From: RWolf99@aol.com
Message-ID: <1af22c7.36b1e116@aol.com>
Date: Fri, 29 Jan 1999 11:25:58 EST
To: lancair.list@olsusa.com
Subject: Epoxy by weight
Mime-Version: 1.0

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In a message dated 1/28/99 9:06:07 PM, you wrote:

<<By the way, the published ratio is 100:44.5 by weight.  I don't think anyone
could possibly be effective at controlling that .5 amount and in fact guess
that just about everyone fudges on the light side of 100:50 or 2:1>>

I use a digital scale from Edmund Scientific, although they are available
elsewhere.  For about $100 this little unit measures to 1 gram resolution.  I
had an epoxy pump but I gave it away.  (Note:  I we had to do large layups,
like on a Long-EZ, the pump would be better)  Faster than a balance scale,
it's worth every penny.  This works fine for all my purposes, but then I've
not yet had to mix more than a 16 oz mixing cup's worth yet.  

For large jobs, like filling up the gap between the stub wing skin and the
spar, one would premeasure several cupsful, hardener into one cup and resin
into the other.  One would than pour the hardener into the resin cup when
needed.  You can even measure the residual in a hardener cup and add a skosh
extra to compensate if you're worried about measuring hardener into one cup
and pouring it into a separate resin cup -- haven't done anything this large
yet.

Usually I measure out an amount of resin into a cup on the scale.  I then use
my calculator to determine the amount of hardener needed, hit the "tare"
button and pour that amount of hardener into the cup on the scale.  It works
well with Hysol, too, but the stuff is so viscous it takes a little more
effort.

I also discard my epoxy when the one year life is up, so you might consider me
a little anal on this subject.  But I don't use hardware store bolts in non-
structural applications -- why should I use expired epoxy there?

- Rob Wolf
rwolf99@aol.com