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What went wrong?

#1
I painted the underside of a decklid the other day with Nason Fulthane single stage urethane and didn't get the smooth glossy look I'm used to with the this paint. Instead I got a dull looking finish with a very fine texture to it (not orange peel - finer than that) and a LOTof debris in the finish. I usually seal my work with SPI epoxy but I didn't have any left in the color I wanted to use so I sealed it with thinned down 2K primer that I lightly sanded with 500 grit and then cleaned with SPI waterborn cleaner and let sit for several hours - then I tacked the whole thing off right before spraying. I sprayed two medium light coats then one or two medium wet coats to level out the finish. It was very warm in the paint area.

I mixed the paint 8-1-2 (I used medium reducer to try to speed things up since I was spraying such a small area) like I always do and strained it before spraying so I'm at a loss where all the debris that ended up in the paint job came from (there was big chunks of it), although I'm almost positive it came out of the gun. The hardner I used was probably getting towards the end of it's life but it still poured freely into the mixing container. Also the SPI wax and grease remover I used (that was given to me by someone else) had turned brown, so I've been wondering if it's still okay to use. I cleaned my gun out with gun cleaner several weeks ago so I suppose there's the possibility something is just now coming out of it that got loosened up by that that hasn't shown up until now.

Those are the only things I can think of that might have caused the problem, but I would appreciate any other thoughts on the matter on more things I might need to look into to improve my results in the future.
 

Barry

Paint Fanatic
Staff member
#2
All sounds good my guess is just was hotter than normal and the medium reducer was too fast.
Needed slow.
 
#3
I'm a slow learner but a fast forgetter(Barry would agree). But, the one thing I have learned is that if you go to a speed slower than you think you need, you'll have much better results.
 

elwood

Registered Users
#6
The trash could have came from all those places that it likes to hide under the skeleton/braces. Just when you think you've got all dirt gone, it shows up after spraying starts. Hoods and decklids are the worst for those surprises.
 
#8
The trash could have came from all those places that it likes to hide under the skeleton/braces. Just when you think you've got all dirt gone, it shows up after spraying starts. Hoods and decklids are the worst for those surprises.
I agree with that but I think this time it might be different though. A lot of time when I've been painting lately I've been getting trash in the paint that seems like it can't be coming from anywhere else but the gun. It helps a little if I use an in the gun filter, which makes me think my paper filters aren't doing their job. I try to store them somewhere where they don't get dirty, so either they don't have a fine enough mesh or they picked up dirt at the paint store.

I also have been straining the thinner I use to clean my gun with after spraying to solve this dirt problem.
 

Chris_Hamilton

Trying to be the best me, I can be
#9
I agree with that but I think this time it might be different though. A lot of time when I've been painting lately I've been getting trash in the paint that seems like it can't be coming from anywhere else but the gun. It helps a little if I use an in the gun filter, which makes me think my paper filters aren't doing their job. I try to store them somewhere where they don't get dirty, so either they don't have a fine enough mesh or they picked up dirt at the paint store.

I also have been straining the thinner I use to clean my gun with after spraying to solve this dirt problem.

Triple or quadruple your strainers. Wipe them in and out with a tack cloth before using. If you think it's from the gun make sure you break the gun down completely and clean it meticulously. Spotless. You do that and still have trash you have eliminated those two possibilities. As was said above 90% of your trash issues comes from what you are painting. Undersides of hoods and trunk lids are notorious for being difficult to get all the debris from underneath the braces out.
 
#10
Yeah, the insides of parts just keep giving up dirt. I've blown out bracing for what seems like forever and there will still be something coming out.

Also it might have been hotter than you thought. Sometimes when it's too hot for a product we'll naturally try to hammer it on wetter, which can create what I think you are seeing, which is probably dieback.
 
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