Fine-Tuning Conversion Varnish Application Technique

Tip selection and formula adjustments can help prevent micro-bubble hazing and orange peel. March 29, 2006

I have a cabinet shop in Georgia and we do our own finishing. We have a couple of the Kremlin 20:25 pumps with the mvx guns and are using M.L. Campbell's resistant and Krystal. Unfortunately, I have had trouble spraying both products. If anybody uses the same Kremlin pump (20:25) and mvx gun and sprays M.L. Campbell's resistant and Krystal, and has very good results (slick as silk) consistently, I would really appreciate any help you can give me.

Forum Responses
(Finishing Forum)
From contributor A:
I demoed the 20:25 and shot Magnamax with great results. I bought the 10:14 and have had equally good results. I was having problems getting as much material out as the 20:25, so I jumped up a tip size. Preheating the material seems to help, too, in cold times. And yes, I shoot Krystal too, and it is a great product.

From contributor B:
Give us a heads up on what is going on here. It is probably solvent trapping, which is typical with Resistant. What are you using for tip 09-09? Are you thinning, and if so, what percentage? We usually use one size smaller tip 09 down to 06, and thin product at about 10%. Settings are usually around 40fluid and 12+air. Last time we sprayed it was few weeks ago. I don't like or even have to go that high with either fluid or air, but it worked with the resistant and was dead on.

From the original questioner:
I called and talked to Phil Stevenson, who owns and teaches at the AWFI, the morning after I posted my question about the problems I was having spraying Krystal. I was having trouble with orange peel and with little tiny microbubbles that wouldn't pop out before the finish dried.

I had put in the maximum amount of flow enhancer #2 that I could put in (20%). This actually brought my viscosity down to 17 seconds, which was too thin. It should be around 22-24 seconds. I have always been told that orange peel is caused by the finish being too thick or by improper atomization. Phil told me that orange peel can be caused by the finish being too thick or too thin. I also had my fluid pressure set too high and he said that was causing the tiny microbubbles. He said that too much fluid was hitting the product too fast. He told me to set my fluid pressure at about 25-30 (I have a 20 to 1 pump) and my air at about 20 (triggered). He also told me to run the fluid through my heater at about 90-95 degrees. I told him that I was using vinyl sealer under my topcoat and that when I sprayed the finish on, it looked like orange peel instantly. He said that happens sometimes with vinyl sealer. He told me to use Krystal sealer. He also said that I could put between 4 and 8 ounces per gallon of butyl cellusolve into the mix to slow the drying time. I set everything up just like he told me and it is spraying a lot better now. The only problem that I still have is that sometimes I still get some of the microbubbles that won't pop out. I had put 5 percent flow enhancer #2 in the mix but it didn't totally take the bubbles away. I am going to get some of the butyl cellusolve and see if it will keep the coating wet long enough for the bubbles to totally pop out.

From contributor D:
Regarding the bubbles, some call this microhazing and they may be eliminated with the new Ultra tips from Kremlin. They cost a little bit more than the standard tips, but totally eliminate the hazing issue. The tips end in "2" - like 09/092 or 06/092. Take the last number off your tip (check your invoice) and replace it with 2 and add 20 bucks.

From contributor E:
I have a contact number on these if anyone is interested, as most of your Kremlin distributor sales guys are not familiar with them. They're 84.50 plus shipping. Or I can give you the item line number, assuming it's the same all over. I'm not a sales guy or representative of Kremlin in any way.

From contributor B:
Another way to get rid of some solvent trap is to go up in air pressure, i.e., cause more bounce. It is a quick, easy way if the ultra-tips are not available.