On Wednesday, January 18, 2017 at 11:06:44 PM UTC-5, gray_wolf wrote:
On 1/18/2017 5:55 PM, Tim Wescott wrote:
On Wed, 18 Jan 2017 15:28:30 -0400, Leon Fisk wrote:

On Wed, 18 Jan 2017 13:02:13 -0600 Tim Wescott
wrote:

snip
Polystyrene putty with chopped fibers in it works quite well both as a
putty and as a glue for polystyrene parts. My dad's shop used to have
the local Glidden supplier custom-mix such putty. It was excellent
stuff. (May still be -- I don't know what the company uses now).

It won't necessarily stick well to metal, though. I'm not sure what
body fillers like Bondo use to increase the bond.

I found several youtube videos showing how to use acetone and
"styrofoam" packing material to make some:

https://www.youtube.com/watch?v=6E8bu2wLYGU

I'll have to remember that. Usually have some of both around. Looks like
it could be really useful stuff for making repairs...

Blech. I said polystyrene, meant polyester.

Bondo is usually polyester, which is a catalyzed material and far
superior to polystyrene. Bondo, for instance, should not melt if you dip
it in acetone.


Bondo is good stuff. I've used it to patch gas tank leaks.

FWIW, that's one application that 3M (owners of Bondo) specifically recommend that it *not* be used for.

I don't doubt that it usually works, but resistance to gasoline for polyester falls apart as temperatures rise above 120 deg. F or so, and the gasoline resistance of styrene (a component of almost all consumer-grade polyester resins) is poor.

--
Ed Huntress