I was researching MSDS sheets yesterday and found that the only difference listed in Class A and Class B sealants is that the Part A of the Class A has 10% Toluene by weight added. If that's the case, then what some have said of adding <15% Toluene by weight to thin Proseal should be perfectly acceptable, right (or at least <10% anyway)? Reason I ask is that I've contacted Flamemaster and PPG about doing this, and neither said thinning their sealant is acceptable, even though that is apparently what they do to make Class A sealant. I'm guessing that when they do it they are making a known quantity that they have tested, so they can validate the results through testing. When the homebuilder does it, the manufacturer has no control of what someone might do and how it might affect the sealant.
Am I correct? I want to make a final thinned batch of Proseal to paint over the seams and rivets so that I can look at it and say "it won't leak" before closing it up. Proseal is cheap!
Am I correct? I want to make a final thinned batch of Proseal to paint over the seams and rivets so that I can look at it and say "it won't leak" before closing it up. Proseal is cheap!