Ever get 'craters' in your paint ?

H

hans4811

Hi all,
Let me begin by saying that I live in Florida and its been very hot, very high humidity. Have been laying down some SPI epoxy on my '55 for the past few weeks. And everytime I'm getting little pin-head sized craters in the paint...all over. I've done everything I thought possible for moisture control...30+' of copper piping, water traps, filters, paper filters, desiccant snakes, deisiccant gun filters...u name it...100's of dollars on all this crap! I've got a 60gal, 5hp Quincy compressor thats inside the garage, behind a sheet of plastic I'm using for my 'paint booth'.
Granted, this is only epoxy and i'll be sanding most of it off, but worried that the 2k might not cover it or worse, I'll get the same result in my base/clear !

Anybody else having this problem? Not sure if its moisture or a gun setting or what....using an Iwata LPH400 at about 25-28psi at the gun, at the wall wide open...appx 115 psi.

Frustrated beyond belief...help !

Ken
 
Looks like its one of two issues with the epoxy and my best guess at this point is the scfm being air at wall is 115, need 125 min for a 25ft hose, so you might try raising air at gun about 5lbs to compensate, like 33-35lbs. Sometimes that will work and sometimes it won't.
With the snake water is not the issue here.

Primer will be fine and base will be fine, scfm only screws with epoxy, SS and Clear.

Also try inducing overnight, may help some.
 
Really...interesting....I could go higher at the wall Barry, like you suggest to 125psi, just never thought of doing that. I've got at least a 25' hose, maybe longer, not 100% sure and not at home atm to check. The desiccant snake I've got is right before the hose, big ol' red thing, like 3-finger thickness....

You said one of two issues...what was the other, were you thinking moisture or something else ?

- - - Updated - - -

...plus I'd really like to get this fixed before I get to clear if its an issue there as you say...don't wanna be sanding for the next 3 months...lol.

Thanks,
Ken
 
Crank the wall pressure up as high as it will go, it costs you nothing, mine at home was set at about 155 in 1999 when I built the garage and has never changed.

These problems with the epoxy are always caused by one of the following:
Air pressure at wall to low.
Air pressure at gun to low for size of tip. Bigger the tip more air needed to do the same thing.
Water in line.
Wax and grease remover still in pores.

You can dry spray like some people do but when i test each batch, I lay the first coat like my last coat of clear, so you will never hear me say you sprayed it to wet.
 
i've had a few issues but i am using a big gun. i've learned to crank up the air on the 2.3. shot the other day and left it at about 30 and had some craters but not many.
 
Interesting...I'm using a 1.4 tip on the Iwata...after the W&G remover, I let it sit for I'd say maybe close to an hour...and yes, I spray it on wet also.
 
That only leaves air pressure and wall pressure for you.
Nothing else.
 
shot some today crater free. i think barry is right on the problem. up the pressure and see what it does.
 
I will try that this weekend and let you know...thanks for all the help !
 
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