Advice on HVLP

[Yves]

Hi,

Thanks all for the advices,

Can you give me advice on the proportion normally used to "thin" oil paint or lacquer, or is it just try an error?

"Bernie Hunt" a écrit dans le message de news:sYHLc.271$ [e-mail]...

[Bernie Hunt]

Your gun will most likely come with a viscosity cup. Its a cup with a hole in the bottom. You fill the cup with coating and time how long it takes to drain. For example, I know that tap water takes 15 seconds. Your gun with then say what needle and nossle to use for each viscosity rating.

I talked to Benjamin Moore, who makes the enamel I used, and they said I could think up to 10 or 15%. I forget which. I actually thinned about 25%. The viscosity was still quite thick, but I used a large nossel and needle and it worked. You gun will probably come with some guidelines about how much you can thin different types of materials. Also the manufacturors will usually give you some guildelines also. I sprayed some anti graffiti paint that was really nasty stuff. The manufacturor even published which nossle size to use with HVLP. (BTW, the paint came out great and it really works, you can clean off graffiti with paint thinner and the original paint still looks great!)

Worse case, if you have all the different sized tips, then if it isn't spraying like you want, then you change to tip up or down.

One thing I noticed is that the manufacturors tech sheets say don't thin. I call BM and asked about that, and they said its due to air quality guidelines regarding VOCs. For liablity reasons they say don't thin, but off the record, everybody thins.

Bernie

[George E. Cawthon]

I have a conversion gun, which I am sure is slower than your Apollo, and painted the ceilings of five rooms and a hall (all with popcorn ceilings). My gun was quite a bit slower than a regular gun but of course the overspray (really the floating aerosol of paint) was practically zero compared to the regular gun.

So the answer is, no you didn't make a terrible mistake, but it may take you 2-3 times as long as using a regular gun. You will get better coverage, may get a better surface, and will certainly have less overspray.