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Spraying With an Air Brush
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Author:  Pat Hawley [ Sat Jun 06, 2009 5:41 pm ]
Post subject:  Spraying With an Air Brush
So I bought this one gallon DeWalt compressor and nailer package to do hardwood flooring at my daughter's house and it's working great. However, at .75 scfm, I don't know if the compressor is good for much else. Then I looked up airbrushes and it looks like that could fit the bill nicely. So I'm wondering if it would be possible or make sense to try and apply a finish to a guitar with an airbrush. From what I've seen on the internet it look like you can get airbrushes that will do a 2 inch wide sweep which strikes me as not too bad for a guitar. Does anyone have any experience using an airbrush to apply guitar finish? Did it work OK?

Thanks in advance,
Pat
Author:  the Padma [ Sat Jun 06, 2009 10:44 pm ]
Post subject:  Re: Spraying With an Air Brush
Yes an air brush will do the job.

Definitely stay away from double action air brushes. They just will not cut it.

The best air brush for this purpose is the Passche H model with a # 5 tip and the Passche 3 oz bottle meant for the H model. Get an extra bottle.

The Passche H is very reasonably priced and one heck of a sturdy workhorse. No other airbrush can cut it for this type of work and I have been airbrushing for 40 years.

http://www.paascheairbrush.com/

You will need a decent water trap and oil trap in the feed line. They are an absolute must. Don't buy the ones from Paasche...they don't cut it.

I also recommend purchasing the longer 15 or 20 ft hose....makes it easier to work with.

Yes there are other single action airbrushes on the market....don't waist your money.

Strain your liquid through a silk or nylon stalking.

Strain your liquid through a silk or nylon stalking.

In case I forgot to mention it...Strain your liquid through a silk or nylon stalking.

A few things. DO NOT rely on passing water or thinners through the gun to clean it. Take it apart and wash the tip, needle and needle cone immediately after spraying. Especially if you are squirting lacquer. But you will learn this the first time you don't do it. You will need a few pipe cleaners, Q tips and some fine wire...I use the wire in the twists for garbage bags or the twists from the produce departments. Remove half of the paper or plastic covering from the twist to expose the wire...leave the other half on the wire as this will act as the "scraper" to get inside the fine tube and the cone for cleaning.

Do NOT disassemble the mechanizem inside the air flow. It will only cause you hours of grief trying to get it back together. In 40 years...I have had only one gun that had a problem in this area and it was on a brush that had been pushed daily for 7 years spraying acrylics. Yes, the Paache H is truly a work horse. I have 4 of them, one of which is 40 years old, never been taken apart other than to clean the tips and its still going strong even after being dropped on concrete countless times.

The secret to a good spray is VISCOSITY and AIR PRESSURE...... and no I can't describe it to you because of the variable of temperature and humidity. Its just something you gonna have to fiddle with. Sometimes all it takes is + or - a pound or two of pressure or an extra drop or two of thinner,
and all of a sudden ...wam! The gun is spraying like a charm even though it is the same liquid you sprayed yesterday...and thats because of humidity and temperature.

Don't let that last paragraph scare you .... the Paasche H is probably the most forgiving and easiest to use airbrush on the market.

With all that said...and although I have finished many an instrument with the Paasche, I would still suggest a HVLP setup. Now if your into sunbursts, or using mica based particle paints such as iridescent or interference colours, then there is no other choice...get the Paasche.

Good luck.


Blessings
the
Padma
Author:  Tai Fu [ Sun Jun 07, 2009 3:54 am ]
Post subject:  Re: Spraying With an Air Brush
I think I would get a compressor that's a little bigger like a 5 gallon, 1.5hp (around 4 cfm) and use a mini HVLP touch up gun, or a normal full sized (non HVLP) spray gun for clear coats. To put things into perspective I spray about 4oz of liquid per coat onto one guitar body, and this is with a normal gun with a 1.5mm tip. So while a paasche H will cut it you will need to thin the liquid more due to the smaller nozzle size, which means you will have to spray more coats to get the same amount of solids (probably 3 refills for one coat) and you run more risk of runs because you have to thin the lacquer so much. Also you won't be able to spray things like sanding sealer or primer because they have larger particle size, a #5 tip won't atomize them properly. Airbrushes (like paasche H) are good for color coats that require fine pattern or atomization, for sunbursts for example, or fine illustration. I personally used a mini spray gun for sunburst because I can get better control as well as more fluid capacity. Double action airbrush should only be used for illustration (custom airbrush graphics or flames).

Also I had compressor like yours I got rid of it pretty quickly because it was very noisy, because it's one of those oil-less designs that uses a bladder rather than a piston. I got a piston compressor that's got a 5 gallon tank and 4cfm, for around $100 dollars, you should be able to find something similar from Grizzly or Harbor Freight. These compressors are still noisy but they are a lot less noisy (I'd say by 10db which is alot!) compared to those oil-less diaphragm designs and will last longer. The only downside is they require oil, and you will have to get a water/oil filter (required for any spraying) but they are far more efficient for the amount of noise produced. I think the best as far as noise/cfm is belt driven but they cost more.
Author:  Pat Hawley [ Sun Jun 07, 2009 6:30 am ]
Post subject:  Re: Spraying With an Air Brush
Thanks for the responses. I'll probably give it a try since I've got the compressor and the Padma has me sold on the Passche H. I don't want to turn this into an advertisement for DeWalt, but it really is a great little unit and one of it's main attributes is that it's quiet. I have heard other small compressors Tai so I know what you mean about them being noisy.

Pat
Author:  Aaron O [ Sun Jun 07, 2009 3:58 pm ]
Post subject:  Re: Spraying With an Air Brush
Sorry for the newbie question, but why would a double action A/B not be recommended in this situation?

From an airbrush standpoint, I find the double action gives you more control coming into the start point because you can keep the air going like a full or jamb gun.

Note: I've done an `ukulele with a Paasche VL and #5 tip, and I'd never do that again. Of course, if you already have the A/B and the compressor, there's no $$ invested, and would be worth a try, once to see. Just MHO.

Aaron
Author:  the Padma [ Sun Jun 07, 2009 4:27 pm ]
Post subject:  Re: Spraying With an Air Brush
Yo, Pat...you asked if an airbrush would work...The reply is still yes. However...I still would recomend a HVLP system.


Aaron , yes a double action gives you more control coming into the start point However the learning curve on a double action is an anus horribilus nightmare compared to single action...which can be preset for flow of both air and liquid, gives a larger spray area and is
consistent for large work. Furthermor the H single action is designed to handle thicker liquids....yes even primers and sealers...I have sprayed them many times although them must be thinned and pushed with more air pressure...like 50 or 60 lbs.....just don't leave that amount of pressure in the hose for too long.

But Pat, although an airbrush will do the job...you will truly be better off with HVLP for all your top coats and use the H for bursts and other effects.



Blessings
the
Padma
Author:  Mike_P [ Sun Jun 07, 2009 4:36 pm ]
Post subject:  Re: Spraying With an Air Brush
there is one concept I see that hasn't entered the conversation so far...

proper spraying technique is to overlap the fan pattern by 50% as you spray back and forth...

for example (we'll talk about a rectangular piece of wood here to simplify the concept), I'll start spraying by having my nozzle right on the edge of a piece of wood...then the second pass will be so that the nozzle is going right over the edge of the pattern from the first pass...

with the fan pattern you describe you are going to have to make an awful lot of passes to get the project covered...also you will most likely be having some dry line issues...and I think the dry line issues will be accentuated by the fact that AFAIC the bottle for the airbrush won't contain nearly enough material to spray a whole guitar....i.e. you will have to stop and refill the thing repeatedly....

I agree, its possible with an airbrush, but I wouldn't suggest it...

since I've never tried using an airbrush for anything bigger than a small plastic model airplane (some 30+ years ago) I can't really comment beyond the above...

I guess if your budget prevents you from acquiring a starter level spray gun and a compressor with more power/storage its worth a try, but I'd definitely try it out on a piece of plywood first so that you get a good idea of what you will be dealing with...
Author:  the Padma [ Sun Jun 07, 2009 5:30 pm ]
Post subject:  Re: Spraying With an Air Brush
Yo, Pat

you got a compressor...go by one of them cheap spray guns form Sears...ya, they ain't the best....but it will do the job a lot easier and better than an H brush.

the
padma
Author:  Pat Hawley [ Sun Jun 07, 2009 5:44 pm ]
Post subject:  Re: Spraying With an Air Brush
Thanks again guys. I spent another day nailing down floor with the compressor and nailer. Worked fine but I don't think a one gallon .75 scfm compressor has enough wind for a spray gun. I'd be happy to be corrected on this. Anyway, the tool is doing what I got it for - if I found some application towards guitar building, that would just be a bonus.

Pat
Author:  Mike_P [ Sun Jun 07, 2009 6:28 pm ]
Post subject:  Re: Spraying With an Air Brush
Pat Hawley wrote:
I don't think a one gallon .75 scfm compressor has enough wind for a spray gun. I'd be happy to be corrected on this.

Pat


and that would be a correct assumption...my 2 HP, twin tank ancient Campbell Hausfeld wheel barrow w/8 gallons of storage and putting out just under 8 CFM barely works to use a Binks 2001 w/siphon or a Binks Mach1 SL with a pressure pot...it does work, and will keep up and arguably ahead of the demand, but barely....
Author:  MRS [ Sun Jun 07, 2009 9:37 pm ]
Post subject:  Re: Spraying With an Air Brush
An airbrush can work but in my opinion i think you could get better results with a spray can.
Author:  Aaron O [ Mon Jun 08, 2009 3:09 am ]
Post subject:  Re: Spraying With an Air Brush
the Padma wrote:
YAaron , yes a double action gives you more control coming into the start point However the learning curve on a double action is an anus horribilus nightmare compared to single action...which can be preset for flow of both air and liquid, gives a larger spray area and is
consistent for large work. Furthermor the H single action is designed to handle thicker liquids....yes even primers and sealers...I have sprayed them many times although them must be thinned and pushed with more air pressure...like 50 or 60 lbs.....just don't leave that amount of pressure in the hose for too long.


Ah, got it on the learning curve. Although the spraying concept is the same, the feel is different from A/B to gun.

Haven't shot an H, just opted to work through the learning curve because double action is where I'd be anyway.

Aaron
Author:  Fred Tellier [ Mon Jun 08, 2009 10:41 am ]
Post subject:  Re: Spraying With an Air Brush
I use a Paasche model H which is a leftover form my model airplane days, for touch-ups on repairs, but would not like to spend the time required to spray an entire guitar. To save some cash I guess one could put up with the inconvenience of a airbrush to cover large areas. I use a cheap hvlp touch-up gun with a compressor that is a little small for the job but manages to give me enough volume for a .8 gun tip but will not handle a larger tip.

Fred
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