Solvent Pop with Kremlin 10-14 Airmix (AAA) and conventional lacquer

[Nick Sorenson]

I had a rep demo a Kremlin 10-14 today. We sprayed regular conventional lacquer (non cat) and unless we just whipped over the piece with the gun we got solvent pop and BAD. So bad that a black test piece almost turned white with tiny bubbles. If I took it easy and shot a medium wet finish I got orange peel and less solvent pop but it was still there. Definitely an un-acceptable finish due to the tiny air bubbles/specks. It is definitely solvent pop that we were getting and I tested two different cans of lacquer on hand just to make sure it was not just one brand. ProMar by SW is a common lacquer and I figured it was designed for airless so it should spray fine. Not in my case.

I'm wondering if maybe these are designed with cabinet spraying in mind and not a piano top finish like you'd see on a glass smooth furniture piece. I have to have glass smooth. This means level sanding and buffing of course. But I can't even spray a wet flowing coat with the Kremlin. As a background the tip/nozzle is a 09-114. Maybe that could be part of the problem? I looked at the chart for oz/minute then measured what I'm getting out of my current rig and it looks like an 03 or 04 matches that volume better.

Curious if anyone has had luck with getting a mirror smooth level finish (not just coating pieces but a flat-level glossy finish) with an AAA spray rig?

[michael gates]

Of Coarse you can, sorry to hear your rep wasn't more knowledgeable. First, was it primed properly, no tip on, stick the wand in and start pumping through the gun until an even stream comes out and all the air is definitively out of the line.
Did you have enough lacquer in the pail that the pick up wasnt sucking air, it takes a fair bit since the pickup is angled. Thats what it sounds like happened.
Tip size was fine. was the pressure around 12-15 when triggered and 30-50 fluid pressure?

Did you thin the lacquer down, I know the rep will say you don't need to, and technically you don't, the kremlin will spray it but it does a much nicer job when you use reducer.

Maybe the lines weren't tight and it was sucking air somewhere.
Did you use a mil gauge to check how much product you were putting on, the Kremlins really put it on quick, perhaps you were getting more on than you thought.

Too much product usually causes solvent pop but air intrapment is air in the line or moisture. Was the humidity ok the day you were spraying?
Air entrapment looks like a white haze trapped under a layer of finish.
Did you guys go over it multiple times(2 passes) this will also cause air entrapment when the weather is humid.

[Michael Pyron]

this may not have been solvent pop...

when I first bought my Binks Mach1SL gun with a pressure pot I had the same situation and unfortunately I was under a strict deadline to get a project done...I was getting massive amount of bubbles in my freshly sprayed finish and these were immediate so I was pretty sure it was NOT solvent pop issues...I was able to spray the table tops by thinning my mix way more than I wanted and between that and dragging the stands to another part of the room (which jiggled the freshly sprayed tops and essentially helped pop the bubbles) I was able to get a good finish...

in the end I found the problem was the brand new gun had some failing internal seals which was causing bubbles to be sprayed into the finish..when that was fixed the system sprayed an awesome finish...

solvent pops appear a while after the finish has been sprayed and there is time for a reaction between the new coat and previous coats

[Steve Jenkins]

I have been using a Kremlin for about 10 years now and love it. When you first start up and get the line purged attach the air cap and with the air turned off increase the fluid pressure gradually until you get a pattern with horns on the ends. You can see this just by spraying into the air and looking at the pattern from the side. For me with the same tip you are using this is usually about 300psi. (30 on the gauge). Then increase the atomization air pressure until the horns disappear. Usually around 4-5 psi when spraying, maybe 7 but I've never turned my air over 10.
You don't say what the temp was but maybe you need to add 2-3% retarder so the solvent can flash off before the finish skins over.

[Nick Sorenson]

To answer all of the questions above, here's what we did: took the nozzle off, put the stinger in a 5 of thinner and primed the lines just to make sure everything was good and clean. Then we cycled the thinner out of the lines and primed in a new Gallon of Lacquer. From there when we could see a steady stream we put the aircap and nozzle on and dialed the pressure on the fluid to various ranges (10 - 60 on fluid) and balanced with minimal air to atomize the fan (stopped just at the even atomization point and even experimented with more air just to see...). Then we sprayed a few test pieces. I had a maple board with no colorants, a black painted piece of maple scrap, and finally a piece of cardboard.

The gun was a brand new Xcite. The pump was a 10-14. It had functionality issues right away. It would just hiss and not pump like the air wasn't able to keep it cycling. Finally I oiled the pump area near the spring and made sure it was plenty on the fluid pressure and no more issues with that.

But I see lots of tiny bubbles immediately. The reason I'm calling it solvent pop is that I notice it with too heavy a coat with ANY gun I've ever used (conventional and HVLP). I currently thin my clear 50/50 (at minimum) with an Iwata HVLP. If I don't I either have a very rough finish (micro drywall texture finish) or I have tiny bubbles if I spray wet enough to flow it out.

The same applies to what we were getting with the 09-114 tip and the Kremlin. LOTS of bubbles in the finish. I could spray a very fast dry to medium pass and have a rough looking finish that doesn't flow or I could spray a wet flow coat with bubbles. There really wasn't anything in between. This is with 100% lacquer right out of the can. Everything that had any sort of build to it had bubbles. Dusting it on didn't have bubbles but I wouldn't call that coating anything.

Temperatures were 70F approx in my booth and low humidity. This was not a blushing issue. It was with 100% certainty lots of tiny air bubbles. So many that it obstruct the appearance of the wood or color below. I've never seen anything like this.

But on the same token I'm sure I could do the same with any gun if I layed it on thick enough. But thick wasn't the problem. I'd spray a coating about 2 wet mils and it'd be bubbly as could be. No matter what the thickness I'm getting bubbles.

[Jay Brewer]

I would definitely try a different lacquer. I have been using ML Campbell Magna Max for a while now, and I am getting a great finish right off the gun. I am using the same tip you used, with the Fluid at 30psi and the air at 12 psi. no thinning of the product. I think the unit you tried was defective or your lacquer was bad.

The fact is, they are one of the best spray systems in the world, thousands of businesses depend on Kremlin to deliver the results that you are expecting.

Dont give up yet, it was one of the best investments I made.

[Nick Sorenson]

......I think the unit you tried was defective....

This is what I'm wondering. Something weird is happening here because no matter what we do we have air bubbles. It's a demo model and I have no idea how clean the internals are or how well it's been taken care of.

By the way we tried two different brands of brand new lacquer. One was the common SW Pro Mar which is designed for Airless.

[michael gates]

I would say it was sucking air from some where, someone may not have assemble it properly or missing an o ring, loose connection etc. When there is air in the line it looks like milk trapped under a layer of lacquer.

I spray a lot of black finishes as well and it is great to really let you see what is going on with the lacquer. When you spray clear over black it does appear milky but clears up with in seconds.

What is the Kremlin rep doing, are they bringing you back another one to try?

Are you sure they where actual bubbles, not pinholes? what happened when the product dried? Did you try a heavy coat, like 4 mils?

[Steve Jenkins]

since it is a demo model one thing I'd check is to take off the air cap and look inside it at the bottom of the fluid tip. There should be a small white teflon washer that forms a seal between the fluid tip and the orifice in the gun when the air cap is screwed on. Those wear out over time. if it is missing put one in if it's there replace it.I sure would not base my decision to not buy a Kremlin on that particular unit. They are really great rigs. I also spray a lot of high gloss, both clear and black.

[Nick Sorenson]

Thank you Steve and Michael, I will check to see if there is a leak somewhere. I hate to disassemble the reps demo model (thats his territory) but I don't think the rep has the mechanical ins and outs on this unit.

At this point I think the best bet would be to bring another unit. If it were mine, it'd be torn down right now for inspection. We'll see what happens.

[Nick Sorenson]

Ok I must have had a faulty unit. I've got a feeling that there's a leaky check valve in the fluid pump (bottom half) of the Kremlin.

I don't know exactly what the problem is but I can tell that it's pumping air into the mix. Everything that comes out is a foam.

ALSO: tonight I tested a Graco Airless (This model)
http://www.lowes.com/ProductDisplay?...llow&cId=PDIO1

And I was surprised at the quality of spray. It really did a nice job. The quantity of fluid required maybe 1 pass for the entire guitar. But it did a great job. I was pretty amazed at how smooth it flowed out and no bubbles.

But it was way too much volume for what I'm doing. It's like trying to drink from a fire hydrant. If I could get that type of atomization out of the can (no thinning) and a bit more control, I'd be in spray finishing heaven! Really the airless (without AA) seemed to work pretty well other than the size of the fan and amount of fluid.

So far I'm pretty disappointed in the Kremlin however. We'll see if they decide show me a product that works. It's not their fault that this one has problems and it's good service to come to a location. But service that is doing them and the product no justice if they can't rectify the problem. I know for certain I wouldn't buy one based on what I've seen thus far. I will wait and see what they say.

[Jay Brewer]

Hi Nick, I have a larger Graco Airless I use to spray paint. Which is really what it is intended for. You can get a small enough tip and use it for laquer but it puts out so much material you have to move very fast and I bet 1/2 the material gets wasted in overspray. These usually operate around 1500 to 2000 psi, which is the reason you got a good finish out of it, kind of like turning the pressure up to 80 psi on a regular cup gun, you get a good finish, but you wasted a lot of material doing it.

The huge selling point of AAA is transfer efficiency. You don't get all the over spray like with other systems. This in turn saves money ( lacquer isn't getting any cheaper ).

Your dealer should give you a NEW unit to demo, the one you have is obviously defective. My dealer gave me a new unit, and told me he would come in 2 weeks to pick up the unit or a check. They know more times than not, they are coming to get a check, and I gladly wrote it.

Lean on your dealer a little harder, I cant believe they are not working harder to get you a working unit.

[Nick Sorenson]

Well the rep came back. He was very helpful in bringing another tip. He is located an hour away and was making rounds today.

However even with the smaller tip size (a 06-093), it's spraying better for my size work piece but still with bubbles. The strange thing is that it's either orange peeled (too dry to flow) or it's wet enough to flow but with bubbles, the in between ground or sweet spot was so narrow of a margin that it'd be impractical to use in production.

I'm guessing I'd have to thin/retard it to get flow without the bubbles. But that's what I'm doing now with my Iwata so I'm not really gaining any ground.

The goal was to spray straight out of the can.

Without too much rambling one last detail, the rep said that the pump isn't pulling air because it'd be struggling to pump if it was. The pumping seems to be working just fine. It builds pressure quickly and stops. Also it's a steady flow of fluid (no sputtering or spitting). I think he might be right.

I'd like to compare it just to see if this unit was bad. I'm thinking it was ok. I do know that Sherwin HiBild didn't spray right out of the can with any sort of useable results. This was a little bit of a let down after having the Kremlin built up in my mind. But on the other hand it's good that it wasn't more effective because I would have had to generate some major sales to pay for it! lol. I had the Kremlin 10-14 and the Xcite gun for the demo. Maybe the model of the gun was at fault.

[michael gates]

I have had an Excite ever since they came out. They are nice. I also have an MVX which is nice as well.

If you are spraying guitars and don't have experience with a Kremlin an 04 tip would probably be good. I use an 09 most of the time for spraying furniture. I have an 04 and 06 but they are way to slow for me.

It is clear to me that your rep has no idea what he is talking about. I cant believe that they would send someone out to sell you a unit that cant troubleshoot, especially the second go around. What a shame you are missing out on a fantastic system. My Kremlin is the best tool I have bought, it turned my work from backyard to professional.