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Spray equipment and set up
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=38326		 Page 1 of 2
Author:  Heath Blair [ Wed Nov 21, 2012 6:13 pm ]
Post subject:  Spray equipment and set up
So on the heels of my brain being broken by my finishing abilities...

I want to try my hand at finishing with a spray gun. I have a 20 gallon 5 HP Campbell Hausfeld compressor rated at 8.1 SCFM @ 40 PSI. What else do I need? And what specifically do you recommend? I'd like to get everything for a couple hundred bucks or so. Is that realistic?
Author:  Rod True [ Wed Nov 21, 2012 8:18 pm ]
Post subject:  Spray equipment and set up
I Have a smaller compressor than that. I use a Campbell Hausfield touch up gun for spraying. Cost is around $40.
Make sure and get a moisture trap between the compressor and gun.

Image
Author:  Chris Pile [ Wed Nov 21, 2012 9:22 pm ]
Post subject:  Re: Spray equipment and set up
Get a gun with a teflon coating inside.
Clean up is a breeze - swish a little thinner around in it, and you're done.

I have a Sharpe touch-up gun. 2 cups. I've never used but one in 30 years.
Author:  SteveSmith [ Thu Nov 22, 2012 8:51 am ]
Post subject:  Re: Spray equipment and set up
I've had good luck with a $30 jamb gun (edit: it's a CH brand from Taiwan so I suspect Campbell Hausfield) I got at Walmart or somewhere like that. It has it's quirks but got the job done for the last 6 years. It won't take long to figure out what you like and don't like.

I haven't had a chance to test it yet but just spent about $200 to upgrade to a Walcom ECO gravity feed gun that's made in Italy. It's an HVLP gun that runs off of a standard compressor.

The Fuji's are nice and maybe I'll get one someday but they are a higher cost.
Author:  klooker [ Thu Nov 22, 2012 8:55 am ]
Post subject:  Re: Spray equipment and set up
I'm a hack at finishing but slowly getting a little better. I have a Fuji turbine setup but my biggest problem was lighting, you need to see how much finish is going down so that it flows out but doesn't run.

Kevin Looker
Author:  John Coloccia [ Thu Nov 22, 2012 9:51 am ]
Post subject:  Re: Spray equipment and set up
I would budget $50 to $100 for Dekups or 3M PPS. Once you do the disposable cup system, you'll never go back to anything else. Personally, I use the QS-600WB that Homestead sells. I don't think $200 is enough for a complete setup, but about $300 will get you a pretty high quality gun, some cleaning supplies and a disposable cup system.
Author:  SteveSmith [ Thu Nov 22, 2012 10:19 am ]
Post subject:  Re: Spray equipment and set up
John Coloccia wrote:
I would budget $50 to $100 for Dekups or 3M PPS. Once you do the disposable cup system, you'll never go back to anything else. Personally, I use the QS-600WB that Homestead sells. I don't think $200 is enough for a complete setup, but about $300 will get you a pretty high quality gun, some cleaning supplies and a disposable cup system.


You're right, the cleaning kit and a PPS system will bump mine up to $300 easy. I couldn't find a Dekups adapter for my Walcom EGO but PPS has one.

Sorry for the partial hijack, but anyone have a recommended online supplier for the PPS system components?
Author:  Fred Tellier [ Thu Nov 22, 2012 10:29 am ]
Post subject:  Re: Spray equipment and set up
I used the cheap Chinese HVLP guns for a few guitars but the needle seals would start to leak after a couple guitars causing the spray pattern to flutter. I decided I could not afford the several hundred dollar guns but my criteria was at least available parts to rebuild it. I decided on the Devilbiss StartingLine Mini Detail & Touch-Up HVLP Spray Gun which can be had for less than $80.00. It sprays a great pattern and after using it on 10+ guitars still functions real well. I purchased a rebuild kit for it but it probably will never be needed with the amount of spray time required to finish guitars. I recommend getting a good quality inline air filter/dryer and use it right at the gun, I throw these away after a couple guitars though the running time is less than recommended by Devilbiss and have never had any contamination problems in my finishes.

Fred
Author:  weslewis [ Thu Nov 22, 2012 10:38 am ]
Post subject:  Re: Spray equipment and set up
I have been thru a few of the harbor freight guns, like Todd said some are pretty bad they leak and are hard to get a decent pattern, but the one I found that works really well for spraying EM 6000 is the 92126 detail gun, not sure if it would work with varnish due to its small nozzle, but works amazingly well for the water based lacquer..has a stainless steel cup , doesn't waste too much paint when spraying due to its size,easy to clean , low parts count , and lays down coats with almost no orange peel...I was pleasantly surprised , I paid about $30 for mine but now they are always on sale for around $15..
Author:  B. Howard [ Thu Nov 22, 2012 11:12 am ]
Post subject:  Re: Spray equipment and set up
John Coloccia wrote:
I would budget $50 to $100 for Dekups or 3M PPS. Once you do the disposable cup system, you'll never go back to anything else.


I have used harbor freight guns for quite a few years with good results, and when you consider they are disposable at that price, I would simply toss them when they got too dirty and acted up. I use an Apollo turbine for cabinets and furniture, very nice system. My apprentice has a Fuji, again very nice but they are loud and I have air to spare here. And since I am increasing my finishing work here at the guitar shop I have recently bought myself a nice Devilbiss SRI pro. Beautiful gun for this type of work. And it has the Dekup syatem, which is really great. This was in part a decision based on the fact that I wanted to be 100% environmentally compliant here, so far my neighbors like me. Clean up is a snap with virtually no solvents and the partially full dekup can be easily stored and re-used and even re-filled.

In regards to Heath's original post. Your compressor head seems like it may keep up but the lack of air capacity may pose some issues. Your compressor will probably run a bit more often which will lead to an increase in moisture and oil contamination in your air supply. Get a really good filter and separator. Don't go cheap on your hose, larger hoses work better, it's about air flow not so much pressure. I would recommend Buying an HVLP gun with the best transfer efficiency you can afford, The savings in material and solvents are good enough reasons but less exposure to chemicals is really good. While on that subject don't forget safety equipment. A good respirator is mandatory no matter the type of finish. Most people incorrectly assume that waterborne finish is safer because it doesn't smell as bad or make you pass out but in reality the cross linkers and emulsifiers used to make them work are very bad for your lungs. Good ventilation in your work area is also mandatory, and remember all solvent based finishes are flammable so that should be a consideration in choosing ventilation. Finishing is an entire operation of it's own and usually doesn't coincide with woodworking to well as dust and dirt are it's arch rivals. Spraying the coating is only the first part of the game, if you intend to do nice glossy finishes you will need a way to buff them out, so don't forget that in your budget as well.
Author:  meddlingfool [ Thu Nov 22, 2012 1:15 pm ]
Post subject:  Re: Spray equipment and set up
Bryan,

What are you spraying to be 100% environmentally compliant?
Author:  Heath Blair [ Thu Nov 22, 2012 1:47 pm ]
Post subject:  Re: Spray equipment and set up
Oh man, there are so many things to consider. Now I remember why I chose to brush the first guitars. There's a lot of info there and honestly, I'm going to have to do some research because I don't even understand some of the terms that are being used yet. A turbine sounds like a great tool as I will be shooting in a garage, but definitely out of my price range for some of the better units. Does anyone have any experience with the Campbell Hausfeld HV2002? Not good enough? Here it is:

http://www.cpocampbellhausfeld.com/campbell-hausfeld-hv2002-easy-spray-2-turbine-high-volume---low-pressure-painter/cbhnhv2002,default,pd.html?cgid=campbell-hausfeld-pneumatic-paint-sprayers
Author:  Alex Kleon [ Thu Nov 22, 2012 2:01 pm ]
Post subject:  Re: Spray equipment and set up
I bought a similar unit from Princess Auto about 6 yrs. ago on sale for $99. Not really impressive. I used it twice but the atomization wasn't very good. Got a Wagner HVLP conversion gun next - really nice for $180.
I recently bought the Fuji Super 4 Gold turbine with the EXP gravity gun, and I won't be getting anything else, except maybe the syphon gun. I works like a dream. :D I should put the P.A. rig on Kijiji. Maybe get enough for a pizza !
Alex
Author:  B. Howard [ Thu Nov 22, 2012 7:58 pm ]
Post subject:  Re: Spray equipment and set up
meddlingfool wrote:
Bryan,

What are you spraying to be 100% environmentally compliant?


Compliance isn't necessarily all about the materials used but also the manner in which they are used and the equipment used to apply them. The Devilbiss gun has a certified transfer efficiency in excess of 65%, making it an environmentally compliant gun. You don't get certified efficiency ratings on cheaper guns, like Harbor Freight etc. Lower transfer efficiencies mean more materials and solvents are being introduced to the atmosphere instead of going on the work. Environmental compliance is all about limiting what is put out from the operation in the way of HAPS and controlling how it is released. In the spring I will be installing a certified fan and paint arrestors when I build my new spray booth, this will trap all errant solids and eject vapors in a proper and controlled manner. I am spraying Nitro lacquers and some various polies.They are industrial coatings and are designed to be applied in a production setting with as few extra solvents as possible. They are high solids, so while the VOC content is higher than the consumer grade products most are using, by virtue of applying fewer coats total VOC output is actually lower per mil of dried finish.
Author:  Heath Blair [ Wed Nov 28, 2012 8:06 pm ]
Post subject:  Re: Spray equipment and set up
So at least for now, I ended up with the Harbor Freight 20 oz. 6 CFM HVLP gun. It came with a 1.4 mm tip. Will that handle the KTM-SV that I will be spraying without dilution?

I watched a couple videos on YouTube about the gun and one of the guys was putting everything back together with Teflon tape. Is that standard practice? I've had pretty bad luck with the stuff on natural gas pipelines. It seems to be quite leak prone.

How often should a gun be completely broken down and cleaned vs. just spraying a cleaning solvent through it (i.e. mineral spirits, etc.)?

Also, should any kind of lubricant be used on the needle or other moving parts? I'd hate to contaminate a finish, but I noticed someone putting mineral oil on the needle. Someone else mentioned petroleum jelly.

Sorry, I know that's a lot of questions, but I'm pretty clueless at this point.
Author:  B. Howard [ Wed Nov 28, 2012 8:53 pm ]
Post subject:  Re: Spray equipment and set up
I never use Teflon tape on anything but the air line fittings. A little bit of lube on the needle and pivot points is in order to keep things smooth. Very little is needed and only behind where the fluid / air enter. Cleaning will depend on materials used. Air dry coatings like lacquer & shellac you can rinse thoroughly with an appropriate solvent every time you are done by spraying it clean so to speak and breaking it down every so often. Anything that cures by chemical reaction like pollies (water based coatings fall into this category) or is catalyzed will require a complete tear-down every time and a very careful cleaning or it will clog. This is because any residue missed internally will harden and will not re-dissolve when new solvents / product is run through. Also make sure the gun is rated for water based coatings before spraying any of them. Lots of cheap guns have plain steel parts inside and will rust up quickly.
Author:  John Coloccia [ Wed Nov 28, 2012 10:02 pm ]
Post subject:  Re: Spray equipment and set up
re: lube

It's important to keep the packing lubed or it won't seal right, will dry out and leak...and then your gun will spit. You local auto paint supply shop will have spray gun lube.
Author:  Ron Belanger [ Thu Nov 29, 2012 11:12 am ]
Post subject:  Re: Spray equipment and set up
Check out this thread. Some really good info on using KTM SV by Rolf Gerhard and Randy Muth.
viewtopic.php?f=10101&t=29797&st=0&sk=t&sd=a&hilit=randy+muth
Author:  Heath Blair [ Thu Nov 29, 2012 5:00 pm ]
Post subject:  Re: Spray equipment and set up
Thank you for the info, gentlemen. Now I just need to get out there and do it!

I'll definitely re-read that thread. I know there's a lot I missed in there because I wasn't spraying at the time I read it. Thanks again.
Author:  Heath Blair [ Sat Dec 22, 2012 1:59 am ]
Post subject:  Re: Spray equipment and set up
Ok, I'm back. I've sprayed a fair amount of KTM-SV on test panels and a few coats on the guitar I am finishing. I've ended up with some pretty bad orange peel and this last coat was just horrible. I'm spraying outside in mid 50 degree weather with the Harbor Freight gun mentioned earlier in the thread. I'm not sure what the humidity is outside, but its 40% here in my heated house. At this point, I'd be more than willing to spend $565 on the Mini Mite 3 if I knew it would solve my problems. I'm not so sure though. I can't figure out if my issue is the gun (I do think it's a piece of s), the weather or poor technique. I've tried everything from about 20-60#'s for supply pressure. This last time I used a warm water bath to heat the finish and that was my worst effort yet. What gives?

Is it too cold to even try finishing? Mid 50's is a pretty average high for this time of year. We are expecting rain for the next few days though.

Todd, I know you said the MM3 gives some cushion for dealing with weather. How much cushion are we talking about? Also, even for a hack, am I going to improve quality of finish just by switching to something like the MM3 or am I going to be just as frustrated (more so because I just spent 600 bucks)?

Any other comments or help?
Author:  B. Howard [ Sat Dec 22, 2012 8:45 am ]
Post subject:  Re: Spray equipment and set up
Sorry you are having such trouble. Spraying finishes is a discipline all it's own with a fairly steep learning curve at times. First thing I would like to mention is that getting a coating to flow out like glass right off the gun does not happen, there is always some amount of surface texture AKA orange peel. That is why the surface must be level sanded and then buffed back to a gloss to get that mirror like finish. Spraying outdoors, unless the air is perfectly still, will lead to problems in getting the spray pattern to hit the surface consistently and will cause problems of one type or another. In a booth the airflow is always pulling the pattern toward the surface and clearing the standoff out of the way of the next pass. You mention trying different air pressures but not fluid control, did you try adjusting the fluid needle? Did you try reducing the coating to improve atomization and flow? KTM recomends 1oz distilled water per quart for improved flow. Pattern set up is very important, and is achieved through a combination of air pressure, fluid flow rate, materiel viscosity, needle and tip size and air cap. I would recommend getting the gun set up to spray a pattern about 4" across with the gun at a distance of 6-8" and then start looking at the atomization. If it is to dry, more fluid, too lumpy more air or less fluid. The mid 50's is a bit lower than I would spray at but not unreasonable, however not knowing the humidity, especially when dealing with waterbourne coatings is not a good thing. I also do not like or recommend exterior coatings for instruments, they are typically too soft. Also are you letting the coating dry completely outdoors or are you letting it flash and then bringing indoors to finish drying? The latter can cause the coating to crawl which looks very similar to orange peel. Then of course there is technique. The air cap must remain perfectly parallel to the surface being sprayed. Rate of travel and overlap must remain very constant to provide even coating weight and good flow. You need to operate the gun like a robot, very even and consistent. Most of this will not change very much no matter what equipment you are using.
Author:  bluescreek [ Sat Dec 22, 2012 9:29 am ]
Post subject:  Re: Spray equipment and set up
Lets face it , finish is all about prep and application. I have a cheap gun and a SATA , Sata is my first choice but I will use the cheap gun as my sealer gun and when finishing I may have it loaded with a higher thinned mix.
As Brian points out , don't expect a perfect finish off the gun , you have all the sanding and buffing. It isn't what you put on as much as what you let on. Learning how to apply the finish and use the gun for efficient transfer is the hard part. Not all guns are the same. I learned by spraying cardboard. It lets you see the application shadow . Learning the chemistry and how much thinner and retarder you need are all part of the equation.
Learning to finish does take time. It may take you longer than learning to build a good guitar. I spend a lot of time of finish and prep. 16 to 20 hrs of time between prep , spray , sanding and buffing.
Author:  bluescreek [ Sat Dec 22, 2012 11:35 am ]
Post subject:  Re: Spray equipment and set up
There are a few things about finishing you need to think about.
If you don't have the proper facilities , you need to be aware of the health hazards of the finishes you use. A spray booth is very important , Spraying out side is the next thing . Finishes like Nitro are not just bad for your health , but can be very flammable.
Educate yourself on the material you are using . Many pros out source this work for this reason. Insurance on a shop with a spray booth can cause a large increase in your premium. Also you need to check your home owners policy , if a fire is caused by spraying equipment in your home , You may not be covered.
Author:  Joe Beaver [ Sat Dec 22, 2012 12:09 pm ]
Post subject:  Re: Spray equipment and set up
I use a Devillebiss JGA, with a suction cup, that I bought back when dinosaurs roamed the earth. I spray mostly water based and it has never let me down. Not sure what the price is now but it may be a little out of your budget.
Author:  B. Howard [ Sat Dec 22, 2012 1:08 pm ]
Post subject:  Re: Spray equipment and set up
Todd, I know the benefit of warm spray for lacquers and conversion coats but I have never had any blush issues with a water base finish. Of course I have only dabbled with them on tests and some smaller projects, I do not find them to my liking for various reasons. I was wondering if you still warm the material when shooting them?
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