Official Luthiers Forum!

I've recently read Dan Erlewines Finishing book I have a small 7.5 cfm compressor with a 25l tank, and a standard cheap gun, I'd like to spray sunbursts... Now in the book he suggest a jamb/touch up gun I was loaned one and really couldn't make it perform satisfactorily, then I looked at the spray guns available from Stew Mac and compared them to the guns on ebay, and there is a huge difference in nozzle sizes.

The Stewmac Touch up gun has a 1.6mm medium flow nazzle where as most guns of a similar size have between a 0.8mm-1mm nozzle I've only found 1 gun that has a 1.4mm nozzle I think this is why I struggled with the gun I was loaned, now Stew Macs full size gun had a 1.8mm medium flow nozzle where as most full size guns I can find including mine have a 1.6mm nozzle, the only reason I hesitate using it is that if I was spraying a sunburst with it I'd need to mix so much stain to stop the gun spluttering as it's suction and needs to be a 1/3 full to operate ok.

Anyone else come across this?
All hints tips advice welcome

Thanks

John

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Formerly JJH

I learn more from my mistakes than my successes

There is too much to learn about a gun that can be posted in a few paragraphs . You want to get a good gun . I have 2 HVLP's . Get good one . Most guns will come with a few nozzles . Read the sprayers booklet and learn your equipment. Learn what the adjustments are and what they do . You can learn much from the net and look at the guns manufacture site. There will be some info there. I would read that before gleaning the web.
There is too much misinformation on the web so start the the manufacturers site and start from there. I have a Sata and Devilbiss . You can find a lower end gun but expect to pay about $100 or so. http://cgi.ebay.com/DeVILBISS-Blue-Fini ... 286.c0.m14 here is a link to a good gun .

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I've been spraying sunbursts on mandolins for many years, and I use a $200 Iwata airbrush. Never tried a spray gun, don't know if they spray fine enough...

If you can find one locally that will talk to you, talk to an automotive painter, or better yet someone who paints custom motorcycles. I've painted a few cars, but my Dad's neighbor does fancy paint jobs on custom motorcycles. He's helped me alot. Like John said, you need a good gun. Tip size is determined by viscosity of the material you're spraying and how big you want the pattern to be. With the proper tip size you'll have the trigger pulled all the way for the pattern you want. If you're only pulling the trigger a little bit the tip and nozzle will wear pre maturely and cause problems. Make sure the gun you get has different sized tips available. A Sharp Finex FX1000 is an excellent, but not terribly expensive ($110?) mini HVLP gravity fed gun. Tips from .06mm to 1.4mm are available and should do great for any finish you'd want to put on a guitar. I'd recommend starting with a 1.2 tip and going from there. Make sure your air is dry. You can use little disposible dryers that go right at the gun. I'd also recommend a good regulator. A few psi can be the difference between orange peel and sags. The better you do spraying the easier the buffing is.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

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Single action air brush for bursts and other effects.

Sears $!5. special for clear stuff. Well use to be that price way back when.

HVLP is best for spraying, I hear tell.


blessings
the
Padma

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Audiences and dispensations on Thursdays ~ by appointment only.


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One of the first issues you're probably going to have with getting a good gun, is getting a good compressor to back it up.

Just like quality instruments, guns are a good example of you get what you pay for. If I were doing sunbursts, I'd grab my son's Iwata (already stated). Its pretty sad when my son has an Iwata, and I'm stuck with my Paasche VL. Either way, both are dual action, just like the gun.
My Sata Minijet is for finishing. The airbrush compressor is good for the airbrush, but my 60gal oiled upright pushes air like its nobody's business (surely no problem for my impact gun). Overkill on the compressor? Maybe to some, but I've already gone through 3 oiless in the past 15 years or so, and those actually took up more room.

Back to the guns - the hardest part about my Sata is setting it up and getting everything right to match the material, from spray pattern, atomization, airflow and material flow. The best part about the Sata is that I can adjust all of that. Most other good guns will require the same attention. John probably said it best - do research, with the manufacturer first, then the net.

Aaron

There was a discusion a while ago where it was stated that a .9 and 1.0 was good for sunburst as they atomize better and give you a finer spray for blending the colors. But I agree with John about buying a good one. I too have a Sata and it works like you would expect a gun to work. It's a gravity feed. I think the Iwata was also mentioned .
Although the price of a $300 Sata or any other good gun seems high. It will save you material and should last at least 20 + years so if you break it down that's only $15 a year. One way to get past sticker shock. Check out your local dealer, maybe a place that the paint shops get their paint from. You will get better customer service form those places usually.

This is true only if you can't get a tip big enough.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

I'd like to see the flip side of that mando Haans. Looks great! What size tips do you guys use in the Iwata airbrushes for doing bursts? Also, what medium are you spraying with that tip. I'm guessing you would use a finer tip for spraying an alcohol based stain as opposed to a tinted lacquer?

Danny

air brushes are good for detail work but with some practice the jamb gun works fine. Remember the key to a great finish , isn't what you put on , it is what you let on. Between the level sanding and wet sanding and buffing and polishing Yup lots of work but for a great result.
No gun no matter how good will cover up bad prep . If you don't get the seal and filling down and learn the foundations of good finishing you can't expect the gun to do all the work. Lacquering is as much process as it is a finish .

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I think my Iwata has a .8 tip. Control is the big factor, and with an airbrush you have all the control you need. I don't know if you can get that much control with a gun. I use 2 Sata minijets for mandolins, one for oil and the other for spirit varnish. When I started building guitars again, I found them too small and went to a Campbell Hausfield $60 HVLP gun and it works just fine for lacquer. I use a water base for my Trans-tint, and wouldn't consider using tinted varnish.
Here's the front of that mandolin...

This there are a few guns on ebay I was looking at, out of the ones below which do people prefer?

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=250314072489&ssPageName=STRK:MEWAX:IT
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=250482743494&ssPageName=STRK:MEWAX:IT
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=320415587475&ssPageName=STRK:MEWAX:IT
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=380145557176&ssPageName=STRK:MEWAX:IT

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Formerly JJH

I learn more from my mistakes than my successes

Are you saying that you're spraying trans-tint in water directly onto un-sealed wood? I've tried that with disastrous results. The pic below is after trying to stain a very subtle amber burst directly on bass wood using trans tint in water. What you see is after I sanded away all of the surface "stain suck" which was even worse. This was my last screw up using dye in water directly on wood - there were a couple more disasters before that, luckily I didn't document them.

Since that time I've switched to spraying tinted lacquer over shellac so that at least if I screw up (see other pic), it's much easier to fix. Do you have any tricks you use to keep the absorption even? You're not the first I've seen with successful results using water dye on wood, I just can't figure out how you do it!

As to airbrushes - I'm thinking of picking one up for bursting as my jamb gun while atomizing very well has just too big a pattern for what I'd like to do. I liked the fact that with the stew-mac brush you can buy tons of little cans to hold the colors but if the gun is worthless, it's worthless. Any recommendations on the sub $50 airbrush market, hopefully something where you can keep colors in their bottles to easily switch?

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

John, I'm not familiar with any of those guns, but they look to be the usual fair from China (what isn't?). The last gun looks to be alright, but for me the tips are way to large for sunbursts. I've had a couple of variations on that first detail gun and threw them away.
I don't know if I need some bimbo with a tool belt to sell me a spray gun!

One thing to watch out for, what ever gun you buy is the cheaper guns will spit metal bits sometimes. It pays to tear the gun completely down, clean it out with solvent and check for flash. Watch it when you are spraying for a while and check every coat carefully for metalflakes.
Andy, nothing is worse than spruce for uneven staining. That said, most mandolin makers (I include myself) allow a little variance in staining (I should say dyeing) because of the carved tops. Loars were hand dyed and are the accepted standard. That said, some builders spray a coat of shellac onto the spruce before staining. I don't because it masks the grain a bit. I don't like dyed varnish or lacquer because they are extra coats, meaning that they cannot be sanded and leveled. So, you either sand and level the instrument before putting the colored finish on and then put the clear coats over that to final buff, or just put a lot of clear over the dyed base and level.
I used to have a $50. airbrush and threw it away. Most airbrushes have available extra bottles for keeping dyes and solvent in. I have about 6-7 for my Iwata. If you are doing sunbursts, there is nothing more important than a good airbrush or small gun, because mistakes are not easy to fix.
The top on the mandolin in the photo was a redo and took a lot of time to fix.

I did a lot of research when I bought my new gun (sata minijet). I wasn't satisfied by my cheap jamb guns. What helped me make my decision was Rick Turner saying he used the Sata minijets for his finishing and raving about them. The difference and ease of use for me is night and day from the cheap guns.

So is anyone bursting with an HVLP gun? I tried that on some test boards when doing the burst above and it was terrible. I have a mid-grade gun though - Astora something or other - and perhaps the high end HVLP guns can handle it.

The $15 jamb gun I think does a pretty good job at atomization, as shown by the pic upstairs. The biggest challenge is that even at low settings the spray pattern is pretty big. I think for guitar burst work it's probably good enough, but because of the shading effects I'm going for it's just too big. Any HP gun is going to leave a lot of finish or dye hanging in the atmosphere and to the O.P.'s original question, even the jamb gun needs a reasonable amount of finish to keep from sputtering. I use the HP gun to shade then put top coats on with the HVLP to save on finish and avoid the gas attack thing in the basement.

As to airbrushes - I definitely don't want to waste $30 on the stew mac one if it's junk. Any opinions as to what the cheapest decent airbrush is that can accept multiple finish containers?

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

I just found my Iwata Eclipse for $109 on the first look at google.

Sweet - do you recommend the bottom feed or gravity fed models?

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http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Andy, get the one with the bottle below.

I haven't used many guns, but my first ones were cheap touch-up guns. The results were predictable. A cheap gun just won't atomize as well as a higher-end unit.

I now have a Walcom Genesi Geo HVLP (1.3) and I love it! It was 280 on ebay. Superb fit and finish and it performs like a dream. Of course, like stated earlier, you have to learn how to use it, fiddle with the settings and whatnot, but I'd say go with a high quality tool. You'll never regret your decision.

Then it's just a question of learning to lay it on.

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I'd like to be able to prove, just for once, that money wouldn't make me happy...

How about a gravity feed gun (conventional) recommendation, please.
I would also appreciate at-gun dryer & regulator picks.

Thanks

Mike

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One thing to consider in all this is the material you're shooting - if you're shooting any kind of catalyzed finish, and forget to clean your gun quickly enough, then you're out one Minijet.

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The member formerly known as erikbojerik....

Tony, for the W-300, there are 3 applicable models, tips being the difference. WHich do you recommend?

Mike