Frame refinishing
 

I didn't see a refinish or restoration forum here, only frame building, so I thought I would post this here. If it is in the wrong section, please move this, mods.

I have a five year old 7005 Kinesis aluminum frame that has gotten pretty nicked and scratched up over the years (gotta love black). The frame is still solid with no cracks and I was considering repainting it. What is the best way to go about this? Is there certain paint strippers I should stay away from? Should I just scotch brite the old paint off?

Also, I might want to keep the frame a naked, raw, silver finish - is aluminum safe to leave unfinished or is there something I need to put on it once the paint is removed?

Thanks for the help.

Aluminum must have a finish or it will oxidize. Your basic options are paint, powdercoat, and anodize. If you want one solid color and durability, powdercoat is the way to go. The frame will have to be completely stripped. Many powdercoaters will do this for an additional fee. Make sure you work with a powder coater who knows bike frames, not just has done a few. You don't want powdercoat inside places like the seat tube, bottom bracket, or head tube or clogging threaded holes like bottle cage or fender mounts. A good powdercoater who has good knowledge of bikes knows how to give you a frame that is ready for the build.

Paint is another option, but unless the bike is a beater, stay away from rattle cans. Automotive paints like Imron or two-part urethanes are much tougher but require specialized knowledge, equipment, and a controlled environment to apply. The painted frame will spend some time in a heated, humidity-controlled room where it will be "baked" speeding the hardening process. At room temperature, many paints can take days or weeks to reach full hardness. Some automotive body shops will do bike frames, usually the small independent guys. The big shops don't want anything to do with them as they are particularly difficult to do because of all the nooks and crannies, require the use of a detail gun, and don't bring in the money that a vehicle refinish will. If you have a friend with a body shop, sometimes you can get them to shoot a frame with the leftovers from an automotive refinish if you are willing to leave the prepped and primed frame with them until they get the right time to do it. You might have to pick from just a few colors based on recent or pending jobs. If you want your frame silver, you can have it blasted with walnut shell to give it a satin finish then clear coat it. Clear coat over polished aluminum tends to scratch and flake as there is no tooth, nor primer to help hold it to the metal.

Anodizing can leave aluminum silver or can add translucent color. Finding a shop to do it is the biggest problem most of the time and it can be expensive.

Painting a frame is easy. Doing a nice looking and durable job is A LOT more involved. As a start any paint you can use (given that you have to ask and don't do painting already) won't be as durable as the factory job. Step one is removing the original paint. You can mechanically remove or chemically. On the large smooth sections (the majority of the tube) you can sand or scrape off paint pretty quickly. Around the joints/welds you'd want to bead blast or use chemicals. Depending on the factory paint the common StripEze might not be aggressive enough, aircraft stripper is stronger but more $. Once you have the paint off then if you repaint you need to prep the surface. That's both making the surface smooth (file marks, scrapes, dings, nicks. Since this is an Alu frame stress risers are of paticular concerns), clean of grime and oils, etching it to allow the primer to get a good "bite" then primimg. Alu likes it's own primer as does many paints. make sure that the primer is compatible with both. Then you apply the actual color coats. Maybe sanding between primer or color coats to smoothen out things, like runs. Decals come next with a clear series of coats last. Then let the paint cure, heat helps to a point.


This is a messy and time consuming job to do even with rattle cans. And retail bought paint is pretty fragile. You might be better served by finding a painting service to do this. Places that do motorcycles, ATVs or indrustral equipment are where i'd look first. Auto painters rearly do good and motivated bike work. You'll find that powder coating is cheaper and usually cruder looking. Many powder coaters don't bother with primers or undercoats so do your homework here. Quality wet paint using the proper primers, colors and clears with good preperation steps is expensive, for a reason.

Leaving the Alu raw looks cool for a while but the surface will show corrosion in time. Sweat and road spray will dot it. You could have it anodized but the welds will take the process differently then the tubes.

Consider if this bike is worth this. If not then a quick and light sanding to not remove but etch the original paint (and sand through the decals removing their presence) then painting over that might be the easiest and still retaining the stock protection. Andy.

Thanks for the detailed replies, guys - much appreciated! I figured it would be alot of work but I really had no idea of all that was involved, nor the different choices I had. From the sounds of things, and considering the cost of the bike, I think the repaint over preped, old original paint might be my best option. I don't know the quality of Kinesis aluminum, but I know from the price I paid for the bike complete, it is not like a precious steel or TI frame. Thanks for the help and advice.