A bit of dodgy fibreglass work this evening as I attempted to make a small air duct plenum to go over my oil cooler housing. I started by shaping some foam, and then covered it in masking tape and attached a 3" gutter fitting. I then covered this in a few layers of fibreglass. Once it had gone off (with a little help from my hot air gun), I then cut out the foam, stripped away the tape, and sanded back the sharp and rough edges.
See pictures below. It's very apparent that I missed a few spots as there's some significant holes. I'll fiz all these with some more fibreglass.
Foam block shaped and ready for fibreglass
I ended up with some big holes
I'll add more fibreglass and resin/flox to complete to a standard that will work
