Questions on Epoxy....

Re: Questions on Epoxy....

Keith Newton

You ought to ask System 3 that. So brands may not set up and just stay gummy forever.

That’s one thing I like about FGCI is that it’s very forgiving, cost about half as much and also a 1-1 ratio. I just set two small solo cups side by side then pour in equal amounts so they come out at the same level, then mix them together. Mixing smaller batches, and or not leaving it in a container with any depth will help it from kicking too fast.

Re: Questions on Epoxy....

Brian gunsmith From colorado

When I was a practicing gunsmith, I used two different kinds of Epoxy. One I called "runny epoxy" tradenamed Acraglas with a consistency of maple syrup mixed 1 part hardner to 4 (or was it 5) parts resin. No real accuracy was necessary. Did it by volume. Small plastic cups. Units of measure on container. whatever was useful.

Worked well. Exothermic (think the term is, it gave off heat). The other epoxy, acraglas gel was mixed 50-50 hardner to resin. consistency of peanut butter. Not for use in sandwiches. Never had a failure of any kind. Except for release agent. Sometimes epoxy would adhere to the barrel. Source of both epoxies was Brownells, trade name Acra-glas. They also had 5 minute and other timed epoxies. We used the 50-50 mix for bedding. The runny Acraglas was used for stock repairs. Both could be colored. As many stocks were of claro walnut, black worked well.

Re: Questions on Epoxy....

John in NM

In general, too much hardener will cause too fast a cure. The epoxy will get too hot and you'll get bubbles and later cracking as the epoxy cools (my experience is with West System). The other thing I found was that the mix ratio had to vary depending on the size and shape of what your pour looked like. If you were filling a large, chunky void, you needed to mix lean with the hardener - it doesn't sound like you do anything like that with it though (we were filling cracks and voids in mesquite wood).

With 5 minute epoxies, it seems like too much of one component or the other causes gumminess or a rubbery cure. Presumably that is because there is no where for the thick excess goop to run out like the water does in concrete.

Re: Plato has your answer...

TomD

WEST, which is in the case I am referring to a 5-1 mix, needs to be mixed to within 3% to get the promised structural qualities. It is a bit like Platonic love:

“Love is born into every epoxy being; it calls back the halves of their original nature together; it tries to make one out of two and heal the wound of epoxy nature. Each of them, then, is a 'matching half' of a epoxy whole…and each of them is always seeking the half that matches him.”

What it is not like is a catalyzed product like polyester resin, where a minute amount of catalyst will eventually win over the whole mix. However, the catalyst is also pollution in the end mix, and over time levered apart a huge proportion of the fleet of boats that were made with it.

So what happens if you miss-mix, or do not properly measure, is that some molecule of epoxy will never find it's matching whole. You will not reach structural ideals, and you will have inclusions in your mix, potentially toxic, that are degrading your mix.

If you buy 1-1 mixes, they are mathematically, and by design made to be, less affected by poor handling. In general, one should assume they will tolerate bad handling better, as that is the intention usually built into their design. That said, they do not normally have the properties of the more finicky products, so you are not stepping up to the higher performance in the first place. Of course, many of these products have features that make them more desirable, or the higher performance is not required in the first place.

Re: Plato has your answer...Got Some answers

Barry Irby

Texted my questions to System Three about T-88.

Basically they said if I got within 10% of the correct ration I was good to go.

I also asked about thinning it drastically with acetone to use it as a wood hardener (saw it on YouTube, must be OK). They said to thin it with DNA or Lacquer thinner but only 10%. and it would be better to use some of there wood hardener stuff.

And a question for you Tom, you seem to have lots of experience with resins and epoxy. River tables, are they going to hold up in the long run? Isn't the wood going to squirm along those long joints and turn loose? And will the resin remain polished and bright?