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I just roller primed a board then painted it a medium green with 5% hardener in it to keep it from chalking after a year or so. The problem is it got a little rain on it an blemished. So next day I lightly sanded, then another coat of paint with 5% hardener in it. Big mistake! I had chemical reaction all over. It seems to be worse where I sanded. Anyone else have any thoughts? John Arnott
-------------------- John Arnott El Cajon CA 619 596-9989 signgraphics1@aol.com http://www.signgraphics1.com Posts: 1443 | From: El Cajon CA usa | Registered: Dec 1998
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I would think that sanding the board then using Rapid-Prep again would solve your problem, but then again, I never leave projects in the rain to dry!
-------------------- HotLines Joey Madden - pinstriping since 1952 'Perfection, its what I look for and what I live for'
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I do double coats with catylized One shot on a fleet of trucks.I never had a problem. I do exactly the same as you did. I scuff with scotchbrite pads. I use 10% hardener. Did you use the One Shot brand name hardener? I wonder if the problem goes back to the primer? Please describe "chemical reaction"?
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John, Sanding opened up the surface, exposing a less cured layer. If you had let it dry again overnight after sanding, or put less hardener (or less thinner) in the second coat, you would have probably been ok.
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First of all, it never rains here in southern California. Opps. . .oh yeh. . .the roof leaks right there. Second it only wreankled where it was "cut" by sand paper. Third, it seems to me that when I use 10% "chromatic" hardener it seems to flatten the gloss! I normaly don't thin the paint if its fresh.
-------------------- John Arnott El Cajon CA 619 596-9989 signgraphics1@aol.com http://www.signgraphics1.com Posts: 1443 | From: El Cajon CA usa | Registered: Dec 1998
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John I just don't get what you say since catalyst is also a gloss enhancer as well as a hardener. I have been using catalysts in my paints for many years. Even though you may think that 1-Shots hardener is a new thing for sign enamels, Chromatic came out with it in the early 90's. At 5% you are not really adding to faster dry time. I believe the starting point is 10% and can honestly say that I use quite abit more during my usage. I however let it sit for at least ten minutes after mixing it in the paint to let the bubbles disappear. Haven't had a problem with gloss or drying time for that matter.
I always prep my surfaces with Rapid-Prep even after sanding as using automotive type stuff usually leaves an oily surface, or at least thats what my hands told me in the past.
-------------------- HotLines Joey Madden - pinstriping since 1952 'Perfection, its what I look for and what I live for'
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