Light scratches on powder-coated aluminium frames can usually be buffed out with a mild, non-abrasive cutting compound, while deeper scratches that go through the coating need filling and a colour-matched touch-up paint. Only bare, uncoated aluminium should ever be sanded. Aluminium window frames have become incredibly popular in recent years because they offer a variety of benefits over frames made from other materials.
However, while aluminium window frames are incredibly durable, they are not exempt from scratches. This is likely why you'll want to know how to remove them!
In this guide, we'll explain a few different ways that you can remove scratches from aluminium windows. We also offer a variety of other guides here at Aluminium Living, such as how to remove cement from aluminium windows and how to clean mould off aluminium window frames.
How Do You Remove Scratches From Aluminium Window Frames?
Clean the frame, then check how deep the scratch is. Marks that sit in the surface of the coating can be polished out with a mild cutting compound; scratches that reach bare metal need filling if deep, then a colour-matched touch-up pen or paint. Sanding is only suitable for bare, uncoated aluminium. A quick test: if your fingernail does not catch in the scratch, it is usually only surface-deep.
As we have mentioned above, aluminium window frames are affordable, durable, and low-maintenance window frame options.
However, they can pick up scratches like any other window frame material does, so before you repair scratches, assess how deep they are to decide the most suitable fix. This is why we have provided ways to fix this problem below.
Prompt attention can prevent costly replacement, reduce the need for frame replacement, and help maintain property value.
For severe damage, professional repair can save 50% to 80% compared to replacements while helping preserve the structural integrity of the frames.
Can You Sand Scratches Out of Aluminium Frames?
Only if the frame is bare, unfinished aluminium. Use fine wet-and-dry paper, starting around 400 to 800 grit and working up to 1500 grit or finer, sanding with the grain before polishing. Never sand powder-coated or anodised frames unless you plan to refinish them, as you will cut straight through the factory coating.
If you have a plain aluminium window frame, this method is only suitable for small scratches on a plain metal surface.
Before sanding, remove dirt and dust with a soft cloth rather than abrasive tools to avoid scratching the frame further and help prevent damage. For very minor abrasions, a high-quality wax-based filler can be used before a light wipe and sanding.
If there is only one small scratch bothering you, then you should not use a sander. You can use a piece of sandpaper and some elbow grease until all of the scratches are gone.
If your window has many scratches, then you can use a sander, but you should be careful not to create more damage and choose the right tools. This sanding approach is not suitable for powder coated finishes or heavily damaged frames.
How Do You Touch Up Scratched Powder-Coated Frames?
Clean and degrease the scratch, then apply a colour-matched touch-up pen or paint in thin coats, letting each one dry. Most manufacturers can supply a RAL-matched kit for your frame colour. Feather the edges so the repair blends in, and finish with a light polish once the paint has fully cured.
If your window frame comes with either a smooth glossy finish or a matte finish, you might be able to use touch-up products or Dulux repair kits to hide scratches on painted aluminium window frames.
You can often use some acrylic paint to do some touch-ups on matte finishes if you can find it in a colour that matches your window frame and suits the damaged area.
If your frame has more of a glossy look, then automotive paint or spray paint will be a better option, as long as it matches the colour of your frame. For a 100% colour match on the repaired area, professional restoration is usually the better choice.
You should use this paint sparingly, applying it in thin, even coats for best results, then check the repaired area so it blends in and the finish looks right. Alternatively, you could repaint your window frame entirely if you think they look a little old and want a job that will deliver results.
How Do You Repair Deep Scratches in Aluminium Frames?
Deep scratches that expose bare metal should be filled with a metal-compatible filler, sanded flush once dry, primed and painted with a colour-matched finish. For large gouges or many damaged frames, an on-site powder coat or respray specialist will give a far better, longer-lasting match than DIY touch-ups.
If your aluminium window frame has deep scratches in it that have gone through the protective coating and caused deeper surface damage, then you may need to opt for a different solution.
You can repair these scratches using a high-quality filler, which can also help with minor dents, but more severe damage is best left to expert technicians using suitable repair techniques as part of the repair process. Once you have placed your filler on the scratches and it has dried, it can be sanded and painted to look like the rest of your frame.
Prompt professional repair can restore the frame to its former glory, help prevent oxidation and corrosion in coastal areas, and is often completed in 1 to 3 hours per frame.
How Do You Polish Out Light Scratches?
Wash the frame with warm soapy water, dry it, then work a small amount of mild cutting compound or metal polish into the scratch with a soft microfibre cloth using small circular movements. Wipe off the residue, check the result and repeat gently if needed. Always test on a hidden area first, and stop as soon as the mark fades so you do not dull the surrounding finish.
- Clean the area so grit is not rubbed into the coating.
- Apply a pea-sized amount of compound to a microfibre cloth.
- Polish with light pressure in small circles.
- Buff off with a clean cloth and inspect in daylight.
- Finish with a car wax or protective spray to restore sheen.
What Should You Avoid When Removing Scratches?
Avoid scouring pads, wire wool, bleach and solvent-based cleaners, as these damage powder coating and can leave dull or shiny patches. Do not sand coated frames, do not use household gloss paint, and do not work in direct sunlight, which makes polish and paint dry unevenly. If your frames are anodised rather than powder coated, use only gentle polishes, as anodising cannot be touched up with paint as easily.
How Can You Prevent Scratches on Aluminium Frames?
Clean frames every few months with a soft cloth and mild detergent, protect them with masking film during building work, and apply a non-abrasive wax once or twice a year. Building work is the biggest cause of damage, so cover frames before plastering or rendering; our guide to removing cement from aluminium windows covers what to do if splashes land on them. The factory powder coating applied when aluminium windows are manufactured is tough, but it lasts longest with gentle care. The same advice applies to aluminium bifold doors and sliding doors.
Aluminium Frame Scratch Repair FAQs
How do you clean aluminium?
If you want to clean your aluminium window frames, regular cleaning every 3 to 6 months is essential as part of regular maintenance to prevent damage and avoid scratching the finish. Use a soft brush with warm water and a mild detergent to remove dirt from the frame, then rinse and wipe dry with a soft cloth. Avoid abrasive tools, bleach, and other harsh chemicals, and clear debris from each aluminium door track to maintain drainage.
Can you repaint aluminium window frames?
Yes, you can easily repaint an aluminium window frame. If you think there are too many scratches on your frames, then you can cover the glass using some newspaper and sticky tape.
You can then apply spray paint in thin coats after proper masking, remove the newspaper and tape, and leave them to dry. DIY attempts often look patchy, so professional repair is a better choice when you want to replace a factory finish as closely as possible.
Which coating is the best for aluminium windows?
A powder coating can increase the durability of your window frames significantly. Powder coated finishes are different from other options, and the best choice depends on the metal surface and how durable you need it to be. A protective coating also helps prevent scratches, corrosion, and other damage, and expert advice is useful if you want the most suitable finish.
Can you use T-Cut on aluminium window frames?
Yes, a mild car cutting compound such as T-Cut can remove light surface marks from smooth powder-coated aluminium if you use it gently with a soft cloth. Test it on a hidden area first, and avoid it on textured or anodised finishes, where it can leave noticeable shiny patches.
Can scratched aluminium frames corrode?
Aluminium does not rust like steel, but scratches that reach bare metal can develop white, powdery oxidation and filiform corrosion that creeps under the coating, especially near the coast. Seal any scratch that exposes bare metal promptly with primer and touch-up paint.
Is it worth repairing scratches or replacing the frame?
Repairing is almost always the better value for cosmetic scratches, as touch-up kits and professional resprays cost a fraction of new frames. Replacement only makes sense if the frame is also bent, leaking or failing thermally. If you are weighing up new windows, see our guide to how much aluminium windows cost.
