Need some help with UV clear

AAE;n83794 said:
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.
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Temperature cycles aggravate the issue as the air inside contracts and expands, drawing in new moist air with each cycle unless the can is 100% sealed which is difficult to achieve. The more empty the container, the greater the problem. Storing at a constant temperature helps considerably.

Don
 
rustover; I seriously doubt it's in your lines. Most likely cause is airborne contamination. Like Crash said any sort of silicone spray will stay in the air a long time. I have also seen diesel fumes do the same thing. If there is a diesel truck in the vicinity especially if it's a dirty one, it will cause those fisheyes.
 
another possibility is your mixing cups. about 8 years ago i went though this situation and after going a couple months of spraying and trying to figure out what it was i came down to mixing cups that had some sort of in them. my situation gave me the exact same results as you. clear only BUT the fisheyes i was getting were much worse than what i am seeing in your pic.

diesel truck.....ehhh i have heard people say that before but since i have been running a diesel fired heater in my booth for probably 12 years now and never had a single fisheye from it i would say thats a myth. i have even had it flame out numerous times and blow white diesel smoke all over the booth when i had the fan off. i went in and did another round of clear and still not a single fisheye.
 
Jim C;n83801 said:
another possibility is your mixing cups. about 8 years ago i went though this situation and after going a couple months of spraying and trying to figure out what it was i came down to mixing cups that had some sort of in them. my situation gave me the exact same results as you. clear only BUT the fisheyes i was getting were much worse than what i am seeing in your pic.

diesel truck.....ehhh i have heard people say that before but since i have been running a diesel fired heater in my booth for probably 12 years now and never had a single fisheye from it i would say thats a myth. i have even had it flame out numerous times and blow white diesel smoke all over the booth when i had the fan off. i went in and did another round of clear and still not a single fisheye.
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Jim I know what you are saying cause we use a diesel fueled auxillary heater as well. Don't have any issues with it. But when I was at another shop I kept having random issues with fisheyes, Really weird stuff seeing as how I knew I was getting everything clean and I never would have an issue with contamination. This was an old stye crossdraft booth and the intake side happened to be right next to where a delivery truck would stop when they delivered parts. Couldn't smell it in the booth but everytime that truck came into the parking lot I would have issues. Once I realized this I would shut down the fan until the truck was gone, never had any issues again.
 
Maybe that truck was burning a lot of motor oil? I remember once I had a job just frickin' explode on me in the middle of the second coat. Turns out one of the lot boys was putting Armor All on the boss' tires well over a couple hundred feet away. Scary how far it went and how it got past the filters so easily.
 
Guys I sprayed it this morning again with the new activator. Same issue. This time they are worse. I also put a new motor guard filter on the gun. Im just not sure. I will let it cure until tomorrow evening and then sand it again. I also tried bumping the pressure up and it seemed like they got smaller. I went from 29 psi to 32. I just don't know what is causing them. I never had any trouble with the primers. This time I did take some left over clear after the second coat and fill all the ones I could see. I know I missed some.

Could it be a pressure / volume issue? The compressor sits in another building, about 40ft of line and Im using a 35ft air line to spray with. The compressor cycles at 90-135psi and I use a regulator at the gun.

I totally cleaned the shop this time. I'm just not sure.
 
Blow just shop air through a very clean white towel for a few minutes and see if the towel has any visible moisture or residue on it.
 
crashtech;n83842 said:
Blow just shop air through a very clean white towel for a few minutes and see if the towel has any visible moisture or residue on it.
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Just did the test and it looks fine. I also put some water in a new mixing cup and spray air into it to see if I could see a sheen and it looks good to. I used my gun to spray the air with that I was using for the clear.
 
Given your setup, I have to believe your ambient air is contaminated somehow. Problems like this can be notoriously difficult to sort out. I worked in a shop temporarily where every single job had to have fisheye eliminator put in it. Nobody knew why, nobody was doing anything wrong. It was horrible, and I was relieved to get out of there.
 
crashtech;n83846 said:
Given your setup, I have to believe your ambient air is contaminated somehow. Problems like this can be notoriously difficult to sort out. I worked in a shop temporarily where every single job had to have fisheye eliminator put in it. Nobody knew why, nobody was doing anything wrong. It was horrible, and I was relieved to get out of there.
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Thanks Crash I agree. I don't think this is going to be easy to find. I have been racking my brain suspecting everything. I'm going to sand it again but not clear it until I can get my practice panel looking good. I will use process of elimination and try to find it.

My first coat on both attempts is really wet. Is it possible that I'm putting too much material down on my first coat.

I will set my practice panel up outside and make a pass and see what happens. It shows up on the first pass. I'm using my prolite, but may try my lph to see if its any change.

Thanks again for the advice.
 
Fisheyes have less of a chance to cause big craters when the coats of material are less heavy and/or mixed with faster drying activators/reducers. If you can get it so that there are a manageable number, you can drop clear into the holes and use a block to color sand them flat later. Since this seems to be happening on the first coat, your panel cleaning methods may be suspect as well.
 
Rustover,

I have to ask this just to say I did......when you quote gun pressure numbers, I assume you do mean it is a working pressure with the fan adjusted and the trigger fully pulled in? Sorry to have asked but it's one more variable to rule out, of my mind at least, when trying to figure out what is causing the apparent fish-eyes. Also, are you wearing a painters outfit to avoid possible clothes contaminants?

Mike
 
rustover;n83848 said:
My first coat on both attempts is really wet. Is it possible that I'm putting too much material down on my first coat.


Thanks again for the advice.
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No, it doesn't matter how you put the clear down if your getting fisheyes you are going to get them until you can figure out what is going wrong. Have you waxed or used silicone on anything in the area? Even silica sand/dust from sand blasting will give you fisheyes.
 
MikeS;n83853 said:
Rustover,

I have to ask this just to say I did......when you quote gun pressure numbers, I assume you do mean it is a working pressure with the fan adjusted and the trigger fully pulled in? Sorry to have asked but it's one more variable to rule out, of my mind at least, when trying to figure out what is causing the apparent fish-eyes. Also, are you wearing a painters outfit to avoid possible clothes contaminants?

Mike
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Yes to both Mike. Thanks.
 
DATEC;n83855 said:
No, it doesn't matter how you put the clear down if your getting fisheyes you are going to get them until you can figure out what is going wrong. Have you waxed or used silicone on anything in the area? Even silica sand/dust from sand blasting will give you fisheyes.
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No on the silicone that I know of. No tire dressing stuff or anything like that. I built this area just to spray in about 5 years ago. I live in the mountains so I will take a test panel outside in the back and make a few passes and see what happens.
 
crashtech;n83852 said:
Fisheyes have less of a chance to cause big craters when the coats of material are less heavy and/or mixed with faster drying activators/reducers. If you can get it so that there are a manageable number, you can drop clear into the holes and use a block to color sand them flat later. Since this seems to be happening on the first coat, your panel cleaning methods may be suspect as well.
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Thanks Crash. I have been using the solvent w/g remover. I'm wondering if I should use the waterborne. I usually just use it on bare metal. Next time I practice with the trunk lid I will clean it really good. I usually clean until nothing shows up on the towels, but when cleaning the sanding the clear nothing really shows up anyway since Ive already washed the panel. Also I didn't use any directly on the base. I figured it was already clean. I did use the surgical blue tack cloths and I still wonder if I'm using those wrong. Next time I practice on the trunk lid, I'm going to skip the tack cloth and see what happens.
 
Rust, a good course of action on cleaning is to use waterborne first. Spray it on the panel and wipe with a towel, prep wipe etc. Then use the solvent based, soak your towel, prep wipe etc. with degreaser and then have a second towel to wipe dry what your first one laid down. Make sure you have gloves on (nitrile or latex) when you do this. Failure to wipe with a dry towel after your solvent towel will leave potential contamination on the surface. Wipe everything that is to be painted. Seeing as how you are having trouble it wouldn't hurt to double your steps to make sure you have gotten everything clean.....meaning waterborne, wipe waterborne, wipe, solvent wipe, solvent wipe. Wear gloves and change your towels often. If you are not using dedicated prep towels your towels could also be a source of potential contamination as well.
 
I use 3M 7910 tack pads. I know everyone hates 3M but these things are fool proof and easy for the DIY guys.

I'm going to guess you are getting too aggressive with the tack rags you are using...

Don
 
Thanks guys. Chris I will definitely try the cleaning suggestions. I was just using the solvent and using one of those pump sprayers, then wiping it off. I'm going to try some testing with some old panels and see what happens. Seeing that it did do it immediately over my fresh basecoat I'm thinking of skipping the tack rag all together to see what happens. I will let you guys know. Thanks for all the help.
 
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