Heat Problem with a Turbine Sprayer
Solvent-borne finish application problems are traced to the turbine air supply: heat generated in the turbine is making the finish flash off before it hits the wood. November 13, 2005
I decided to try one of these Turbinaire systems. It's the 1235 and I got it really cheap (relatively speaking) when I was in the sates about a year ago. I have done quite a bit of reading at WOODWEB, and it sounds like some people are getting great finishes with turbine systems.
I am trying to spray SW cab acrylic lacquer and I cannot get a decent finish. The finish has been thinned, different needles, fluid tip, and air caps tried, the air volume to the gun adjusted, fluid volume, etc.
At first I thought it was just orange peel, but I am starting to think that the fluid is not atomizing enough. Only other thing I can think of is to thin it more, and now I am really worried about blushing.
I have run the turbine at full blast and it has gotten better, but it is still not acceptable. I get better results with a cheap arse conventional gun and compressor. Anybody have tips, or should I just assume that this thing is going to be used for only latex paint? Can't wait to try that (shrug).
I'm not an expert on solvent borne finishes, but my guess is that the warm air of the turbine is making the solvent flash off before the lacquer hits the wood, so the lacquer is semi-dry before it makes it to the surface. This can be a problem with any turbine. You can try making the hose longer. This will allow the air to cool before it gets to the gun. A cheap way to do this is to use garden hose. If it works out, then you can get the more expensive air hose from the manufacturer.
Instead of using thinner, try some retarder. With the hot air from the turbine (as stated above), it may affect the finish before it gets to the substrate.
From the original questioner:
Thanks for the quick responses. Thought of this possibility, also. This unit does have the 5' heavy duty hose whip, but maybe the damn thing just doesn't work and it's still too hot.
Here in the Bahamas, I do not have access to retarders. Might be able to get a retarder for an automotive finish, but I really don't want to play with something I haven't done before. I have read a lot about adding MAK to the lacquer. Will this work and slow down the flash time to allow the lacquer to flow?
Add MAK. It is a good retarder and it will lower your viscosity as well, because it is also a strong solvent for lacquer.
I pull my turbine out when I am spraying oil-based stains or paint, or polyurethane. This is one of the drawbacks/advantages of this unit. The heat from the turbine causes the material to flash. Bad for lacquer, good for oil-base. I used a 15' hose and still have heated air at the gun. You might consider spraying with your other guns if you got good results. A retarder will thin the material. In essence, more coats for the same build.
From the original questioner:
Thanks for all the help, but I give up. I have now spent four or five days trying to dial this thing in, and I can't seem to get it. I have had up to 35' of hose on the unit and it is still not right. I have gotten it a lot better, but not anywhere near perfect. I am going to buy a brand new conventional gun just to spray this job. I have a 2qt. pressure pot that came with this unit, and I think I am going to look into buying a decent gun to use with the pressure pot. I can't see using the turbine with it because it will just be the same problem.
You bought the wrong type turbine. You should have bought an Accuspray - they have the best gun around. They don't heat up your finish.