This is a bit outside the normal "bicycle mechanics" scope of this forum, but I didn't quite know where else it might fit...

My Kona Unit was used by the previous owner as a dirt bike, and has the normal amount of scuffs & scratches in the paint. I don't want to strip and repaint it - the frame isn't in that bad a condition. I would, however, like for it to look somewhat spiffier than it currently does.

I see two potential paths to restore the paint without stripping the frame. The first (and easiest) involves using some Testors model paint and a fine tipped artists brush to cover the existing scrapes and scuffs. This wouldn't leave a smooth surface, but it would fill the scuffs and make them less visible.

The second involves masking off the rest of the bike and (after roughing up the surface of the existing paint for adhesion) using a spray can to cover specific areas of the frame.

Are there other alternatives I've not considered? If not, which of the two methods would yield the best finish? Would it be worthwhile to brush the scratches first, sand them smooth with the existing paint, and then clear-coat with a spray can to hide the edges?

I'm in unknown waters here...

Thanks - FH

Fingernail polish is available in a dizzying array of colors; I have generally been able to find a very close match when I needed it. The store personnel are surprisingly accommodating of requests to bring the bike in and do some color matching, if you ask nicely. Surprisingly, whites are the toughest colors to match; there are more shades of white than any other color.

I have lately gotten some touch-up for my car Dr. ColorChip Automotive Paint Chip Repair Kit - Dr. ColorChip: Automotive Paint Chip Repair Systems which uses a solvent on a firm cloth to level out the touched-up areas. It works surprisingly well; if you could find a matching color you should be in business. I would imagine that coarse buffing compound would similarly level your touch-up work.

Testors model paints come in a bunch of colors and in sets of many colors. If you are careful you can mix the colors to get the color you need. Roger

I don't have any advice on the best paint but if you want to prep a bunch of small dings easily get one of these spot sanding pens. https://www.amazon.com/s/?ie=UTF8&key...l_8gfay764ml_e By just rotating the pen between your fingers you can precisely remove paint and rust in a very small area and works fast. For bigger areas just use a back and forth movement. Oh, and wear rubber/latex gloves and eye protection. These use very thin glass fibers which break off as you use the pen and can easily get stuck in fingers and eyes, not good.

Brush in cap touch up paint Bottle of same color. Often Asian factories include them but they dont go out the door with the bike

Ask the LBS if they have a bin of the little bottles saved ..

If you contact Kona customer service, they might be able to provide or sell you some touch-up paint in an exact match. I have used the Testors paint myself and mixed reasonable color matches, as long as you don't look to closely. I have yet to perfect the art of painting touch-ups so they aren't "bumpier" than the surrounding paint.

The spot touch up will give you the best results, but it's more involved than you described. What you want to do is repeatedly apply paint to the chips and scratches (allowing each coat to fully dry) until it builds up to just slightly higher than the surrounding painted/powder coated surface. Then you sand it down flush using some fine wet-dry sandpaper affixed to a small block of wood. Once you get it flush, lightly sand with some ultra-fine wet-dry and then polish with some automotive polishing compound. If your color match is good, the touched up areas will be nearly indistinguishable. However, be aware that this is a time consuming and labor intensive process.

Stay away from rattle-cans (unless you *really* know what you're doing -- in which case you wouldn't be asking). Even if you get lucky enough that it doesn't look like crap initially, within a year it will likely look worse than what you started with.

The best solution is just ride it as-is. The patina adds to the character of the bike. A mountain bike without chips and scratches is a sign the owner has never used it to its full potential If the chips/scratches are down to bare steel, treat any surface rust and then periodically wax the frame with some inexpensive automotive spray wax to keep new rust at bay.

I have bought a few used bikes/frames. Sometimes I agree with kopsis, don't add paint, just protect. Mostly I prefer to touch-up, and I use a technique similar to the method he posted above. If I have dulled a significant area by sanding, I mask it off and spray a few coats of clear Lacquer and then use ultra fine wet or dry sandpaper (1200 or 2000) and car buffing compound to blend the surfaces.

The stays, seat cluster, fork and part of the top tube on this bike have been resprayed to repair rusty chips and scratches. A chain wrapped around the seat post had really chewed it up. I spent countless hours prepping the surface, priming the bare metal with etching primer spraying and then sanding with high build primer and then white primer before spraying the white acrylic enamel. then I had to rub it out with two grades of compound to get the gloss even. It was all worth it to me because the repairs are almost undetectable, but I don't ever want to do it again.

A big mistake beginning painters make is getting the surface too smooth. The primer won't adhere well to a too-smooth surface. You want to leave scratches that are just deep enough to be filled by the primer. That calls for about 320 paper.

+1 on nail polish.

I've had good luck painting with a toothpick! Just use the sharp end to deposit paint in the scratch or nick. Then, polish smooth after it is good and dry.

Let your enamel cure for a couple of weeks and then you can carefully wet sand with 1000 and 1200 gt sandpaper (available at any automotive store that sell finishing supplies) on a flexible backer pad. Work slowly, trying to just remove the high spots. Finish with a buffing/polishing compound to restore the shine. Lightly polish the surrounding tubing so that you don't have one spot shinier than the rest and finish with an automotive wax. If you work carefully, even paint that doesn't match perfectly will blend into the surrounding paint enough that it won't be obvious from normal viewing distance of a few feet.

Even if your enamel feels bone dry, don't rush it, give it a couple weeks to cure, longer in cool/damp weather. If it is really hot, dry and sunny you can maybe go a little sooner.

Thanks - I don't need perfection, so some Testors paint should suffice. The black frame should be easy to match.

+2. Even comes with its own brush.

Just another thought for touching up: my criterion is how it looks from about 5-6 feet away. You really don't have to be that close in color. Certainly, various shades of "black" would do (and there's a million shades of black... look at an auto parts store's touch up paint section).

I touched up the black on my Sr Semi Pro with model paint with good results. One thing I would recommend is to mask off the frame around the chip/ scratch as closely as you can to the affected area using 3m blue tape. Then when you sand down the rusted ares you won't sand a larger area than necessary. I like to sand , then put a dab of naval jelly on the spot to clean off the rust/ follow with a rust inhibitive primer ( Rustoleum) then color with paint brushed on with a fine artists brush . Pull the tape off then re tape back about a quarter inch and then wet sand the patch with 1000 grit wet and dry paper. Let dry thoroughly. Remove the tape and go over area with white polishing compound applied lightly and see how it looks. With a black frame it should pass the 3 ft test.

If the frame is black, (i'd recommend this for most colors but black in particular), One Shot Lettering Enamel. Look around and you can even find that in a half pint I believe. Self Leveling, high gloss, excellent adhesion, no sanding before or after. Just fill the chip hole with it facing up, (defect level), wait overnight, (12hrs. min.), and done. May be off a tone, but the repair is easy and neat. Use a quality brush, and a light pre-application of rust preventative primer if there appears to be rust in the chipped area. The lead in the paint, (yep Still Lead Based), would likely take care of the corrosion anyway. Easy repair with great results, and no surrounding areas to blend. It should flow to the edge of the chip and stop like filling a swimming pool.

+1 on the toothpick and Testors paint.

There's "perfect match" and there's "not exactly". "Not exactly" usually looks like crap because it draws your attention to the paint chip.

Fingernail polish comes in a LOT of colors so, if you have a red or a black bike, you have a decent shot for a good match. Testors has many fewer colors but, if you are a good color mixer, that might work for you.

I generally just use clear fingernail polish. I don't know how much metal protection it provides, but it makes me feel better.

If you have a lot of nicks or a big area to do, my advice is to have the whole frame powder coated. I've not had good results using a rattle can over existing paint.

I bet you made some nice plastic models. I used to mix them. Humbrol seemed more durable.

I also like Humbrol enamels better. They are thicker, and take longer to dry, though. A good, clean lacquer thinner is a necessity to mix the paint thinner.

I would add a caveat to the Nail Polish - I've had good luck finding strange colour matches with nail polish as well, but sometimes it doesn't age well - especially exposed to bright sun. I have one bike in particular that I found a perfect match for the weird purple paint - when applied.

Two months later it's an entirely different colour, and clearly visible. Makes for an interesting effect on a beater, but maybe not what you're looking for!