[alex.s]

Originally Posted by adouglas

No, but I used to be a whitewater kayaker so I had learn a bit about that kind of plastic. Boats are made of it. With a whitewater boat, the seat should fit like a pair of nice, snug jeans.... no slop. So you glue in closed-cell foam and carve it to fit you.

The problem is that like paint, glue doesn't stick well to this type of plastic.

The issue is that it's made of long-chain polymers, which look like piles of spaghetti under an electron microscope. There's nothing to grab onto.

You have to do some voodoo to break the polymer chains and create a surface with some "bite."

The trick is to very lightly pass a flame over the surface. Not enough to deform the plastic, but it does alter the molecules.

I wouldn't try that with this project. I don't know if it'd work to improve paint adhesion, and you can easily screw up and melt the part. I'm also not entirely sure that those pieces are in fact LDPE... they just look and feel like it.

voodoo? i call it acetone slurry.