Hi,

Recently I bought a used mtb with some obvious dents/cracks in it paint.
I have an idea of how I want to repair the dents, however what would be the best way to go about the cracks?

Cheers

Dennie

Is this a carbon fiber frame?

It is, however the sound seems fine, dull/muffled sounds when tapping it.

I'd do nothing about it. It the history of the bike. Character.

Perhaps I might put a little clear coat over it if I was worried about corrosion. Or just to help keep the paint from flaking off later. Or, if you feel the need to hide it more, then a match color of fingernail polish, touch up paint from an auto parts store or paint for model cars and airplanes from a hobby store.

If you do paint it, prep the spot with some very light sanding. Don't go overboard with the sanding in the search for perfection. You'll not get that since you had to ask. Bondo and other fillers can be used too if you want to smooth out the dent, but then you really will have to be perfect with the painting and everything else to hide that fix.

There is so much choice available to you. What do you want to do?

Yes was thinking of finding a matching nail polish and then just put on a bit of coating. Figured that just wouldn't work as well for the cracks as it would the dent.
Might leave it as is if I can't also hide the cracks properly but not sure yet.

Some poster on another thread described wheeling his bike into the bike cosmetics store to find the best color-matching nail polish for frame touch-up - ballsy and smart

That works.. smart as noted.
Another angle.. acrylic craft paints.. as is or mixed to match. Top coated w clear nail polish.. light sand if your fussy.. good car wax or similar to polish.

I'd take a preservative rather than restorative approach, and try wicking in some thinned clearcoat in the hope it would strengthen the cracked area of paint, reduce the appearance of the cracks and keep dirt out. But that looks to have been quite a heavy impact ...