Foam + Bondo Question.

[JokerOfArkham]

I'm currently working on a foam Starlord helmet and was planning on using bondo to smooth out some of the edges where the foam meets. I know that bondo isn't recommended for foam as it's not exactly flexible. I figure though that for a helmet, it doesn't need to be overly flexible. My main question is this: Should I use plastidip before applying bondo or should I apply the bondo to the foam then plastidip the whole thing?

 

[Fireman Dan]

Hey Joker
Try this product called Epsilon from Smooth-on products. It's perfect for foam. It will harden your pieces and can be sanded and filled with spot putty. The product is self leveling, but I recommend using a good paint brush when applying

 

[JokerOfArkham]

Hey Joker
Try this product called Epsilon from Smooth-on products. It's perfect for foam. It will harden your pieces and can be sanded and filled with spot putty. The product is self leveling, but I recommend using a good paint brush when applying

Thanks for the suggestion!! I'd be totally game to try it out, but I'm trying to get this done before May 2nd, so I don't really have the time to order the Epsilon. I'm just wondering if the Bondo will adhere properly to the foam or if I would need to plastidip it first.

 

[PolyversalAri]

As someone who has personally experimented with Foam / Bondo it is not an ideal combination, but it will adhere if you rough up the foam edges a bit first.

If you are going to try this method, definitely Plasti-Dip last. I think that Bondo over Plasti-Dip would make it more likely to fall apart since Plasti-Dip is meant to peel.

 

[Fireman Dan]

Another solution is to make Rondo. A mix of 50% Resin and 50% Bondo. I know for a fact it will stick to foam treated with plastidip I recommend you work in small batches and wear a respirator.

 

[Mikki Haight]

Rondo for working on a budget. Smooth-On's XTC-3D also works on foam but it won't build up like Epsilon does, just gives a fairly hard (albeit thin), glossy surface. I tried straight Bondo on resin-coated foam and the bondo all curled up at the edges. Always test on a scrap piece when in doubt. Good luck!