Remove or Not Remove Partially Cured Epoxy? - Followup
Jay Chan wrote:
You are saying that a bit less hardener (3-to-1 instead of 2-to-1) will
result with the cured epoxy to be a bit more flexible, and this may not
be a bad thing depending on the intended use of the final product.
This is interesting and is good to know.
Well epoxy works by the two different types of molicules each having two
reactive sites, one on each end. Its a chain polymerisation reaction.
When it gets to run to completion, it form *LONG* chains and sets pretty
hard. If there is an excess of one component, you get un-paired
reactive sites left over. This limits the chances of a long chain
forming and so you get a lot of short chains and a jelly like result.
Its more damaging than just the dilution the same amount of an in-active
resin would cause. I suppose that for a non-critical glueing
application like sticking down non-skid, a certain rubberyness *may* be
desirable, but I've always found that bad mixes are unacceptably weak
*and* I wouldn't want to risk the long term health consequences of being
around inproperly cured epoxy.
Get out your scraper and a hot air gun and get it all cleaned off. If
its as badly off ratio and as poorly mixed as you say, 99% of it will
come off pretty easily. You wont be happy unless you've got rid of it
and fixed it right.
N.B. treat the stuff you scrape off as toxic and wear gloves &
appropriate protective clothing. You'll be much happier *without* an
epoxy allergy for the rest of your life (and you'll save a lot of money
as *IF* you get an epoxy allergy, you wont be able to work with the
stuff again so will be paying a yard through the nose to do repair work)
--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
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'Stingo' Albacore #1554 - 15' Early 60's, Uffa Fox designed,
All varnished hot moulded wooden racing dinghy.
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