Switching Between Coating Types with Air Assisted Airless Equipment

Going from one product to another and back again is no big deal with AAA spraygun setups. March 29, 2008

We are a small two man shop and up to this point have been using two Binks 2.5 gallon pressure pots, one for paint and one for clear coat lacquers. Someone told me about the Kremlin air assisted setup and my paint distributor was pushing CA Technologies equivalent. Not sure which model. Anyone with experience of one or both? I want to upgrade, as it seems a better system than the pressure pots. Also, will I need two setups for paint and clear coat?

Forum Responses
(Finishing Forum)
From contributor E:
About the only thing you'll need for 2 setups is 2 hose sets and perhaps 2 or 3 extra tips for different material on a Kremlin. Going from a pot pressure system to a Krem is like trading in a tricycle for a car.

From contributor T:
Contributor E is right. I had two Binks Mach 1's on pots and switched to a Kremlin several months ago. I am sold on the Kremlin and wouldn't think of going back. You won't regret the upgrade. Can't tell you about the CA Technologies product.

From contributor R:
Be sure and get a 3 way manifold and their 1 gallon gravity feed funnel so you can empty the dregs of a 5 gallon into it or spray as little as a pint or two!

From contributor W:
The CA Technologies pump will work fine. It is very similar to the Kremlin and should be a little cheaper to buy and maintain. I have two friends that run them and love them. They also sell parts for other spray equipment that I buy from them for my Binks and Devilbiss guns at a cheaper rate.

As far as getting 2 setups, I would say yes, because the oil and solvent don't mix. You will be constantly contaminating the system. If you are short on money I would recommend that you buy 1 pump now for the system you use the most and keep using the pot for the other until you can afford the second pump.

I would say switching to the AAA system is usually the best thing for a lot of shops if they use over 20 - 25 gallons a week. If your average job is 3 - 4 gallons or less I would say stick with the pot unless you just have extra money to spend.

Just a side note... Depending on the gun you have on the pot, you may actually see slight loss in quality. The AAA guns are rated at decorative class B, unlike a conventional class A gun typically used on a pressure pot. If the guns you use now are HVLP, then you would be about the same.

From contributor W:
One more thing - if you do purchase a pump for your paint line (latex/oil), make sure you don't buy the standard 14:1 ratio pump, as it will have to work very hard and have a shorter service life. Look into getting one with at least a 20:1 ratio or better with around 30:1 being optimal for high viscosity material.

From contributor E:
Good point - Kremlin has a newer heat device that would also help with the heavy materials. To a degree, you can balance viscosity with the tips and pressure, but the larger pumps are the best way to deal with those materials if you must use them.

From contributor P:
When I read the first post I thought the question was about lacquer - pigmented lacquer (paint) and clear lacquer. I didn't get any idea that latex or oil-base finishes were involved.

If you use pigmented lacquers, conversion varnishes, and/or 2K polys, you can run some thinner through the pump to flush out the pigmented finish and switch over to clear finish in just a few minutes. You don't need two pumps for the two finishes. If you have two guys spraying at the same time, then two pumps come in handy.

From contributor Y:
I agree with contributor P. I switch materials sometimes several times in a day. Even WB to lacquer and back again. The lines are relatively easy to flush, maybe 5 minutes beginning to end. Have never used the manifold but I would imagine if they are running off the same intake tube or pump, there would be some flushing of the system before it reaches the fluid line. Anyway, bottom line is that the switch between coatings is not a difficult or timely process.

From the original questioner:
Just to clarify, I can use one pump and the same lines to shoot clear coat and paint (both ML Campbell lacquers, Magnamax and Resistant) without getting contamination in the pump of the Kremlin? Is anyone doing this successfully now?

From contributor P:
That's exactly correct. Contributor Y pointed out that he's doing it as much as several times a day, and I do it frequently. I have never had any problem with paint residue getting into clear coats or other paint colors. Just clean the fine filter in the handle of the spray gun on a regular basis to keep it from clogging.

I have left pre-cat lacquer, primer and paint in the pump for as many days as it took to finish a job and then switched over to another finish (clear or pigmented) after running solvent through the pump without any problems ever. I keep a 5 gallon bucket half full of solvent near the pump for this purpose. The first 5 strokes of the pump (more or less) I will spray into a dump bucket and then recycle the solvent into the bucket it came from for 30 seconds or so. The finish in the lines goes into the dump bucket and then running the solvent through the pump for 30 seconds makes sure the lines are clean.

When I cycle solvent through the pump, first I'll spray through the tip to clean it out, then remove the air cap, turn the atomization air off, and lower the fluid pressure. Without the air cap and tip in place, the solvent goes through the pump very fast (that's why I lower the fluid pressure).

From contributor E:
Yes, you can, but swapping a hose set is very quick, so why think in terms of just 1? I leave a little thinner in the hose even when it's off the pump. You'll have to try one to understand, I suppose, but moving between material types is fast once you get used to the system.

From contributor O:
I change between MLC Resistant and Krystal all the time. I just recently invested in a CAT bobcat. Switched from turbine with pot. I flush my line and leave thinner in it. As I see it, the problem with using two separate hose sets is you need to keep thinner in the set you are not using so it won't dry out and get crusty. If the set is not sealed to the pump and gun, the solvent will evaporate, leaving a film that will eventually build up and fall into your finish at the most inopportune time. I have no problem with using the same hose set. I have been using one hose for my pot setup for several years with very little problems.

As for the CAT setup, I am still learning, but I am already producing better finishes in just a couple of jobs. I feel it will get much better, both consistency and quality, with more experience.

From the original questioner:
Thanks everyone for the responses. I came upon a document from EPA on the Kremlin pump. Confirms what you all say. A rep will demo the Kremlin setup on Friday at our shop.