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All M. L. Campbell post catalyzed coatings: (except
catalyzed vinyl sealer) require a 10% (13 oz.) by volume ratio of M.L.
Campbell CareCatalyst C149 1 per gallon. Catalyst should always be added
to the coating before any reduction of the coating takes place. No
sweating in (reduction period) is necessary before the use of catalyzed
M.L. Campbell products.
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Proper catalyzation amounts: All catalyzed products are formulated
with the proper amount of resin to lock up with the recommended amount of
catalyst. Adding more than the recommended amount of catalyst allows for
free catalyst in the coating that can not lock up with the resin. This can
lead to color changes, hazing in the finish and/or possible acid damage
(burning) to the wood surface.
Undercatalyzation
can effect the catalyst cross linking reaction (cure) and dramatically
effect the hardness and durability of the finish.
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Finish curing: To insure the proper catalyst reaction, after
application, these sprayed materials should be cured in a drying room
where the temperature is 68" F-70" F. If the drying area is
lower than this temperature, it is possible to have a cold cure take place
and the finish will not exhibit the durability and chemical resistance of
a properly cured finish. The drying room area should be kept at the
recommended temperature for 6 hours to allow for proper cure.
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Sanding: M.L. Campbell Post Catalyzed products are extremely
solvent resistant and hard. Because of this, the surface must be sanded in
between coats to assure proper intercoat adhesion. We recommend sanding
between coats within two hours of the product being recoated. The reason
we recommend sanding within two hours of recoating is that there is an
ongoing acid cure reaction that continues to harden the film and if too
much time passes between sanding and recoating, it is possible the surface
will reharden and improper intercoat adhesion may result. A 320 grit
no-fill type sand paper is recommended and will provide a good intercoat
bond. Remove sanding dust before recoating.
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Recoating: M. L. Campbell
products with the exception of Clearlite Plus do not have recoat windows.
Clearlite Plus should be recoated within 1 hour after it is dry to the
touch, or after 8 hours. Care should be taken with all post catalyzed
finishes when sanding, not to sand through the previous coat as this can
lead to lifting of the coating in the sanded through areas when the next
coat is applied.
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Pot Life: The pot life on all M.L. Campbell post catalyzed finishes
is 24 hours. Materials used within this time period will exhibit the best
chemical resistance and hardness. To use coating after the recommended 24
hour period up to 72 hours, store the coating in a cool area. Catalyze an
equal amount of fresh coating and mix with the old coating. Use the mixed
material as a first coat. As a general rule, for best chemical resistance
and hardness, always try to use catalyzed material within an 8 hour
working shift.
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Film Build: Catalyzed coatings obtain their excellent
chemical and wear resistance by the hardness of the film. If too much
coating weight is applied, the thickness of the coating weight combined
with the film hardness will not allow the finish to expand and contract
with the natural wood substance it is applied to. This will lead to film
wrinkling/cracking. Recommended dry film build on all post catalyzed
product after sanding should be 4-5 dry mils. Heavier applications of
finishes are not necessary to obtain either chemical resistance, long term
durability or hardness.
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Viscosity: High solids post catalyzed coatings are very
susceptible to viscosity changes due to temperature, product aging, or
catalyzation. After establishing satisfactory application results with
these types of products, always know the viscosity of the product that had
produced the best application characteristics for you. In the case of any
future application problems, always check viscosity to make sure it is the
same as when the product's application was proper.
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