Harbor Freight bondo & XPS foam ASAP ?
Posted:
Tue Jun 26, 2018 11:19 amby rustytoolss
Will Harbor Freight bondo melt XPS pink foam went direct contact is made ? Better to ask now...than to find out latter.
Re: Harbor Freight bondo & XPS foam ASAP ?
Posted:
Tue Jun 26, 2018 11:49 amby tony.latham
rustytoolss wrote:Will Harbor Freight bondo melt XPS pink foam went direct contact is made ? Better to ask now...than to find out latter.
Every Bondo product I have used is based on polyester resin. And yes, that resin will melt pink foam.
T
Re: Harbor Freight bondo & XPS foam ASAP ?
Posted:
Tue Jun 26, 2018 2:08 pmby rustytoolss
tony.latham wrote:rustytoolss wrote:Will Harbor Freight bondo melt XPS pink foam went direct contact is made ? Better to ask now...than to find out latter.
Every Bondo product I have used is based on polyester resin. And yes, that resin will melt pink foam.
T
OK...I need to fill a gap about 3/4" wide around an XPS foam fake fender. What can I use. I really don't want to "great stuff" so darn messy. I hate that stuff
Re: Harbor Freight bondo & XPS foam ASAP ?
Posted:
Tue Jun 26, 2018 2:36 pmby KennethW
I have used gorilla glue mixed with a little water. It will foam up. But will be harder then the XPS foam.
Re: Harbor Freight bondo & XPS foam ASAP ?
Posted:
Wed Jun 27, 2018 11:01 amby KCStudly
GG will make relatively large bubbles when watered and not constrained. It will expand and the surface will skin over, but once you cut into it it will have big voids; at least that is my experience in humid New England. Same goes for GS.
You can mix saw dust into TB2 and use that.
If you are topping with other vinyl paint products, PVA glue (TB2 or 3) and are not planning to use epoxy/fiberglass, you can use "light weight ceiling spackle" (vinyl based). In the hardware store it will be in a plastic tub that feels empty (right next to the gypsum based spackle that feels heavy... don't use the heavy stuff, it will harden and crack). The light weight stuff can be used right out of the tub. It is indoor/outdoor, and is water based so cleanup is easy. It can also be mixed with foam dust, saw dust, and/or TB2 to act as extra filler/binder/extenders (the dusts suck some of the moisture/pliability out of the spackle, while the glue puts it back... the glue is much cheaper than the spackle, so I experimented some trying to extend the spackle and make it sand more like the base foam). Just be careful sanding around the edges as the mixture will tend to roll up at an edge if sanded too aggressively; just block it down close, working from the center toward the edge of the work area, then feather back over it using straight spackle.
I used the vinyl spackle and then decided to switch from PMF to epoxy/fiberglass. I did a lot of guide coats of spray bomb paint while body working larger areas (just dry mist coats that did not eat into the foam), and that seems to have sealed the faired areas well enough for the epoxy, but if I had known I was going for epoxy/FG I would not have used the spackle to start with. PVA glue (TB2) over vinyl is fine, they are essentially the same.