how to remove paint from upvc window frames

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

So, you taped up around your window frame to protect it while you painted the wall, stripped off the tape, and found, to your horror, that paint has bled under the tape and is now firmly adhered to your nice white uPVC frame.

Paint should be easy to remove when wet, but it takes on a new form that’s stubborn to shift once it’s dried. 

This guide will show you how to remove paint from uPVC window frames like a professional.

What to Consider Before Removing Paint from uPVC

Removing paint from uPVC window frames should, I know, be easy. However, there are a couple of factors to consider before choosing the best method for your situation:

  • What type of paint is it?
  • How long has the paint been there?

What Type of Paint are You Removing?

The typical types of paint you’ll come across are emulsion and gloss, but you may also find a wood stain, mainly if it’s outside.

Aerosol paint can also find its way onto your window frame, especially if you’ve used it as a stain block.

A school of thought says you should try to remove paint as soon as it lands on your uPVC frame, whereas others suggest you let it dry and then deal with it. Certainly, rubbing wet paint with a damp cloth could leave a thin layer that becomes difficult to remove compared to a thick dry blob.

Again, it comes down to the type of paint, so before I go through my favourite method of removing paint from uPVC, let’s explore the nature of the various types of paint.

Water-Based Paint

This category includes emulsion paint and some types of primer. As they’re water-based, these paints react well to a bowl of soapy water and a sponge.

Acrylic paints are also water-based, and when they dry, they leave a transparent polymer film that traps the coloured pigments. These paints require more than soapy water, so keep reading and follow our step-by-step instructions below.

Solvent-Based Paint

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

Solvent-based paint doesn’t readily adhere to plastic materials, so usually, they don’t need soaking, just a gentle scrape.

Wood Stain

One of the most challenging substances to remove is wood stain, which can be water-based or solvent-based. 

Although designed for wood, wood stain engrains itself into the surface when you spill it onto uPVC. Not as much as it does with wood, but enough to make life difficult.

Wood stain usually spreads thinly across the surface, so scraping it off is almost impossible without damaging the surface beneath.

What’s the Best Product for Removing Paint Stains on uPVC?

bar keepers friend logo white background

I’ve seen all kinds of recommendations on the Internet, such as acetone (as found in nail polish remover), denatured alcohol (ethanol or methylated spirits), and ammonia solution. These may be good with some paints but not others.

Also, certain chemicals harm plastic materials, and if they don’t react with the uPVC, they may damage the neoprene seals holding the glass in place.

I came across Bar Keepers Friend (BKF for short) several years ago, and I’ve never been without it. 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. It works great with all types of stains, and once you’ve finished this job, there are tons of uses for BKF around the house.

Health and Safety Measures

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

How To Remove Paint From UPVC Window Frames — Step-by-Step Instructions

Before you begin, make sure you have the following tools and materials:

Tools & 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)

Got all of the above? Great, let’s start!

Step 1: Prepare the 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, use the narrow edge of the credit card and try to remove a tiny spot. If it comes off easily, you may not have to go further. However, we recommend doing at least Step 2 to ensure a nice clean frame.

Water-based paint

Warm water applied with a kitchen towel or a sponge helps soften water-based paint. So try this technique before following the scraping instructions above and Step 2 below.

Step 2: Apply the Bar Keepers Friend  

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

Mix a small amount of the granules with water to make a thick paste. It’s better to work on a small area so you can see how well it works before moving on.

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: Consider a More Abrasive Approach (optional, tough stains only)

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

Sanding will most 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.

With tough stains such as wood stain, don’t try too hard to sand away the discolouration, or you’ll take too much of the surface away. In this case, sand enough to break through the topcoat and return to Step 2.

Step 4: Cleaning the Frame

This step is where you’ll put some shine back on your frame.

Any proprietary window cleaning agent will do, but thicker creams work better at restoring some sheen to your uPVC frame.

Apply the cream to the frame using a sponge and a lot of elbow grease. Work the cream into the treated area and beyond. The idea is to make it blend in and look natural.

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

How To Remove Paint From uPVC Window Frames — Final Thoughts

So, that’s it. The best way to remove paint from uPVC window frames is by using ordinary household products. I.e. Bar Keepers Friend

Check out our guide to stripping paint off wood for more paint removal tips.