Spray gun set up

[B. Howard]

Seems there are always lots of questions about spray finishing and sometimes it can seem like there is a fair amount of voodoo involved but in reality it is a fairly easy and straight forward process. One thing that never seems to get much mention is proper set up of the gun and proper technique in using it. So to help with that here is an article I wrote on the topic. Hope some of you find this helpful.

http://howardguitars.blogspot.com/20...-by-brian.html

[Aubade Acoustics]

Brian,
Thanks for taking the time to post your thoughts on gun set up. Thinking about getting into UV cured poly, any thoughts on it? Mike

[mirwa]

Love painting with uv,

In theory, you could start painting the guitar at noon and be packaging it up in its case ready for shipping that night, painted /sanded / buffed.

We like the uv gel so much we use that for all pore filling applications.

Raw wood, pore filled ready for painting in minutes.

Be warned the light is the dear part.

Steve

[B. Howard]

I do not use the UV but I do use a conventional peroxide cured polyester for my sealer and pore filler under all my finishes. It is 24 hours to sand and coat and that's quick enough for me without adding another piece of equipment. It is basically the same to spray though.

I run it through a similar gun with a 2.2 tip (if memory serves, need to actually go out and look). It is a gun designed for heavy body primer/surfacers. Same pressure and pattern. It kills the paint arrestors in the booth really quick. You really don't want to breathe this stuff when atomized

[tadol]

I rememeber taking a tour of the Larrivee shop in Vancouver, where they were using UV cured finishes routinely. They had a large turntable set up where they would spray one body, rotate it into the back part of the cabinet where the UV source was isolated, and as soon as they had sprayed the next body they could rotate the table and the previous one was completely cured. Very, very impressive - but until they figure out better ways to repair and touch up those UV finishes, I'm going to avoid them.

Thanks for the info! Last time I used a spray rig was in a shop where we could lay out flat and coat 24 doors at a time, shooting from a 5 gal pot. Not a model I'd pursue for my home shop, but it would be nice to have that much space -

[joe white]

Originally Posted by mirwa

We like the uv gel so much we use that for all pore filling applications.



Steve

Steve, how do you cure the uv pore filler that ends up deep in the pores where the light cannot reach? I have stripped many Taylor guitars that were uv pore filled only to find the filler still wet and not cured. The filler would leach back out into the wood after many wipes with acetone. I know builders that have had finish failures after the guitars have been completed and had to take the guitars apart, strip and refinish because the un-cured pore filler. I'm not being a critic of the uv pore fill but more of an information seeker since I have wanted to switch to uv pore fill but until I have been assured that it can be completely cured deep into the pore, I can't risk using it.

Brian, sorry to take your great gun thread in a different direction, maybe we could open this up in its own thread.

[B. Howard]

Quite allright Joe. I use the peroxide cure for that very reason among others. Do you know Pat Diburro? (hope I spelled that correct, sorry Pat) He does most of the repair work for Taylor and some other boutique makers and has been using UV for a long time. I have discussed his setup with him a fair bit. When he does it he does a double cure under the lights for each coat. He said and still recommends a 24 hour cure on the filler after that before topcaot as it is a bit easier to sand.

[mirwa]

Originally Posted by joe white

Steve, how do you cure the uv pore filler that ends up deep in the pores where the light cannot reach? I have stripped many Taylor guitars that were uv pore filled only to find the filler still wet and not cured. The filler would leach back out into the wood after many wipes with acetone. .

Good question, you are correct, you need to apply the first few applications as a rub rather than fill. It's a learning process like anything else. If it's too thick it won't cure fully.

I've been using uv now for about 4 yrs and we do respray Taylor's as required, prs now use uv and because of it's speed of drying it is a perfect medium for assembly lines.

I spoke with Taylor a while back re uncured gel, Taylor now uses uv cured gel and finish but it has a mix of something that allows any un cured sections to actually dry over time.

I haven't used the newest stuff yet, still on my other tins, but it does work great.

Steve