Fisheyes or Solvent Pop?

Guys I need your help-

I am painting over UV Clear with UV Clear-
I have had this happen 3 times in a row now, (on 2 different Fenders) where I am getting "Craters",
It is generally happening on the second coat-

I am using an LPH400, (silver cap) with 1-Motorgard M-30 filter and 2 Motorgard M-60 filters along with a dessicant filter at the gun-it is sanded to 600 grit, and then gone over with a red Scotchbrite-

This has happened with new UV Clear, and due to the shortage of UV Clear, I have some leftovers that are 3 and 4 years old (stored indoors), and I've used them (with new Activator)-

This last go around (after the first coat cratered), I mixed about 25% very slow SPI Reducer and sprayed 3 coats 15-20 minutes apart-it seemed better, but it's still a problem-

I'm very frustrated now (I bet I've gone through $3-400 of sandpaper on 2 Fenders) and am waiting on new UV Clear to become available-I have changed everything I can think of-no tack rag, no perfume or anything on me that is Silicone based-I use Waterborne W&G remover, and wipe it down 4-5 times with it, and let it sit overnight so that it is for sure dry-

I'm clearly out of my element, but in the past have had great results with SPI Paints and Clears-

What am I doing wrong?

35window said:

What am I doing wrong?

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Spending $300-$400 on sandpaper.

Fisheyes are either airborn, on the surface, or in your air supply. No fisheyes first coat pretty much eliminates surface. Airborn can happen at any time, but I would guess air contamination. Those filters you listed will not stop all water and oil contamination, unfortunately.

Anything with silicone in the room or adjacent room could be causing it. Tire or dashboard products maybe. Sometimes you have to look in places not normally obvious. What cloths are being used to clean with? I've heard the microfiber towels can have a chemical in the material that could cause problems. I don't use them so never had that problem. I watched someone at another shop use them to clean before paint. Yes, they were having some issues with their paint. Someone else may be able to help more.

What are you wiping down with? Meaning what type of wipe are you using? When does it occur? You mentioned second coat then first coat later. I'm with TK in thinking it is more than likely coming from your air supply, especially if your first coat is OK and you are not getting fisheyes when spraying sealer or base, it is more than likely water.
How big a compressor? How did you run your air lines? How far from the compressor to the regulator?

Thanks for your replies-
I wipe it down with the blue, Scott towels in a box, the Compressor is an 80 gallon single stage unit, I have 4 water drops in my steel air lines, and it is about 25' from my Compressor to my Regulator-

35window said:

Thanks for your replies-
I wipe it down with the blue, Scott towels in a box, the Compressor is an 80 gallon single stage unit, I have 4 water drops in my steel air lines, and it is about 25' from my Compressor to my Regulator-

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Ideally you want a minimum of 50 feet before your regulator. At 25 feet the air is still cooling and condensing water. Copper you might could get away with it but steel it will be still warm. That could very likely be the cause. Especially as you have no desiccant dryer. Even with a dryer, the lack of distance would render it ineffective. That little filter on your gun doesn't count. Better to throw it away. It is costing you airflow that you need to spray modern higher solids stuff.
You don't mention the brand or hp rating of the compressor, the cheap box store ones can contribute to the cause by being undersized and the compressor having to run more often. As a general guide a 5 hp, two stage compressor is considered the minimum to have.
Water condensing in the hose due to the lack of cooling before it reaches the regulator would be the most likely cause. It's really hard to give you an exact cause without being there and looking at things in person. Personally I wouldn't use those Scott towels as they are not a "clean" towel. But they are not as bad as some. Solvent pop would be the least likely cause IMO. Solvent pop craters are going to be small, whereas water will leave a larger crater. If you are piling on the second coat that could cause solvent pop but this time of year would be very rare.

Some general guidelines:

50 feet of distance between the compressor and regulator.

Three stage filtration in this order, water coalescer, oil coalescer, desiccant dryer.

Never use any products containing silicone in or around your paint area/Shop. This includes outdoors. Armor-All will stay in the air for days. It also will evaporate off of tires and contaminate things.

Use dedicated paint prep wipes and latex/nitrile gloves when wiping down. Read the thread on how to wipe down a car here on the Forum.


Try to look at your entire process looking for any chance of contamination. Most likely though it is an issue with water condensing down your line. Would be a good idea to run 25 more feet of line. Mandatory IMO. If you lack space you can run it up and down on the wall to achieve 50 feet. That combined with the correct filtering/drying would eliminate the water. If you do nothing else add the 25 feet and it will help eliminate a lot of the water. Keep your traps flushed often, along with draining the tank several time a day.
You could add a refrigerated dryer to your system but it would need to be at the end of the 25 feet of pipe. You can do a search here, keywords "refrigerated dryer" and get some good info on them and how to use one.

I'll add that running only those Motorguard filters you are going to need to change them often. If it is saturated it is essentially useless.

Book says three coats or over; wait 30 mins between coats. You said 15 to 20 mins.
99 times out of a 100 when the second coat is
Is due to spraying too soon.
If it happens on the first coat, it's contamination.

Curious what temperature and what speed activator.

Don

back off and put thinner coats on. my guess is flash time too short .

Barry,
The reason for the 15-20 minutes comes from your tech tip on how to cure Fisheyes-I have always waited 30 minutes between coats-
What is confusing is that this has never happened before and I have shot at least 10 gallons of UV Clear with this setup and have had 0 problems (unless, of course, you don't include the screw ups of the Painter )-
Yes, I change the Filters often, and the reason I bought 3 filters was that Motorgard claims they are designed for particulate, Oil and moisture down to 1 micron, so I thought 3 would do it-
Temperature was 75 degrees and very slow Activator-
Shine I'll try that but I'm very close to dry spray-

assuming this is the non low voc uv clear, i have been spraying that clear for over 20 years in all kinds of conditions and have done 2 coat jobs as well as 10 coat jobs at one time with anywhere from 5 min flash to 1hr flash between and i have never gotten that clear to solvent pop....ever. i even did a test panel many years ago, 14 coats with 5 min flash, fast activator, 95 deg day and 90%+humidity. no pop. i would almost certainly say that your issue is contamination of some sort. the 2.1 version and other spi clear i have gotten pop with those if abused. contamination could be coming from anywhere. be sure your using real mixing cups as well. i had this issue once before and it came from my cups. they must have all been contaminated. it didnt show up when spraying primers or base, just clear.

Barry said:

Book says three coats or over; wait 30 mins between coats. You said 15 to 20 mins.
99 times out of a 100 when the second coat is
It is due to spraying too soon.
If it happens on the first coat, it's contaminat

Click to expand...

35window said:

Barry,
The reason for the 15-20 minutes comes from your tech tip on how to cure Fisheyes-I have always waited 30 minutes between coats-
What is confusing is that this has never happened before and I have shot at least 10 gallons of UV Clear with this setup and have had 0 problems (unless, of course, you don't include the screw ups of the Painter )-
Yes, I change the Filters often, and the reason I bought 3 filters was that Motorgard claims they are designed for particulate, Oil and moisture down to 1 micron, so I thought 3 would do it-
Temperature was 75 degrees and very slow Activator-
Shine I'll try that but I'm very close to dry spray-

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Im confused here; fixing fisheyes is not used much procedure and done with fry coats longer set times than a wet coat.

If doing ins work, we never do more than two coats, so yes, 5 to 15 mins are the norm between coats.
If three or more coats always we have said for 20 years 30 mins between all coats.
We know 9 out of 10 times if fisheyes show up on 2nd or 3rd coat its solvent pop from ruching and depending on the amount of solvents, can be the smallest pinhole to looking like a baby fisheye.

Maybe it is contamination; I am not sure
But we can eliminate one thing at a time.

Thanks to all, I appreciate your time & thoughts-

I'm going to eliminate anything that I believe to be remotely responsible-

Everything I have used on this Car (after SPI) was Chemical Guys products (compounds, waxes,Glazes, etc.--

I'm sure there is something with Silicone in it, but the last time I used it would have been at least 5 months ago-nonetheless, I have used Waterborne W & G remover everywhere (more than once), and I'm going to pull the wheels as I used a tire product that no doubt has Silicone back then-

I'll replace all the Filters again, buy a new air hose and try again-if that doesn't work, I will replace my Compressor, as I'm not sure what else to do-

I've never used a Fisheye additive, and am reluctant to try it (I'd rather fix the problem)-

Before you break the bank, just an idea!!!
Was this painted over fresh clear that had not been in the sun??
When you do it again, sand till perfect and give it a day or two in the sun to remove solvents.

I tried to get Chemical Guys to give me a list of products that didn't have silicone, because I don't want anything around, and the only product they offered me was Nonsense cleaner. I assume everything else had silicone, because they would not say otherwise. They are geared towards detailers, not bodyshops. Do not use a fisheye additive.

i keep tooth picks in my booth . from time to time i will experience craters . i use the tooth pick to put a drop of clear in the crater . problem solved.
usually there will be several on a roof or hood . most likely from painters brain fart .

i've used CG for over 30 years . never had a problem. i do my buffing in the booth so if there was silicone in it my booth would be destroyed.

just a thought, if your wiping with 700 before you spray even though everything seems dry there can be moisture left in the surface. You really need to give the 700 some time to dry before spraying. Could need 15 min, could need over an hour depending on conditions and airflow. Also not sure at what point in the process your using the 700.