On 9/27/2014 6:08 PM, dpb wrote:
On 09/27/2014 4:39 PM, Bob wrote:
Hello,

I may be wrong, but I think that Gorilla Glue product is a Polyurthane
glue.
Correct ?

In any event, when would one use this Gorilla glue rather than, e.g.,
the typical 2 part epoxy ?

Would be for a wood project.
...

The original is polyurethane, yes. There is now a wood glue that is PVA.

The only reason to ever use the original for a wood glue is if must have
fully waterproof glue, not just the ANSI tests. It isn't as strong as a
PVA and has the other disadvantage that it foams on curing as well as
does not clean up w/ water.

It has the advantage over PVA glues for bonding other materials where
the PVA glues don't work but it's simply not of much real use for normal
woodworking. It is somewhat cheaper and is of a little less bother than
the two-part resorcinols, but I'll take one of them over it despite that
because of the foaming nature that is such a pita.

--


Correct and I don't think the polyurethanes have the stability of the
other glues.

Gorilla glue sometimes comes in handy but my biggest complaint is that
moisture absorption hardens it and makes it useless in the package.
I think the bottle is polyethylene which is one of the worst barrier
polymers for moisture, oxygen and CO2.