Need some help with UV clear

rustover

Member
Hey guys, sprayed some base/clear for the first time today. The sealer and base went good, but I had some problems with the clear. I sprayed the base and it had sat for about 5 hours, I tacked it off and sprayed the clear. My gun Tekna settings were 28psi 2.25 turns out. I had a trunk lid and the lid of the cover that I'm working on. I sprayed the first coat and I layed it down pretty slick but no runs. After a few minutes I checked on it and thought I had got a lot of trash in it. Come to find out it was a crater and it was just one in a certain spots but they were scattered across the whole panel. Almost looks like a solvent pop but its the first coat. Not sure what happen. I did put a second coat on the lid and but it didn't help. Now I'm not sure what to do. I doubt they will sand out, I'm guess I will have to sand the panel in 800 and try again. Let me know what you guys think. Thanks for the help.

The pics make it look good, but its not. lol





 
Could be. I have a 3 stage desiccant system. Drained everything and didn't get any moisture. I don't know. I guess I will try to cut the flat areas with 800 and scuff everything else with a gray pad and try again.

I put the first coat on really wet, could that have cause it?
 
Did you use a previously opened can of activator? That stuff absorbs moisture and it will create fisheyes like that when it does.

​Don
 
It was an unopened can but I have had it for a year, so that may be the problem. I'm going to order some new activator and try again.
 
I don't think desiccants will trap oils that are in an aerosol state. When you drain your compressor tank, how clean is the discharge? What does your filtration system comprise of?
 
Its an RTI Apache A204mi stage 1 and 2 and a devilbiss ct30 desiccant. Compressor discharge seems to be clean. I haven't really notice a sheen on the water. Compressor is located in the next building over about 40ft from the main spraying filters.

 
I'd be inclined to say they are fisheyes. Your compressed air setup looks fine. Most likely contamination of some sort, less likely using the year old hardener. Sand it down with 400-800 grit (whatever you are comfortable with,) personally I like 600 and reclear. Make sure you get every trace of the craters sanded out or you'll see them after you re-clear. Make sure to clean the panels well.
 
Thanks Chris. These craters are really deep. They showed up on the first coat and I did put a second coat on anyway on the lid to the cover. I guess that was the right thing to do. I'm almost thinking they all won't come out. I did one corner of the lid this afternoon and I got about 95% out. There are two in that corner that are really deep and I'm afraid to go any further on them. I started with 800 and got most of them out on this corner and then I ran over the area with a grey scotchbrite pad and that seem to help.

The trunk lid also has them and I only put one coat on it. This was just for practice so I didn't go any further. I started wet sanding it tonight with 800 and quickly hit the base before they came out. This gave me an idea of how deep the really are. I do have a silly question. If you get these, would it be wrong after the second coat has been sprayed to take an artist brush and dab some clear in the craters? I would think they would sand out easier, but may be not a good idea.

Tonight's progress,



The two that I'm afraid to go any further on:



Looking from the non sanded area into the sanded:



One other thing, I have replayed the events of yesterday over and over, let me run this by you guys. I had to do some base repairs to the bed covers lid due to a bug that got into it. The trunk lid was ok. The base repairs turned out good on the lid to the cover. I went to prep for clear and both panels had quite of bit of base overspray on them when I was tacking them off. I usually unfold the tack rag all the way and just lightly run over the panels tacking them off while blowing air over the panel. When I noticed there was overspray coming off onto the tack rag, I work the tack rag into the panels trying to get the overspray off and this could be where my contamination came from. I have been using this brand of tac rag and never had a problem but I did use some pressure just before clear.




Thanks for the help guys.
 
could be anything. just something floating around in the air and sat on the panel during that 5hr dry time. i have used those tack rags for prob 10 years and never got an issue. it doesnt look like you have a crazy amount of fisheyes. when i get some like that i let the clear stiffen up for maybe an hour then go back with some clear out of the cup an put a little dot in each crater to fill it then come back and sand and buff.
 
Thanks Jim. I did some research on the forum before using those and thought they were good ones to use. Good to know about adding the clear. I will definitely do that if this happens again. Thanks for the help. This is all new to me and a learning process.
 
Jim C.... I like that idea. Easier to sand the top off a high spot than sand the whole panel down to the crater. Need to remember this as it will probably come in handy.
 
How does a can of opened container get contaminated if its closed after use?
 
When there are that many fisheyes, it almost has to be the air supply or contamination of the surrounding air with something like a neighbor spraying Armor All or tire shine. If silicone containing products have been used in that general area to detail a vehicle, you may find that they are very persistent in the environment.
 
Thanks Crash. I haven't used any detail stuff in the garage. I've always been particular about that. There is another car over in the other bay that has been detailed a couple of years ago and has been washed a few times since then. I may pull it out in the drive next time. I didn't have any trouble with the primer / base.

Is there any good way to test my air compressor for contamination.

I have been saving for a new 2 stage that will be used just for paint. Hoping to have it by the end of the year.

Thanks again.
 
As a suggestion, I recommend using an in-line filter like the Motor Guard D-12 as good measure to catch any last remaining containment's before the air enters the gun.
 
Outlaw;n83789 said:
How does a can of opened container get contaminated if its closed after use?

The activator is activated by moisture in the air. As the liquid space is replaced with moist air, the activator will begin to degrade. There are aerosol products that are pure nitrogen that when sprayed into a can will displace the oxygen and help to prolong the product life. It should be used after each opening of the can.
 
I only use Surgical Blue by Datco and have NEVER had any issues with them. Others yes but not Surgical Blue.
 
Do you use the same hose for the spray gun that yo use for sanding and other air tools? Might be some oil from those getting into the hose. It doesn't take much.
 
Thanks guys. Mike I will definitely look into those filters. Bob, I have a dedicated 25ft hose and 35ft just for spraying.
 
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