Gun routine with Epoxy

aviator8

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Well I just learned a hard lesson and wasted a bunch of time so I'm going to ask what the routine is that others use. Yesterday I had prepped several chassis parts to spray in black epoxy. After getting everything all dialed in I did my spraying. The pot life on the epoxy is 72-120hrs. I needed to do another coat and thought that in a sealed PPS system the epoxy would not cook off and would be fine overnight for a second coat today. When I went to dial in my pattern nothing. What I did not anticipate was that the solids would settle out into the gun. I had to clean all that out and ditch what was left of my mixed epoxy since most of the solids were now in the trash. Now that I have learned the hard way to not do that, what is the routine others use?

Remove and tape the cup?
let it sit attached but upside down then mix?
others?
 
Never leave the epoxy in the gun for more than a couple of hours.
Years ago, I left it overnight, and the pigments settled, and the gun would not spray had to take the gun apart to make a passway and put it back together, and shoot thinner to get the rest of pigments out.
It did not kick just settled as is normal once activated.
 
I have a question that goes along with this. So if the pot life is 72-120 hours, does that mean the sprayed epoxy is also not cured until after that amount of time? When allowing the epoxy to sit around that amount of time, will you need to add any type of reducer to maintain its spray-ability?
 
Gel time and cure are different aminals.
Complete cure sprayed is about 90 days.
A lot of factors are related to curing as well as
How long is still good in the cup.
I've had cups thicken in 48 hours and once sprayed it at the exact 7-day mark.
The rule of thumb is if it needs thinner to spray, the time has run out.
 
When I spray two or three coats of epoxy, ( waiting an hour between sprays) I run thinner thru the gun until it pee's clear after each spray. It only takes 5 minutes, if that, and the spray gun is good for the next spray. Once I'm totally sprayed out with epoxy, then I'll disassemble the gun for a complete cleaning.

Knock on wood, I haven't had a problem yet.
 
When I spray two or three coats of epoxy, ( waiting an hour between sprays) I run thinner thru the gun until it pee's clear after each spray. It only takes 5 minutes, if that, and the spray gun is good for the next spray. Once I'm totally sprayed out with epoxy, then I'll disassemble the gun for a complete cleaning.

Knock on wood, I haven't had a problem yet.
same here but since I use DeKups I always have one cup 1/2 filled with SPI reducer and after a coat of epoxy, primer, base or clear I pop off the one with product, pull trigger ’til empty then put on the one with reducer. One or two trigger pulls and gun is clear enough until ready for next coat. Last coat get same treatment plus a full breakdown and cleanup with lacquer thinner and brush etc.
 
So my now adjusted routine is to spray. If I am going to recoat fairly quickly I will let it sit and give it a quick agitate to get pigments in solids redistributed. If I need to recoat later, pull the cup and tape the top, thinner through the gun. the next day a good swirling before back on the gun. Once finish teardown and clean.


Also I have a question about the epoxy. Most refer to it having a satin or semigloss finish. My cloats are all coming out more on the gloss side. If I am spraying a little too far back from the peice or have the gun adjusted for less trigger pull I get the satin like finish. The tech manual called for 2-3 wet coats, am I laying this on to thick? I did get a thick coat and had the fisheye issues, which I corrected, but I would prefer satin to gloss.
 
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same here but since I use DeKups I always have one cup 1/2 filled with SPI reducer and after a coat of epoxy, primer, base or clear I pop off the one with product, pull trigger ’til empty then put on the one with reducer. One or two trigger pulls and gun is clear enough until ready for next coat. Last coat get same treatment plus a full breakdown and cleanup with lacquer thinner and brush etc.

I thought about doing it your way, it's a sure way of a quick cleaning. I use the 3M PPS 2.0 cup and liners and the adapter allows me to take the cup off, fill the adapter with thinner. I do that 3 times and the gun is ready to go for the next round in an hour.
 
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So my now adjusted routine is to spray. If I am going to recoat fairly quickly I will let it sit and give it a quick agitate to get pigments in solids redistributed. If I need to recoat later, pull the cup and tape the top, thinner through the gun. the next day a good swirling before back on the gun. Once finish teardown and clean.


Also I have a question about the epoxy. Most refer to it having a satin or semigloss finish. My cloats are all coming out more on the gloss side. If I am spraying a little too far back from the peice or have the gun adjusted for less trigger pull I get the satin like finish. The tech manual called for 2-3 wet coats, am I laying this on to thick? I did get a thick coat and had the fisheye issues, which I corrected, but I would prefer satin to gloss.

You really should quick clean your spray gun if you're applying two or more coats of epoxy. If you're following the recommended flash time for epoxy ( 45 minutes ) you have a good chance of your spray gun having epoxy build up if you don't do a quick clean. Since you're using the PPS system, simply take the cup off and cover it. Fill your PPS adapter with thinner and let it pee out. I fill mine three times. I guess it wouldn't hurt to simply spray the thinner out from the adapter. I let it pee giving the slow movement of the thinner a chance to do it's job. When you're done for the day, tear the gun down and clean it. It really doesn't take much time, maybe 10- 15 minutes depending on how anal you are about your equipment.

Take care of your equipment and it'll take care of you.
 
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Also I have a question about the epoxy. Most refer to it having a satin or semigloss finish. My cloats are all coming out more on the gloss side. If I am spraying a little too far back from the peice or have the gun adjusted for less trigger pull I get the satin like finish. The tech manual called for 2-3 wet coats, am I laying this on to thick? I did get a thick coat and had the fisheye issues, which I corrected, but I would prefer satin to gloss.

I'm using Black epoxy at the moment. It does have a very nice gloss finish when first sprayed, however, by the next day or so, the gloss will fade leaving a satin / matt finish
 
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When using the PPS paint cups, do you guys remove the strainer built into the lids when spraying the epoxy?
 
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I recently bought the DeVilbiss cups but haven't used them yet.
When spraying epoxy, I return whatever remains in the spray gun back to the cup and rinse the spray gun with lacquer thinner until it runs clear. It really doesn't take much or very long to do.
Before refilling the gun, I stir the epoxy in the cup first and always use a strainer when filling the cup.
 
I leave "NO" material in a spray gun between coats. With RPS cups-dump back into the cup, remove the lid/cup from the adapter and place an extra cap on the lid. Then it's easy to rinse the head of the gun with thinner. Restir the material before placing back on the gun and spraying.
Simple to do and never any problems.
 
i rinse the nozzle between coats .
 

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Is that just a ketchup squeeze bottle? Would be handy but wont lacquer thinner melt it?

 
i bought a case of them from Taps . use then for air brush colors and many other things. wont melt.
 
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When using the PPS paint cups, do you guys remove the strainer built into the lids when spraying the epoxy?

Yes, remove PPS cup lid screen/ strainer when spraying epoxy. Also do not use an internal gun strainer when spraying epoxy,
 
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