Where to go from here? Moisture pimples

A

akara

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Hello everyone, I am a novice first time painter. Painting my little Datsun in my garage.
I painted the car with 2 coats or so of SPI base, got dirt in it, wet sanded the dirt out with 800 grit, and did 2 more coats of SPI basecoat this time with the fan off, waited till the next day, then followed up with 3 wet coats of SPI Universal Clear.
It looked fine for me the first day, small amount of dirt and some orange peel but nothing bad.
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Next few days it developed dieback and pimplies from what I suspect was moisure in my airline and a wet floor. and I think the dieback is from 4 coats basecoat?

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I had installed a new dryer filter ive never used before and sprayed with it, and It was only 5 micron, and I wet the floor as well. my mistake. I had a problem with moisture in a paintjob I did before and it turned into white dots after a month in the sun.
Whats the best course of action from here? How long do I wait to correct this? There are 3 coats of UV clear, can it just be cut out after some time? It is going to be cold and wet here in a months time. Should I attempt to respray?

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I am not sure it's not solvent pop, the dots are very small but cover the entire car. It didn't appear as bad till the next day.
Medium reducer in base sprayed at 70f 30 min between coats, 24hr later medium activator in universal clear, sprayed at 72F 30 mins between coats.

I am afraid to try buffing them out to only have them return later
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How deep are those? It looks like contamination. If it was me, I'd use some powder guide coat and see how well they'd sand out. Start with a finer grit(1k) and see what happens. If you have a thickness gauge, use it to measure how much you're taking off. If not much is being removed, try 600 grit. It would be great if the universal could be a barrier coat then a couple coats of base( if needed) then 4 coats of clear. Use the slowest additives you have.
 
First important thing to do full sun for 4 or 6 days; temp dont matter, just the bright sun.
Do not wet sand and buff before.
It is co2, and after sun 1500, wet should get rid of them and then buff or go higher with wet sanding grits, your choice.
 
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Barry said:
I should add heat from buffing now can bring more out.
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Thanks, that's what's I was most concerned about. It's very overcast for the rest of the year here in Seattle, how long should I let it sit outside before buffing if it's cloudy?

I think having my gun at a low PSI also contributed. I sprayed at 18psi near what iwata says, instead of the 25-28psi people here seem to use.
How can I reduce the likelyhood of CO2 bubbles appearing in these 70% humid conditions? Should I be doing the clearcoat without stopping between coats?
 
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tried spraying the hood and trunk, because I was pretty sure it was a moisture problem. I added a coalescing filter and desiccant system after my water trap, and upped my gun pressure to 25 psi, wall at 130psi. It never drops below 100 at the wall.

I let the spi base flash for 24 hours, sprayed 4 coats of UV clear with Med activator 45 minutes between each coat at 68° temp, 68% humidity. no wet floor this time. lph400 fluid 2 turns out moving pretty fast 4-5" away, 50% overlap, doing thin coats watching for the clear to just fill in.

still having bad micro cratering after an hour or two of curing.. I'm having a hard time figuring out this UV clear. Appreciate any advice or ideas what I do wrong.
 
akara said:
tried spraying the hood and trunk, because I was pretty sure it was a moisture problem. I added a coalescing filter and desiccant system after my water trap, and upped my gun pressure to 25 psi, wall at 130psi. It never drops below 100 at the wall.

I let the spi base flash for 24 hours, sprayed 4 coats of UV clear with Med activator 45 minutes between each coat at 68° temp, 68% humidity. no wet floor this time. lph400 fluid 2 turns out moving pretty fast 4-5" away, 50% overlap, doing thin coats watching for the clear to just fill in.

still having bad micro cratering after an hour or two of curing.. I'm having a hard time figuring out this UV clear. Appreciate any advice or ideas what I do wrong.
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Post a pic of the microcraters.
 
dhutton01 said:
Post a pic of the microcraters.
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it's really hard to get them on camera without a microscope so I'll have to order a little microscope for my phone camera and wait until that arrives for better pictures but here is some I was able to take. It just look like little white dots but if you spend some time to look really close they're craters. Ignore the dirt nibs, those don't bother me.
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Here's a few I managed to snap tonight, little craters with bumps in them. Would having more airflow help stop this? or less flash times?
Video:




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akara said:
Sprayed my hood and trunk at 25 psi, wall at 130psi, iwata LPH400, temp 68 degrees, humidity 70%
This time I added a coalescing filter and fresh desiccant system after my water trap, made sure the trap and tank were empty of water, and did not wet the floor, and no wet sanding took place.
Did 4 coats of UV clear with med activator with 45 mins between coats, moving pretty fast with the gun, 2 turns out on fluid, not pounding it on.
Still having all the microcratering show up after 2 hours.....
Not sure what I am doing wrong here? Didn't have this issue with my other brand HS clear I was using before SPI. I know it's something I am doing wrong. Feeling a bit discouraged.
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Im sorry just saw where it says I deleted it, and if it did was an accident.
 
@Barry Could you explain CO2 gassing a little more? I've never had it happen and wonder how does it happen and what are some of the causes?
 
Whitesnake said:
It’s amazing how you can try and do everything right and use top of the line everything and have issues. Then when doing something you really don’t care how it comes out, cut all sorts of corners, cheap materials, etc they come out perfect lol. Never fails.
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Yes!!!! I spray stuff for interior pieces or steering column stuff and don't even clean the room first sometimes even spray it outside. And comes out fine. Lol
 
akara said:
Hello everyone, I am a novice first time painter. Painting my little Datsun in my garage.
I painted the car with 2 coats or so of SPI base, got dirt in it, wet sanded the dirt out with 800 grit, and did 2 more coats of SPI basecoat this time with the fan off, waited till the next day, then followed up with 3 wet coats of SPI Universal Clear.
It looked fine for me the first day, small amount of dirt and some orange peel but nothing bad.
View attachment 22785


Next few days it developed dieback and pimplies from what I suspect was moisure in my airline and a wet floor. and I think the dieback is from 4 coats basecoat?

View attachment 22786


I had installed a new dryer filter ive never used before and sprayed with it, and It was only 5 micron, and I wet the floor as well. my mistake. I had a problem with moisture in a paintjob I did before and it turned into white dots after a month in the sun.
Whats the best course of action from here? How long do I wait to correct this? There are 3 coats of UV clear, can it just be cut out after some time? It is going to be cold and wet here in a months time. Should I attempt to respray?

View attachment 22787
Click to expand...
1600 or 2000? Love those little Fairlady roadsters! They completely outclassed the MG in handling and acceleration!
 
Chris_Hamilton said:
@Barry Could you explain CO2 gassing a little more? I've never had it happen and wonder how does it happen and what are some of the causes?
Click to expand...
We had a long conversation yesterday, and he is doing everything right, and the compressor filtration is set up perfectly.
I think the whole problem is the compressor, as it is a 30-gallon tank plumed from the basement to the garage 50 feet away and does not have enough SCFM, and the paint job is acting like a run.
The tin is overworking, sucking moisture, trying to cure the job, and when you sand the run, you find co2 pin holes in the center.
I think we agreed on 1500 and buff.
 
Dryers are pretty awesome. Even a hf one is great for the $$$. How come I can spray garbage clear with no issues. Does the quality make it more temperamental?
 
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