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Bernie Weishapl
08-21-2005, 9:17 AM
Was wondering what nozzle size one needed to spray mainly lacquer with a HVLP? I see them listed at .8 mm to 2.2 mm. I have seen claims that some of the sprayers will spray lacquer, enamel, stain, primer, urethanes and clearcoats. I know from reading posts here that paints are not good sprayed with these guns and that urethanes not be sprayed either. Can you spray shellac with them? I am really new to spraying as I have just used the spray cans in the past. This get to be pain and costly. I have been doing some research on spray finishing. Any info on books or articles on the net would be appreciated.

Bernie

John Renzetti
08-21-2005, 9:55 AM
Bernie, Best to check with the manufactuer of the unit. Recommended nozzle sizes for type of product to be sprayed can vary with the model of the gun from the same manufacturer.
take care,
John

Kirk (KC) Constable
08-21-2005, 10:46 AM
I've sprayed lacquer with both a 1.3 and a 1.5 in an Asturo gun...didn't see much difference. I've also sprayed lacquer with whatever comes with the two Harbor Freight guns with the remote pot (I have both). I suspect they're much bigger than 1.5, but with a bit of practice and careful setup, they do just fine.

KC

JayStPeter
08-21-2005, 11:52 AM
Not an expert, but just got an HVLP setup. It varies depending on the type of gun (i.e. gravity, pressure, etc) and most likely by brand a little also. I also think it is different for touch up size guns. Here's (http://www.homesteadfinishing.com/pdf/generic_viscosity.pdf) a generic chart to show starting points.

Jay

Phil Phelps
08-21-2005, 2:03 PM
Bernie, a HVLP is a siphon gun that applies more material than a conventional siphon gun with about 80% less overspray. They need a lot more air to operate, if you are using a conversion HVLP. You can, of course, buy the turbine HVLP and have no need for a compressor. For the conversion HVLP, you'll set your regulator at about 75 to 80 psi. It would be best to have a regulator between the end of your gun and the hose. You can spray about anything you want with the HVLP, and that includes latex paint and urethanes. Your tip size will vary, but there should be a chart with the gun you purchase. The important thing you should remember is that you will reduce nearly all material to flow through the nozzle of your gun. That's why I don't recommend latex paints. You have to thin them so much that it brakes down the material and reduces the sheen. Oil paints will lose their sheen the more you thin them. And, it's very hard to cover vertical parts with thin oil paint. It will take at least two, three, maybe four coats. I spray lacquer, urethanes, oil, shellac, and some paints that most folks have never heard of. Proper thinning, tip size, air pressure, temperature, and flow, all play a role in the success of your finish. And not to forget, preperation is eighty percent the work.

Jim Becker
08-21-2005, 3:20 PM
Phil, the gun doesn't have to be siphon type...plenty of the HVLP guns are gravity feed. (Not my preference, but nice for certain circumstances)

Phil Phelps
08-21-2005, 4:42 PM
Phil, the gun doesn't have to be siphon type...plenty of the HVLP guns are gravity feed. (Not my preference, but nice for certain circumstances)
I forgot all about them. They are useless in my business.

Bernie Weishapl
08-21-2005, 6:35 PM
Thanks a bunch guys. It will give me something to think about. I was going to get one of the gravity fed ones with the smaller 600 cc cups as I will not be spraying anything real big but hate having to buy a bunch 8 cans to do the job.

Anyway it is much appreciated.

Bernie

Michael Gabbay
08-21-2005, 9:37 PM
Bernie -

Normally lacquer would be sprayed with anything from a 1.5mm to a 1.9mm tip. The best thing to do is get a viscosity cup (Ford #4 for example) and test the viscosity and go from there. I have sprayed Oxford USL with both a 1.5 and 1.9 tip. When it is thin I use a smaller tip. When it is colored lacquer I use a larger tip but it still depends on the viscosity. Also, you can thin the material if you don't have a larger tip. Also, I have an HVLP gravity gun (Asturo BBS).

Talk with Jeff Jewitt and Homestead Finishing. He's a great help for the specific setups.

Mike

Bernie Weishapl
08-21-2005, 11:12 PM
Thanks Michael I will give him a call. I can see I still have a lot to learn about spraying but I think it will still be better than buying cans of lacquer and trying to do the job. I was real disappoint in the rocking horse I did for my grandson. I always seem to come up a partial can short and lots of overspray. Anyway I will keep researching and reading. Thanks again one and all.

Bernie