Talk Composites - The Forum for Advanced Composites

Issues with CF Skinning.

http://www.talkcomposites.com/Topic33248.aspx

By LukeSGee - 7/5/2019 6:38:38 PM

Hi all,

I am new to composites and I am currently trying to skin some parts for my car.

To begin, I had issues with bonding the fabric to the parts but I have seemed to solved my issue by not folding the excess behind the part for a clean edge. My main issue at the moment is sanding. I am struggling to get a nice flat surface and I am reluctant to use 120 to begin flatting as I always end up with scratches I struggle to sand out. What is the most efficient way to get a smooth finish without sanding forever. Also, what is the best way to remove drips that have cured and also a bulging edge where the resin has collected on a vertical edge on a part? I worry when I’m sanding I will hit the fabric.

My last issue seemed to be on the weave when I finished sanding, it looks like a void between the resin and the weave as well as moisture under the resin when damp outside.

I am using XCR resin and have been told it is self levelling and does not have air bubbles but I keep getting bubbles!

Thank you

By MarkMK - 7/31/2019 7:41:36 AM

If a better gloss finish is desired also, it's worth going up to 1500 grit, at least, as 1200 grit can take quite a bit of machine polish work to get to a good shine, especially with a relatively hard epoxy. 

If I'm doing any repair jobs using epoxy, I usually go up to 2000 grit, which usually results in only needing a couple of passes with the polisher to get a good gloss. If you're parts are large, though, this might feel a bit too laborious, but going to 1500 will likely make getting a good shine a lot easier