Go to http://www.systemthree.com/index_2.asp -- register -- download "The
Epoxy Book" in pdf -- read the introduction and Basic Chemistry. Unless
you're an organic chemist, this is all you'll be able to digest. (I can
almost understand it while I'm reading it, but it's been fifty years since I
took P-Chem.)

Note that only a very foolish company would give you the exact details of
their formulations. They've spent many year$$$ coming up with these. I
believe they all start with the same basic resins from DuPont or whoever.
The magic is in the additives and there are huge differences between brands.
Contrast the glasslike stuff from the hardware store for mending china with
the resilient bond formed for building boats.

As far as ratios go, the 5:1 used by the Gougeon brothers is harder for the
user to measure accurately than the 2:1 used by System Three, but it
apparently is closer to the basic resin as brought in by tank car.

The appendices of "The Epoxy Book" give mechanical properties and usage;
e.g. coverage, curing times, etc.

Roger

http://home.earthlink.net/~derbyrm

"Courtney Thomas" wrote in message
nk.net...
Dave W wrote:
They are different formulations. Follow mfgr. ratio data exactly. This
is not a place for experiments!
Dave
Thank you.

I can see I failed to adequately state my concern :-)

Chemically, what is the difference in the resins when using the different
formulations that require different amounts of hardener ?

If only the viscosities are different, how are these different
formulations attained ?

Also, what is the difference in the hardeners, if any ?

Is there a known website that fully delves into this without bias ?

Thank you,
Courtney