Hypothetical - repainting a frame
The paint jobs on modern frames seem to be more scratch resistant that a decade ago, or perhaps it's my imagination. If I wanted to change the colour of an aluminium frame that already had a high-gloss layer of paint, such as this: http://dahon.com/intl/vitessed7.htm , what would be the best way to go about it? Would it be necessary to strip the current paint off or would a new layer of paint adhere to that high-gloss surface? What would be the right sort of paint to use?
In fact, how easy is it to strip the paint from a frame? I tried that on some chromoly forks about 10 years ago and remember it being very awkward: whatever chemical I was using either wasn't strong enough or wasn't appropriate for the paint and it took a very long time.
I wouldn't do such a thing at home!
Originally Posted by chagzuki
Normally its done with strong chemicals or with plastic ball blasting or both. Afterwards powdercoatet, also not possible at home. It should not be very expensive though.
The more durable "paint" found on most folding bicycles today is actually powder coat. This is a plastic which is bonded to the frame with heat. It won't bond to paint, it needs to be applied to a bare frame. Most powder coaters can also strip your existing frame for you.
Around here (Seattle, WA) a basic one color powder coat job on a normal bike runs about $100.
No spray paint or anything home applied is as durable. I use spray paint when I'm touching up repaired areas on frames, but send them out for powder coat if the whole frame needs paint. Powder coat is also much more environmentally friendly than paint, there are no volitile organic compounds used to apply it. The powdercoat is applied with an electrostatic charge which holds the plastic beads to the frame until it is melted in an oven.
Sandpaper or a wire wheel on a drill will do the job quicker. Remember that you don't need to strip off all the paint. If there's no rust, you can simply rough it up and paint over.
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