covering plastic cowl
 

been trying to cover a plastic cowl with Ultracote

how do you keep from getting all those little air bubbles?

You are better off glassing the cowl after roughening it up a bit, then sanding and painting.

Plastic and heat don't mix.... Paint the cowl

+3 ;) paint.

Hi!
Plastic cowls are supposed to painted, not covered with plastic film!

If you must use Ultracote, making a tiny hole with your hobby knife will let you get the air out. Don't expect it to look good for long though as the thermal cycling and fuel residue take their toll.

I had a 26cc Yak that I converted from glow to electric. I covered the huge muffler hole with ultracoat and it worked great. I only had about 1" or less of covering around the edges though; whenever you cover a solid surface you run the risk of bubbles. You can try popping them with a pin and shrinking the covering. There is a chance the covering was not stretched enough when applying though, in which case the bubbles may not come out.