Courtney Thomas wrote:
Paul Oman wrote:
Courtney Thomas wrote:
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
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Hi Courtney
There are about three different epoxy resins (bis A, F, and novolac).
Just about everyone uses Bis A....
There are about 60 different curing agents that can be used.
So.... most epoxies are, or can be, a blend of different curing
agents. On top of that there are thinks like nonyl ... that can be
added to part A or B to even out the mix ratios, lower the price,
change visc. etc.
The curing agents are a lot more expensive than the resins so
forumulating an epoxy with with a 4 to 1 or so mix ratio (instead of
a 1 to 1 or 2 to 1 ratio) saves the formulator $$ (or increases their
profits)
paul oman - progressive epoxy polymers, Inc.
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Thank you Paul.
What's the difference between bis, A, F and novolac ?
********* Bis A resins are the most common. Bis F and
especially
novolac provide much better chemical (an a bit more
chemical resistance.
What do the 'curing agents' actually do ? Catalyze the polymerization ?
******** they are the other half the the equation needed
for the
reaction to happen the forms the complete epoxy
Is the reason that everyone doesn't use the same 'hardener', because
different ones lend a different character to the curing process,
otherwise, the same end product... results ?
******* yes pretty much the same end result, but yes
different ones do
have dif properties (cure rates, times, blushing
properties, etc.
Suspect $$$ is the controlling factor for some epoxy
manufacturers.
So, is the bottom line that....if you can find a 1:1 or 2:1 mix that
will satisfy your needs, that's the best way to go and the more exotic
formulations are also more circumscribed in terms of usage hence more
likely to be inappropriately applied, such as low temp applications,
etc., that ultimately don't properly cure due to a flawed application
process, hence fail ?
******* in a marine setting they pretty much all will work.
Boatbuilding, marine applications, etc. are not very
demanding for
epoxies, hence there are lots of them out their (we think
ours in one of
the best!)
Would this be just one more example of vendors bamboozling customers
with attempts at masking a generic product with proprietary
'technology', witness the auto manufacturers and their glomming onto
electronics, or do some actually have worthwhile differences and
related costs and PERFORMANCE, that justify their claims and charges ?
****** lots of ways to make an apple pie. It's all apple
pie but we
all have favorites (and some like it with raisins). Yes,
most if it is
very overpriced.
Any online references that address this ?
****** yes, but afraid they are all written and posted by
me! paul
oman - progressive epoxy polymers
Appreciatively,
Courtney
--
"Living on Earth is expensive, but it does include
a free trip around the Sun every year."
============================================
PAUL OMAN Progressive Epoxy Polymers, Inc.
Frog Pond Hollow - 48 Wildwood Drive
Pittsfield NH 03263
10:30-3:30 Monday-Thur EST 603-435-7199
VISA/MC/Discover/Paypal
http://www.epoxyproducts.com
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