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Old 08-02-2012, 12:27 PM
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Brian Martin,Freelance adviser
 
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Quote:
Originally Posted by skip99 View Post
I must be having a slow day....how does using a fast reducer retain solvents? wont the 870 evap. out quicker at 85 than at 70? or does the say,,,885 keep the base wetter longer to not skin over and let solvents out?

I've just never had a problem,,,spray 870 up to about 85 degrees and use 885 if it was real hot..

get technical,,does it have to do with tail thinners and such?

you think i would have been better off using 885, ?
I can't get "technical" I can only say that when you pile on a number of coats without proper flash time, solvents can get trapped. And in fact when it's too fast it can do it worse than if it's too slow! Let's say you using the fastest reducer designed for 50 degrees. You are spraying this paint in 100 degree weather. You fill up your gun and you bomb on three coats one after another very heavy trying to keep it wet because it's flashing so fast. The top layer of the film CAN flash off and does, creating a surface that is now closed up so the solvents under it can't get out. You feel it, it feels "dry" and you put clear over it. Now the clear seals that all off. You have solvent trapped in the base, that solvent is keeping isos from linking up, it isn't "cured" and is soft. It begins to move around, sink, etc.

That is why there are many ways it can happen. Simply applying it "correctly" with the wrong reducer or using the right reducer and applying it wrong can produce the same trapped solvents. Just as Tech said, then you have the color issue as Barry said, there are many other factors. I call it when the planets are aligned, it's a perfect storm. Sorry about the double analogy.

Brian
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