I have a frame that I'd like to sell. To avoid it being stolen, I covered it in tape and spray paint. I rode it for 5 years in London and this worked very successfully. However, I'd like to make it look nice again.
The original glossy paintwork seems to be well preserved under the matte paint I put on. Is there a way for me to strip off this layer while leaving what's underneath?
Here is the best-case scenario:
the finish you applied is a single-component lacquer or enamel of some type which dries purely by evaporation of the solvents, not by a chemical reaction. No "hardener" was added to this when applying, and it's not a type which reacts with humidity or oxygen in order to further harden.
Whereas, the factory finish underneath is a reactive finish which hardens by "cross linking of the polymer": it is a two component polyurethane, powder-coated epoxy, "UV cured" stuff or some such.
In this situation, a solvent (e.g. acetone + toluene/xylene lacquer thinner) should take off your paint, while not attacking the factory paint. Try it in an inconspicuous area of the frame like the bottom of the bottom bracket (if you painted there) or chainstays.
Do not use anything abrasive: soft cotton cloth only, soaked in solvent. Use rubber gloves and work outside. Situate the work piece downwind relative to yourself, or wear a respirator.
If you spray painted directly onto the original finish and that paint has stayed in place for 5 years, it's not coming off without removing at least most of the original paint. Even if the two paints used different bases (say one oil and the other latex) they are bonded together so well that they will not come apart.
Your best option is to strip all the paint, then repaint the entire frame nicely.
Chances are it's a paint with a layer of clear coat underneath the paint you applied.
I'd get some wet & dry sandpaper (black stuff) - about 80-120 grit to start with - and scuff up a portion of the frame. Clean it often with a rag and some soapy water to make sure as soon as you get to the clear coat you have stopped. If that works then do the rest, and finish off the job with some 400-800 grit sandpaper to take out the sanding marks and then hit it with some rubbing compound or polish (stuff designed for cars will be cheap and will work well)
You will be there all day with rubbing compound...
To my mind the one recommendation for using sand paper is ill-advised, even if it is a high grit wet/dry sandpaper. However, I haven't tried it so maybe it works like a charm.
What I have done for a bike that I bought used and someone "ruined" the gorgeous original paint job, was used acetone and it worked like a charm.
Keep in mind that the clear coat paint quality is a "buffer" zone to the coloured paint underneath the clear coat. Typically the higher priced bikes have better quality clear coats.
Anyway, another thing is that the longer acetone comes into contact, the deeper it seems to "melt" the paint away. I used a rag and did kind of a two step process of doing small sections and using a clean rag for the second pass to take away the residual offending spray paint. Worked for me!
I have removed vandal spray paint from a cars with rubbing compound. If you just misted it and bike had nice baked paint then there is a good chance. It might not work but it is sure worth a try.
Also search on overspray removal. I used to take my truck inside the gate at a refinery and it got over sprayed badly a couple time and they managed to remove it without repainting. Don't know how they did it but somehow they did. But I would start with rubbing compound.
I purchased a framed art piece & the frame was sticky . I started to clean it because I wanted it another color , I discovered the color I was going to paint it underneath .It was shiny , so I carefully used liquid detergent & water with a toothbrush & all the paint came off without damaging the paint underneath .Beautiful frame , I don't know why anyone painted would have painted it in the first place .
