======== Original Message ========
        Hi Techneters.

        I am looking for a fast curing epoxy, that will wet holes 11.0
mils or smaller. At present time we are using BUEHLER Sample Quick that
sets in 5 minutes and is cured in ~ 10 minutes. The only problem we are
having with this epoxy is that it has a very poor wettability of small
holes. So when you go to polish these samples the holewalls have a
tendency to collapse due to the lack of support in the hole.
        We used to use BUEHLER Epoxide with a cure time of about 2 to 3
hours. This agent had fairly good wetting properties but unfortunately a
little slow if you want to return results in a timely manner to the
shop.
        Does anyone know of a compound out there that cures quickly and
has a good wettability in 11.0 mils or smaller holes.

                        Thank you


Lance Rogers
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======== Fwd by: Richard MacCu ========
I too have been looking for this type of compound.  Here is what I've found
so far.

Acrylics, like Sampl-Kwick, for the most part are rapid cure and do not lend
themselves to Vacuum degassing for void filling.  Sample-Kwick specifically
can be mixed with a 1.25:1.00 Powder:Hardender ratio for better fill of
voids.

Epoxies are the better choice for this purpose since they have longer work
lives and many have low viscosity.  I'm still in evaluation, but 3M
Scotchweld DP270 works relatively well.

Hints for using epoxies.  Warmed mixed resins have lower viscosity and if
you plan to use a vacuum degassing do it on a warmed, 120F, compound.
Make sure to degas before pouring molds since the bubbling will be messy.
Degass again after pouring to fill all voids.  Many of the epoxies that suit
themselves to this process are best cured in an hour at 175F.  Once cooled
they will reach their max hardness.

If you use a Nelson-Zimmer style microsectioning setup, be prepared for long
cooldowns.  Try preheating the molding jig at 175F and then pour the
compound.  Half the bake time and this may improve cycle time.

Also, epoxies have far greater bond strength than acrylics and molds must
have plenty of release agent.

Hope this helps and Good Luck

Richard MacCutcheon
BFGoodrich Data Systems Div.

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