paint

There are many different types of paint, but they all fit into one of two categories — Water-based or Solvent-based.

Water-Based Paint

This category includes emulsion, vinyl and chalk paints. As they’re water-based, these paints react well to soapy water and a sponge.

Acrylic paint is also water-based, but when dry, it leaves a transparent polymer film that traps coloured pigments. This paint needs more than soapy water to remove, so please follow our instructions below when dealing with acrylic.

Solvent-Based Paint

Often referred to as oil-based paint, these paints have high levels of organic compounds, providing a more durable finish than water-based paint. 

Solvent-based paint doesn’t readily adhere to plastic materials. Therefore, these paints don’t need soaking, only a gentle scrape.

Best Product For Removing Paint From uPVC

bar keepers friend logo white background

I’ve tested all kinds of recommendations, such as acetone (as found in nail polish remover), denatured alcohol (ethanol or methylated spirits), and ammonia solution. These options may be effective with some paints, but not the paint I used. Furthermore, some contain chemicals that harm uPVC and the neoprene seals holding the glass in place.

I came across Bar Keepers Friend (BKF for short) several years ago, and it’s never let me down. It works great with all types of stains and has many other uses around the house. BFK is available as a spray, but I prefer the original powdered form. 

The main ingredient of BKF is oxalic acid, an organic plant-based compound that removes stains on all surfaces. Oxalic acid is slightly abrasive in that it etches the surface, but the effect is negligible on uPVC.

Note: Bar Keepers Friend is a mild acid, so wear gloves and avoid contact with your eyes and skin.

Tools & Materials

Before you begin, ensure you have the following tools and materials:


  • Kitchen roll
  • A sponge
  • A soft cloth
  • An old toothbrush
  • 220–320 grit sandpaper (optional, tough stains only)


  • Soapy water in a bucket
  • Butyl or latex gloves
  • Bar Keepers Friend (other oxalic acid products are available)
  • Window cleaning agent (Windolene or similar)

How To Remove Paint From uPVC Window Frames

The instructions below show you how to remove dried paint from uPVC window frames.

Step 1. Prepare Surface

Before preparing the surface area, you must first determine whether you’re dealing with solvent or water-based paint.

Solvent-based Paint

You can often remove Solvent-based paint by scraping it off the surface. Old credit cards are handy for this job — they’re rigid but not sharp enough to damage the uPVC. 

To begin with, try using the credit card’s narrow edge to remove a tiny spot. If it comes off easily, you can use this technique to remove all the paint. However, we still recommend following at least Step 2 to ensure an immaculate uPVC frame.

Water-based paint

Applying warm water with a kitchen towel or sponge helps soften water-based paint, so try this technique before following the scraping instructions above and Step 2 below.

Step 2. Apply Bar Keepers Friend  

It’s time for the BKF! Remember, you need gloves for this step.

  1. Mix a small amount of the granules with water to make a thick paste.
  2. Rub the paste into the stain using an old toothbrush. Apply gentle pressure at first but increase the pressure as you go. You can also use a sponge for this part.

Step 3. Lightly Sand Tough Stains (Optional)

If BKF doesn’t work, use fine-grit sandpaper to erase the paint gently. 

Note: Light sanding will likely remove some of the frame’s sheen, but it looks less unsightly than the paint splash, especially if it’s a highly contrasting colour.

Step 4. Clean Frame

Any proprietary window cleaning agent will work, but thicker creams are better at restoring sheen to uPVC frames.

Apply the cream to the frame using a sponge and a lot of elbow grease. Work it into the treated area and beyond, ensuring the whole surface area has a consistent finish.

On completion, wipe the frame with fresh, soapy water and a soft cloth. Dry off using a sheet of kitchen roll.

Final Thoughts

After many hours of testing, I discovered the best way to remove paint from uPVC window frames is by using Bar Keepers Friend. It works every time and is super handy for other jobs such as cleaning bathrooms, kitchens, rusty tools and BBQs.