what paint on aluminium frame?

Unknown

I have quite a few fairly large shiny paint-free patches on my MTB frame as a result of crashes/wear and tear/bike racks etc. cant afford a full respray job, but dont want to leave them totally bare either.

is there a paint I can put straignt on? or will I need a primer? is it OK to use those car touch up paint thingies from halfrauds on an alu bike?[:I]

oh, oh, oh, oh!!!! the baby elephant please!!
www.ekroadclub.co.uk
www.motherwellac.com

llllllll

Touch up paints will do be fine, but it's best to use a primer as well. I painted a whole frame without primer (Halfords spray paints) and the quality of the finish was fine but it was very weak and chipped in no time. They used to sell the touch up paints in packs with a small tube of primer as well as the top coat, don't know if they're still avalible.

carlstone

For aluminium I think you need an etch primer which eats into the metal to provide a good key and before applying rub it down with some fine grit wet dry sandpaper, again to provide a good key. However for small patches a touch up stick may be sufficient on its own. I'd give this a try first and if comes off quickly go down the other route.

My bikes:
http://www.filehigh.com/viewimg.php?f=29099&i=291574
http://www.filehigh.com/viewimg.php?f=29099&i=317809

peterbr

Aluminum usually has a zinc chromate primer or epoxy primer, so not the same as a normal auto primer for a steel surface. Lightly clean with a scotbrite pad first (not wire wool) and degrease with solvent. The "toughness" of paint depends on how "plastic" it is. This is difficult to achieve without two-pack formulations which are too toxic for home use. You can achieve something like this using an air-dry plastic coating as a lacquer - this can look very good when you cover decals too. However you then make it much more difficult to repair convincingly next time.

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