picked
up at a recent presentation given by PRC-DeSoto.
Wish I knew this stuff a year ago.....
First they consider this stuff fairly safe to work with although some
versions do have chromate in it which has more health concerns involved.
Good
ventilation was recommended, and eye glasses if using the semkit
cartridges.
Grade B is extrudable, grade A is brushable. There is also a C grade
rollable
version for faying surfaces with a C-20 to C-96 hour working life. Might
be
useful for building floats. It is much thinner than B but thicker than
A.
They seemed to prefer the PRC-1422 for gasoline and the PRC 1440 for
kerosene. But they stated that either product was fine for gasoline and
gasoline with up to 20 to 40% alcohol in it.
There is a minor compatability issue when using the dichromate cured
PRC-1422 in contact with the Manganese dioxide cured PRC-1440 or
PRC-890 type of product that Murphy supplies. They recommended thorough
cleaning before applying the 1422 and the use of their adhesion
promoter.
They also highly recommended brushing some adhesion promoter on when
repairing tanks, since the surfaces will not be as clean as when new.
They recommended that the buna rubber 1005 sloshing compound be
considered as
a temporary fix only, not a permanent repair.
They have no preference for what solvent is used for cleaning. Acetone
was
recommended as safer than MEK, and a slower evaporating solvent blend
such as
Dessoclean 110 was also recommended. Wipe with a wet rag and then in the
same
direction with a dry rag.
Apparently the hardener should be well mixed before use unless the
entire can is being used. Apparently the lighter carrier in the hardener
tends to separate which causes the exact type of inconsistant curing
problems
that I have experienced with old proseal. It also explains why even with
accurate weighing, you may run out of one component before the other if
the
hardener is not mixed before weighing.
Apparently it is also not sufficient to mix proseal until the colour is
uniform. It requires somewhat more mixing as the product requires a
certain
minimum amount of shearing action to properly cure. Keep mixing for a
bit
after the colour appears to be uniform.
Part of the written spec is the requirement for a tooled filet 1/2 inch
wide
on each side of the joint.
If not available locally, the product is supposed to be available for
ordering with a credit card from 1-800-AEROMIX.
disposable syringe is useful for applying proseal to hard to get places.From the audience, apparently some people find that a 60cc plastic
Also
apparently most any paint stripper will remove proseal. THe stripper
will
leave behind a wax residue that must be cleaned off though.
There is a 2000 degree version available for firewalls and an
electrically
conductive version for under antenna bases.
If you ever want to remove an access panel (fuel tank or not) without
destroying it, there is a lower adhesion prc-1428 specifically for that
purpose.
If you are installing a plastic windshield use the 1425 (or 1829 rapid
cure)
product which has no solvents to eventually cause crazing.
website at www.prc-desoto.com
Ken
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