Production Clear: Minor solvent pop?

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ebaypdllc

Promoted Users
Been using the Production clear with a lot of success so far. I'm using the turbine sprayer and i'm getting really nice results which i'm super happy about but i'm still not at 100% where I want to be.

I was getting some solvent pop, real minor using the production clear with "slow" activator. I bought the "very slow" hardener last week thinking that would solve the problem but i'm still getting it.

Its very minor. If this was on a bumper etc I don't even know if you would see it. Its because i'm painting small products and examining under LED lights that I look for the smallest imperfections. The solvent pop is minor, I can't even get it to come out on picture. Its just enough to where I have to wetsand and buff to remove which I would like to eliminate the step.

It appears mostly if I get a sag or a run, usually about 2 1/2 to 3 hours into the curing process. It also happens all over the part, but very minor. It easily wetsand and buffs out.

I'm in a climate controlled area 70 degrees but the makeshift booth I paint in I wet the concrete floor. I also wet the plastic walls down.

The problem I believe is the turbine is likely making the clear skin over too fast but Barry recommended I add Retarder to my mix which is the next step i'm going to try.

I spray a coat, wait about 25-30 minutes then spray again. I also tried spraying only 1 wet coat, results were the same. I also turn the booth fan off.

My question is, how do I use the retarder. I mix small amounts of clear usually, 150 grams of clear, 37.5 grams activator. I'm going to start out trying 5% retarder... is that to the total mix? 150+37.5 x .05 = 9.375 grams?

How does the retarder alter flash times and overall cure times? I'm assuming adding more changes the curing cycle?

Here is a shot of how nice the turbine lays out the Production clear with .8mm tip at 7 PSI.

Thanks for your help again with everything.
 

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Normally solvent pop occurs on 2nd or later coats and is always a result of not enough flash times between coats BUT you pointed out it does the same on first coat so that means everything is out the window except the gun.
You answered the problem your self with the adding of retarder, should not take much so I would start with a cap-full (cap on retarder can) try and do a second capful is needed.
You are about there and as far as the retarder total cure til sanding in a matter of a few minutes difference, remember slower is faster.
 
I am a little leery of the arithmetic on the weighing of the material. It's not harmful to assume that the ready-to-spray clear has the same specific gravity as the retarder, but it might throw the mix off a little to assume the activator has the same specific gravity as the clear. My measurements of Euro clear showed that the activator was around 13% more dense than the clear, so mixing 4:1 by weight would result in over-activation. I can't speak to Production Clear, though, as I have never used it.
 
Hey Crashtech. Yeah alot of people don't understand specific gravity.

I go to the dollar store and buy these 1 ounce shot glasses. Not sure if they are exactly 1 ounce but I fill them all the way up and weight them. The clear for production was 41 grams and the hardener 46. So its pretty close. Since I pour clear first before hardener. I divide 46/ 42 = 1.095. I then divide the 1.095 by 4 because its a 4 to 1 mix = .2738.

So if I pour out say 100 grams of clear, I then times that by .2738 which gives me 27 grams of hardener. So its pretty close when measuring small amounts when doing the weight mixing.

I will have to weight out the retarder to get the specific gravity.

I know basecoat PPG DBC and reducer were nearly identical with weight also.

The SPI epoxy I weight comes out at 56 Grams for Epoxy and 38 for Hardener. So if you do Hardener 38 / Epoxy 56 = .6785

Epoxy 100 grams x .6785 = Hardener 67.85 grams

Thats how I do my mixing by weight...Well I hope its right LOL.

Below is a pic of the SPI Epoxy in shot glass I saved on my phone.
 

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Don't over think it. Just add small amounts until you get close. Conditions are never the same.
 
This is not rocket science. You really have no reason to do it that way you are wasting alot of your time trying to reinvent the wheel.

If it was that important Barry and the guys would have already done the work for you.
 
Reinvent what wheel? It's basic high school math, might even be grade school math to mix something by weight. It's also easier...

And all I did was ask simple solution to get rid of the ever so slight solvent pop I'm getting. Never used a retarder before and there is limited information available. That's point of these forums, to share information to help others.
 
Please don't get offended. The fact remains that conditions change all the time. Maybe your base isn't flashed off. Maybe your putting the clear on too heavy. Maybe wetting things down is causing the skinning over. Have you checked the temp if the air coming out of the turbine? If its hot and causing the clear to dry as it exits then that will cause the skin. Barry always says to abuse his clears. Get crazy and use two caps of retarder. What's the worse that can happen?
 
@ebaypdllc

The weight example in your original post gives the clear amount as 150g, and the activator amount as 37.5g, which is incorrect. If we presume your measurements are accurate enough, the correct amount of activator for 150g of Production Clear would be approximately 41.1g, not 37.5g. That is why I said that I was leery of the arithmetic, not because I didn't understand, but because it was obviously wrong.
 
I would start with a cap full of retarder per mixed cup at first and see what happens, still pops use two the next time, get runs make the next one with 1.5 cap fulls per cup and watch your technique and flash times, your technique and flash times will have to be adjusted immediately when you use a retarder because what you are using will act differently.

To go buy weight is virtually impossible and unrealistic.
 
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