How to polish glossy paint and remove scratches
Have you ever wondered how to restore shine to your once gleaming gloss paint bike? Maybe a little rubbing from the heel or a bad incline of the bike left a scratch on the surface of your paint?
In many cases, all it takes is a few basic supplies, a little elbow grease, and a bucket of patience. And to show you how, we hired Steve Gardner from Velocraft in Melbourne. Formerly known as Bikes by Steve, VeloCraft has quickly grown into one of Australia’s most sought-after bicycle paint shops. If you’ve ever seen the painting on a Prova or Bastion, you’ll understand why.
A quick warning: This is just a quick guide to the process and includes tips used to add a mirror-like glow to glossy painted frames. The same technique and process is applied to remove surface scratches and scuff marks. It is important to note that the instructions in this article do not apply to satin and matte finishes.
What you will need
Pneumatic or power tools allow for quick polishing, but everything can also be done by hand. Either way, you’ll need a well-lit area that will show imperfections.
If polishing by hand:
- 2000 and 3000 grit sandpaper
- The water
- Microfiber cloths
- Abrasive compound
- Machine polishing
If power polishing:
- 2000 grit sandpaper
- 3,000 sandpaper or 3,000 sandpaper disc and pneumatic paint pad
- The water
- Paint pad
- Paint cutting stamp (VeloCraft uses generic eBay stamps, sold in a pack)
- Paint polishing pad (as above)
- Abrasive compound
- Machine polishing
Polishing a frame in three steps
Polishing a freshly painted shiny frame is often done in three steps, each step using progressively finer and smoother abrasive material.
Those with an already painted frame can probably skip the first step. Likewise, if your paint is in good condition but the finish is dull, you may be able to skip step two as well.
First step: remove dust and skin
Most freshly painted frames will have a small amount of dust or blemishes on the surface. This first step is to use a light abrasive material to remove these imperfections.
Before you begin, Gardner will mask the ends and raised edges of the paint commonly seen around the head tube, cable ports, bottom bracket, dropouts, and the like. This protects those delicate areas where it is possible to accidentally wear out through the paint.
Next, Gardner uses 2000 grit sandpaper with water to gently remove any trapped dust or other imperfections. This is then followed by a finer 3000 grit wet sandpaper to remove the slight scratches caused by the 2000. Both of these grits are specialty grits – you won’t find them in a hardware store. Simply rub the area gently in a circular motion. Patience is the key to all stages.
Once this step is complete, wipe down the frame with a clean microfiber cloth.
Second step: Cutting the compound
This intermediate step begins to polish the paint by gently abrading the peaks and valleys in the paint and creating a smooth finish.
Here Gardner uses the Milwaukee M12 Paint Polishing Tool, something he describes as the “best thing I’ve ever bought.” This is used with a generic, inexpensive cutting pad and its preferred paint cutting compound – Farecla G3 Premium. You can achieve the same result with a microfiber cloth, cutting paste and a little elbow grease (especially a difficult job if the paint is not fresh, where the surface will have hardened).
Gardner applies a small amount of cutting compound to the pad, then rubs it along the surface of the frame he’s about to prepare – this reduces spattering of compound.
Gardner moves the tool in a steady, random motion along the painted surface, noting that spending too much time in a single area can create heat that can also damage old paints and potentially carbon frames. If you’re doing it by hand, do it in a circular motion.
This step should leave you with a smooth, even finish, but close examination in the light will reveal swirl marks from the cutting compound.
Wipe the frame with a clean microfiber cloth.
Third step: Polish
This last step is very similar to the previous one, but here Gardner switches to a fine polishing compound that removes swirl marks from the paint.
Gardner sticks to his beloved Milwaukee paint polish tool, but switches to a smoother, softer polishing pad and machine polish 05996 from 3M (aka swirl remover). This machine polishing liquid can also be used with a microfiber cloth.
The technique is the same as for the second step, using a regular random movement over the entire surface.
Wipe off and marvel at your own reflection.
The whole process of polishing a frame can take anywhere from an hour to five hours (an exhibition bike is likely to be closer to five hours).
Eliminate surface scratches
Surface scratches are common on bikes and can often be found on chainstays due to heel friction, on the top tube of a cleat, or on the steerer tube from which a bit of cable friction has developed. product. Assuming the scratch is only on the surface, then it is possible to make it disappear.
Removing surface scratches from a glossy paint follows the same process as described above, and in many ways it is not that different from the process of polishing rough aluminum and steel. . The goal is to remove the scratched coat of paint and gradually make that area smoother until it matches the surrounding paint.
To remove surface scratches, you need to remove the minimum amount of paint. For this, you will skip the wet sanding step.
First step: Cutting the compound
This is the same as described in step two above. You will need a cutting compound and a microfiber cloth. Power tools can also be used.
Here you will use firm pressure and rub the scratched area with a circular motion. Don’t just focus on the scratch, but rather the surrounding area as you are effectively trying to smooth the paint in that area and blend it in.
Repeat until the scratch fades or, ideally, is no longer visible. Wipe the area clean. You can call it good here, or take the Polish step.
Second step: polish
This step will remove the swirl marks and bring out a polish from the previous job. Repeat the instructions in step three above using a microfiber cloth and polish.
Rub the area until the scratch is gone and the surface has a consistent shine. The entire process of removing a surface scratch should only take 5-10 minutes.
Don’t forget to marvel at your manual labor when you’re done!
Thanks to Steve at VeloCraft to share his tips and techniques. You can see many of VeloCraft’s creations in our cover of the Handmade Bicycle Show Australia.