clearcoat dots

MSS3020

Well-known Member
painting a new tailgate for my f250. When I sprayed the clearcoat..the first two coats were fine.. wait about 10 minutes for recoats.. on the third time over there were hundreds of little dots which look like crators in the clear coat??? I have two water filters on my air. one on the tank as the hose leaves the tank the other on my gun..??? What happened.. I am using a gravity fed gun...Also I know this isnt in the paint because this is the second attempt at clearcoat.. the first I had couple runs so had to wet sand using 1500 the gate so this is a reply..
 
It sounds like the last coat you didn't thin the clear enough and you got pinhole blisters. Without seeing it, it would be difficult to guess what it might be. If you used a rag or sandpaper that was contaminated with silicone it might be fisheye but that would make larger holes in the finish.
 
pinhole blisters???? I havent been using any reducer in the clearcoat just activator.. The first clearcoat attempt was with the tailgate at vertical this time laying flat.. also temp was about 65 first try this time was 80ish..The clearcoat is a 4-1..clear-activ. how much reducer would I want to add to this... It flowed together really nice to except the holes..
 
solvent pop. depending on which clear you use, generally one medium coat of clear and then one medium wet coat. the solvent from the first two coats is trying to escape thru the 3rd coat. gonna need to sand back down to remove the craters, and you will prolly end up thru the base coat too. if you do, you will need to shoot the base again, then clear. also if your temperature is too hot, the clear will solvent pop also.
 
Are they bumps (uppies) or are they craters (downies)?? If they are uppies then they are solvent pop for the reasons allready stated below. If they are craters then they are fisheyes caused from air contamination. I once had a problem with that and only on the second coat of clear , first was perfect. Cleaned everything for a week and finally looked on the container of deoderant/anti-perspirant I used and there in black/white was the ingredient "silica". When I reached over the panel to paint , my shirt , which was saturated with it because silica doesn't wash out , was obviously shedding some in the wet 1st clear cote and reacting in the second. I changed deoderant and wore a disposable paint suite and havn't had the problem since. It wasn't the first I had heard of this and that is why I checked my deoderant in the first place.
 
What I'm calling pinhole blisters is what others are calling solvent pop. In general if you spray on a finish that is too thick it skims over the surface and builds up solvent fumes underneath like a carbonated soda and when the bubbles go through the skim surface leave a hole in it. You need to refer to the specifications on the finish you are using for the thinning. Even though it's just a starting point. Sometimes in different conditions you might need less thinner or more. It might help if you posted the specific product you are using so someone could give you better advise. From where you are unless you have hundreds of holes you could dab some clear on the spots with a toothpick, let dry and sand level, but you would need to put another coat of clear over it. If there is hundreds of holes then you might thoroughly sand the clear and put another coat or two of clear over it sanding between coats. Just when you are sanding if you see any color in the sanding stop, you've gone through the clear.
 
I re read your post a couple of times and realized you shot base, then clear, then sanded a run out and re shot 3 more coats of clear? How much time between applying the first clear and the last coats? Way too much clear,
 

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