I mistakenly mixed about 2 oz of pre-cat catalyst to a gallon of
lacquer, 1/2 oz more than what was called for. It never occurred to
me to simply add more lacquer. Anyway, my first coat of finish isn't
drying as fast as normal... more than 2 hours and it's still slightly
tacky. I sprayed late in the evening and the humidity has been at
least 80%, today, so I'm assuming these conditions play a small part.
Is too much catalyst the problem and will the finish dry over night.
I'll correct the mix tomorrow.
Strangely, it probably is. You would think that the catalyst would
the actual reaction and cause something like cracking or glazing.
Maybe it is
extreme conditions like doubling the catalyst. But the catalyst isn't
like one finds in epoxy, nor is it an activator to change the chemical
of the actual finish. According to the wonks at SW, when you mix the
the base, you are actually creating an entirely new product.
Being interested in so many things that are mundane and sometime quite
I actually went to a 4 hour class on using cat lacquers that was put
on by the Sherwin
Williams Industrial Coatings Division.
The only one I have used is SW. SW was completely specific about the
of their product, and advised using measuring cups for the catalyst,
and only mixing
in gallon batches as anything less than a gallon could produce an
strangely performing product. Since their product lasts well even
after mixing, it made
I would personally think that mixing in the exact percentages,
regardless of volume would
result in the same end product, but they say no.
The point is this; when you over catalyzed the product, you made you
own product, not one
that performs to the manufacturer's intention. For precats, adding
too much catalyst
will actually make the product dry slowly, and possibly corrupt your
understanding that the process that adding catalyst created a new
product (as opposed to
modifying an old one as one does when they add thinner to paint), I
thought adding more
catalyst would speed the process up like when you add too much
hardener to epoxy.
Not so, says the company rep. Since I like using really "hot"
finishes and spray
quickly, I am always open to speeding things up. I **specifically**
asked if more catalyst
would speed things up. The SW rep **specifically** told me that
fooling with the mix was
a recipe for disaster and also told me that adding too much catalyst
and under mixing
were the two most common culprits in precat problems.
I probably learned the most at the seminar/class in the trouble
shooting portion of using the
product. According to the SW guy, too much catalyst can actually get
your end product to
the point where it will not harden! It will dry to some extent, but
will have an oily feel to it,
and even then it might take a couple of days to get to that. This was
part of the "troubleshooting"
portion of the class. It will dry too soft, which defeats the reasons
(hardness and abrasion resistance) we use precats. It may also sag,
or even pool. Or is could go the other way and craze when drying.
Also, with too much catalyst it was pointed out that the final finish
may not be 100% stable
for a couple of weeks... maybe more. Remember, there is a big
difference in any finish between
"dry" and "stable".
Take that for what it is worth. This was one corporate man speaking
about the SW product
to a bunch of finishers that was wanting to make sure we followed ALL
so we wouldn't blame anything on his product if it wasn't
If I were you, I would call the technical help line usually found on
the can (or internet) and talk to
one of their industrial coating specialists. It won't be the same
guys that answer for consumer
goods, and some of those guys are really sharp and you have to know
you certainly won't
be the first one (or even 10,000 th) guy to do that. They will have
instructions specific to their
product on how to handle this. A quick call to one of my fellow
sprayers here was answered
with his opinion being that you will need to remove the existing
finish and start over again.
Do me a favor, Sonny. I don't use precats because I don't have anyone
calling for them, but I
am always interested in how things turn out in finishing. There is no
end to the learning
process in finishing..... none. We all get better, but no one knows
all of it.
If you call their tech line, please share with all of us exactly what
you find out, how they
tell you to correct the problem (in detail please) and who the
manufacturer of your product
is, and if they were helpful on the phone.
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