Finish repair using an airbrush

[Luke Single]

I am an aspiring luthier and I am starting to get into finish repairs. I just bought stewmacs airbrush and I am looking for some guidence. I dont know anything about airbrushes. I dont know how to clean them or use them for that matter. I feel like I can figure it out, it dosent seem complicated but I am sure there are some do's and don'ts that I would rather not learn the hard way. I am going to buy an air compressor in the next couple days and the air brush should be here monday or tuseday. Thanks in adnvance for the help.

[William F.Eden]

 It's to bad you hadn't ask the question befor you bought the air brush and what ever.I had one and did not find enouf things I could use it for as far as repairing Insturments.But seeing you have already bought it and you want to keep it clean you just have to empty it when done using and put some Asatone in and spray a little though it and leave the Asatone in the container untill you need to use it again.  If you start to have trouble with it you take it apart and put all the parts in a container of Asatone to clean them.Bill...............

[Stefano]

Buy the book Guitar Finishing step by step of D. Erlewine. It's a very useful book. Another one is Understanding Wood Finishing. How To Select and Apply the Right Finish by B. Flexner.

[Michael P. Lemieux]

Hello,

I think it's very essential to have an airbrush. Good move. Instead of me writing a long reply, just go to YouTube and type in the question how to use an airbrush and how to clean an airbrush (that would be 2 separate questions). Believe me, you'll find all the information you could ever want on this subject. Just a thought.

Mike

[Luke Single]

Ok thanks guys I will try those suggestions.

[Ned Knepp]

 Hi Luke,

 I've used both a large spray guns and air brushes.  I only own an airbrush right now  and find that it is a very useful tool for the restorations/ repairs I do. I would like a larger system for total refinishes but don't have the money, space or even the real need for one at this time.

 One of the issues with painting/finishing system is the compressor. I use a small "pancake" compressor for my nail guns but I use a small rotary compressor made for use with the airbrush and find that it works better than trying to crank down the pressure on the other unit.  The airflow is consistent, the compressor is much more quiet and the whole system is very portable.

 Before you spend your money on a compressor, consider your total needs now and in the future. If you are going to use other air powered tools, sanders, sprayers.... you will need much more air than you will for an airbrush. If you are only going to spray finish/paint, you may want to consider a LPHV system which seem to work better with a turbine compressor dedicated to that task. The small pancake compressor I own is ok for driving my small nail gun or inflating tires once in a while but it's almost useless for anything else. It simply doesn't produce compressed air fast enough to use for spraying finish for very long and it will never drive a decent air sander. In other words, make sure you invest your money in something that will really do what you want it to do and will make your job easier instead of complicating it further. 

[Luke Single]

Thanks Ned that is very helpful. I have a medium size air compressor that is old but functional and will get me by while I decide what I should invest in. Ill have to look into the rotary compressor, I have never heard of it. I don't think I will be doing any major finish work at least not in the foreseeable future. So I think some thing small, simple, and accurate is what I need.
Can anyone tell me what pressure I am looking for when spraying? I have the stew Mac airbrush kit. It dosent come with any instructions or guide. I researched air brushes and the advice I received was follow the manufacture reccomdations. There are none! I contacted stew Mac customer support so we'll see if they have an answer. If not i guess that's what scrap would is for!
When spraying nitro or any finish for that matter should I be concerned that it could combust. I know it is flammable but is it realistic to think that a fan, or light could ignite the fumes while I am spraying?

[Kerry Krishna]

Luke, there are dozens of threads/treatise's on this on the Musical Instrument Makers Forum. Go and register, then go into their archives (which are pretty massive!) and have a 3 or 4 day look. It is all there, any question you can come up with concerning this subject. MIMF is a fairly odd place on the Web, vera old school, and has some truly odd/nasty moderators. Don't draw their attention, and you should be fine. It must be 100 times the size of this excellent Forum.  

[Luke Single]

Thanks Kerry I just signed up for it and I wil be searching around

[Donald A. Fortune]

Hi Luke-- Go to www.lmii.com and look at the rite side of the site and uou should be able to find all kinds of finishing tips along with many building tips-- good luck --

Peace- Donald 

[LARRY KLOSE]

Comments from the Gallery from a Nitro painter.

I've never sprayed instruments but I paint and finish fine scale models with Nitro. If spraying nitro, experiment with thinning and air pressure.  Properly thinned, I usually spray nitro at about 20-25 psi but it depends on the air brush and the lacquer viscosity.  Also, explore and experiment with retarder.  Lacquer thinner will flash off very quickly and may cause partial drying before the lacquer hits the surface with resulting orange peel.  Using retarder results in longer cure times but a very smooth finish.  This will reduce sanding and buffing to a minimum and facilitates thinner coats.

A slightly higher volume brush like a Binks Wren with B tip will allow spraying larger areas more efficiently.  The StewMac brush may be this type.  Many air brushes are designed for low volume, fine line work and don't do as well on larger surfaces.  The finer brushes may be very good for touch up and detail work, however.

With all of this, _lots_ of practice is imperative.  I've sprayed models for over 50 years and still have lots to learn.

Can't comment on water based finishes as I don't spray them--and the ones for models are lots different than those for instruments.

Larry

[Allan Lang]

Stew Mac sells a set of tapes explaining and showing"how too" on spray finishing