Talk Composites - The Forum for Advanced Composites

wet-sanding creates dull surface

http://www.talkcomposites.com/Topic1228.aspx

By brummelisa - 4/9/2012 9:42:48 AM

Hi,

I'm almost done with my bike-frame and I have painted the whole frame with 5 layers of resin.
It has dried in 48 hours and when I started to wet-sand it (using 400,600,800 and 1200) the surface is really dull.
Do you know why this is:
Is it poor sanding (I actually tested with only 1200 and it is still dull)? or has the resin not hardened yet?

As soon as I put water on the surface it is nice and shiny again, but when the water has dried, the dullness comes back.
By Dave - 4/10/2012 12:40:58 AM

If your planning to spray the clear coat then as long as there aren't any big scratches you wont notice it. If your not spraying the clear coat then you'll need to do this to the clear coat: Even wet sanding with 1200 -2000 grit will look "dull" but if you have worked your way through the grits then you should have a nice flat and smooth surface with no scratches. To get a glossy, shiny finish use a polishing compound like "Mirka T10" or "3M Finesse-it". It will take some time but grab a lint free cloth, a nice blob of polishing compound and rub it in quite firmly, in a circular motion then once the compound has mostly faded get a clean lint free cloth and buff it up. You may have to do this several times depending on what polishing compound you use / grit you use. I don't think using an electric polisher would help you much as im guess the frame is tubular.

Just some help as no one else has commented. However other people may have better advice?


Dave.