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 ?

What do the 'curing agents' actually do ? Catalyze the polymerization ?

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 ?

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 ?

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 ?

Any online references that address this ?

Appreciatively,

Courtney