spray gun?

[Micha Schellhaas]

I'm looking to purchase a spray gun and all the neccesary equipment.

It's not so straight forward to find ot what you should by, what kind of gun, kompressor, turbine,....

Anybody has experience to share? Thanks and happy holidays!

[RETROROD]

I was more than once told through my life....."Buy the best that you can afford"......'generistically speaking':....of course!

[Micha Schellhaas]

Haha, of course :-) I am trying to find out what's the best... :-) I'm thinking the folks here can share their experience and point me towards what I should be looking for...

[Frank Ford]

We switched to the German-made SATA system a couple of  years ago - it's great.

[Micha Schellhaas]

Thanks Frank! I'm german too so that appeals to me instantly, it might be out of budget range I'm afraid

[Peter Poyser]

Hi!

I favour the Devilbiss Sprayguns.

You can usually adapt them to Line Feed Pots or Suction Feed Pot.

If you go for a Gravity Feed Spray Gun then its Design will dictate that particular use, but it's a good choice.

Although many people might understandably prefer far Smaller Spray Guns and Pots in Small Shops, the Easy Serviceability of High Productivity, Industry Standards, and the User Flexibility of these Tools is such that there is practically, very little an extremely experienced Sprayer, cannot do with them.

But that's just me. And my View..

http://www.devilbiss.com/products/spray-guns/manual-spray-guns/hvlp

 

 

There are plenty of perfectly useable, far cheaper Spray Guns on the Market.

But its Spare Parts for them you may find is the problem getting.

Take care of your Needles, Fluid Tips and Air Caps.

Devilbiss is an Industry Standard Gun.

 

 

If you are in America, perhaps others can best advise you of the Local Compressors available.

But in short, I would be looking for a Belt Driven as opposed to a Direct Drive, where the Electrical Motor is completely separate from the Compressor itself.

Get one with the largest Cubic Capacity of Compressor Unit and the largest Cubic Capacity of Air Tank that is both Affordable and Practical for your Shop.

Usually they benefit greatly from a superior Air Filter from the Tank due to Compressor Oil, and also a Water Trap for the Line.

Ask about Spare Part Kits and get them when you buy the Compressor.

http://www.clarketooling.co.uk/tools/Professional_Air_Compressors.html

 

If you can't get Spare Parts when you Buy, continue looking.

 

Good Luck!

 

P

[Micha Schellhaas]

Thanks! that's a lot of good info. I'll check it all out! :-)

[Russell Vance]

HI Micha,

You will note that SATA and Devilbiss come up as very expensive items - we use Anest Iwata 400 Pininfarina guns which are the equivalent to SATA and the higher level Devilbiss guns - they are also as expensive as poison to buy initially. 

But, all these guns deliver exceptional results, will last much much longer than average guns , and they are supportable, repairable  and adaptable.  If you are only going to spray a couple of guitars a year for yourself and friends these choices are a luxury - anything more than that and they start to become a necessity - the difference in consistency and quality is that noticeable.   

The amount of time saved by not having to scrub and sand endless orange-peel, inconsistent lacquer build  and runs etc is also another reason these guns become more economical over time and number of guitars produced.  Peter's precise observations about air source and quality cannot be overstated  - the best gun in the world will crash out with bad air.   If you have to make a decision based on a fund limit, the Develbiss range has good cheaper options as does Anest Iwata.   SATA is always a bit of a reach but the quality is undeniable.

Hope this helps, Rusty.

[Micha Schellhaas]

Thanks! yes, that helps! Thanks a lot. I'm too late to put the order in with Santa, his sleigh is already packed for this round, but I'll come up with the funds myself and give Santa a guitar for Christmas next year :-)

[RETROROD]

Merry Christmas to you!!

[Peter Poyser]

As this is a New Installation.

I thought it might be helpful to share a few Spraying Tips.

Buy a pack of Bottle Brushes, Long Thin tough little Brushes for Cleaning Purposes.

Make  a Large Stainless Metal Tray or some kind of Cleanable, Cleaning Area that can be brought into Play Easily.

Think SAFETY & VAPOURS. Make sure this Area is Well Ventilated, and if you have any Inflammable Cleaning Products invest in SEAL SHUT Flam Bin. Basically if you use Inflammable Liquids for Cleaning Purposes, you don't want Dangerous Fumes escaping from the Container or Implement  all the time, and building up in an enclosed Area.

Cleaning Thoroughly is an important part of the Spraying Process. Be able to Strip your Gun Down to its component parts, clean and reassemble it without dropping or losing anything. Guns can crack internally between their Machined Chambers if you drop them, so don't. Keep some vaseline for a little on the Rear Section of the Needle that Slides into the Packing at the Air Valve on the Handle.  Think the Back of the Gun, Needle, Spring, Adjustment Screw to Grease. Buy a Gun Spanner, with all the various different sizes available in one handy tool.

 

 

Try to get your Spray Gun Pattern Optimised.

In order to achieve this you need to Balance the Viscosity of the Material, with the level of Air and the Material Flow of Paint. One is a Paint Mixing Issue. The other two can be adjusted at the Compressor Filter Valve, and again at the Gun via the Spreader Valve which adjusts the Width of the Spray Fan and Trigger/Needle Travel Adjusting Amount of Material Flow.

Get used to Pulling the Trigger halfway, so that Air is fully on, but No Paint is Flowing, and Practise gently introducing the Paint by squeezing the trigger further, and Spraying as much as you want, where you want it, in gently flowing movements upon some Practise Material. Let your eyes do the work, and be able to switch the trigger for Paint Flow On and Off at the beginning of Paint Strokes, before and after the job, (when Gun is no longer pointing at what you are Spraying), whilst Moving the Gun Up or Down with each stroke, overlapping the strokes as you cover the Whole Area.

After you are competent at that, you might like to try to develop a style that Switches On and STAYS ON, continually moving forward over different areas of the job, moving the jobs position or your tool in relation to it ALL the time, and never going back on yourself ever (when the Gun is actually pointed at the Job and applying Material). If you do, you will get a build up of thicker material at that point, so go past the job "always" with this technique. It might seem like incorrect technique, but there are certain advantages to working like this, later if you can do it well. As there is less time for contamination and dirt to fall on the job while its hanging about.

One of the big problems Sprayers have, is blobs or gun spits shooting out over, or falling onto the Job, they are Spraying, while they are Spraying it. Once this happens you have a build up of "Polishing Out Problems". But these difficulties can largely be minimised or avoided altogether.

Often these problems are caused by incorrect Gun Adjustments, Poor Cleaning and Gun Maintenance, or simply by Not Watching what is happening at the Gun itself, because the Sprayers Visual Attention is preoccupied, monopolised with looking at the Job itself and the Finish being Applied. The type of problems that can commonly occur are follows.

If the Fluid Tip Needle Seal is not Absolutely Correct, then a build up of Material can occur at the Fluid Tip (out of sight of the Sprayer) Don't look directly at the Gun pointing it at yourself, but look from time to time from the side of the Air Cap at the Fluid Tip so see there is no Build up of Material. This can happen over a while, especially during the Spraying Process, then suddenly as you introduce Air by switching the Spray Gun on, it then blows the built up Material over the job in blobs.

So watch the Air Cap, keep a Clean Rag with a little Thinners to wipe it if need be, and get in the habit of turning the Spray Gun away from the job, and releasing a little Material, just prior to actually Spraying, this wastes a tiny bit, but clears any built up Material from the business end of the Gun by blowing it clear. If the Gun is Badly Maintained, such a build up might occur during Spraying or even as it hangs waiting to be used, but if you watch for it, you can STOP. Clean the Tip and Clear the Potential Problem, before it occurs, and then carry on, it just takes a tiny moment, and means watching the Gun as well as the Job itself. But will stop most all of the Blobs!

Other areas to watch for are, the Top Air Hole in a Suction Feed Pot, where Paint can easily build up, and you have to exercise care in the way you angle those Guns to prevent that causing a Blob dripping onto the job. A Gravity Feed Gun should have a Paint Filter that fits into the bottom of the Pot where it meets the Gun. Make sure this is clean and ok, otherwise thicker material or even building sludge might shoot over the job and cause Blobs. This will also have a similar Hole in its Top that can be  a problem. Also watch the Packing Material Adjustment Nut on the Guns Air Valve. If it's too loose, Thick Paint Material can build up there and drop onto the Job causing Blobs. You don't want it too tight as it has to allow the free movement of the Needle back and forth, but if it's too loose, Blobs can result. Generally I tighten the Packing Adjustment Nut until it begins to restrict movement, then back off to loosen it a little, to create a Tight Seal but that allows free Needle Movement.

But if you follow these thoughts through into practise, all your Blob Problems will probably never occur in the first place, and that will avoid and solve a lot of Problems before they Happen.

 

People often concentrate a great deal on Air Pressure.

What you need for Spraying, is not Pressure so much though it is Important, what you actually need is a Continuously Available Supply of a Large Volume of Air at the Correct Pressure.

Take no notice of people that advertise or try to sell High Pressure Spraying Equipment Cheaply. The High Pressure is obtained simply by severely restricting the Volume of Air. And what you need is a High Volume of Air.

The Air Pressure your Compressor Valve Gauge will tell you are getting is probably pretty meaningless. A good Charcoal Filter and Gauge is expensive. So set it as High as it will go, or around 100 PSI, if you are using an Air Pipe that is 15' - 25' feet long.  This will give you around 40 PSI at the Air Cap. This is the kind of Pressure you probably need. The longer the Air Pipe the Greater the Pressure Loss at the Air Cap.

You can buy Spray Gun Air Caps with a little Tube and a Valve at the end of it to give you a Correct Reading of the Pressure at the Gun. Or you can trust what I am telling you, with a Pipe of about 15' 85 PSI or above should work well, with a Pipe of about 25' 100 PSI at least for sure will be needed. I would use it at 100 PSI either way, because I prefer a Finely Atomised Finish. Although you can make up your own Air Pipes to a length to suit you and 15' is probably a sensible length, you may find you can buy readymade Pipes complete with fittings available locally, but these may be in the Longer Lengths, so that is why I mention that.

In any case, buy some extra Male and Female Fittings, you never know when they will wear out and need replacement. When you clean your pipes with some little thinners, do not allow Thinners onto the Pipe Fittings themselves. It will ruin them and they will not function properly or give unnecessary problems. Do Not leave your Spray Gun in Thinners to make it easy to clean. All you will do is "perish" the Packing Material, especially if the Cleaning Thinners are Strong, and cause it to wear prematurely and need replacement, or cause the Blobbing problems to happen as described earlier. Similarly be careful if any Rubber or Nylon Washers, or other parts that are involved.

If you need to Heavily Clean an Air Cap for instance, remove it from the Gun to let it soak. Generally I try to avoid Guns with Rubber, Nylon and Plastic Parts other than the Pot which can be Plastic, but watch out for Rubber Rings, Seals and Grommets, which you might find here and there, learn and remember what goes where.

 

 

Here is a Spraying Fan Pattern Trouble Shooting Chart.

Get Sheets of Thick Brown Paper taped to the wall and observe your fan pattern with a quick discharge of Material from the Gun at the Paper. Adjust your Gun Correctly.

http://www.vivilon.com/pdf_articles/GTi%20pray%20Pattern%20Poster%2...

 

When you Spray, there is the Viscosity of the Material, the Air Pressure, the Flow Rate Adjustment, Trigger Travel, the Width or Narrowness of the Fan Pattern itself, the Distance the Gun is from the Job, and the Speed with which you Pass Over the Material. I like to think of all these separate factors as being a kind of organic, living thing, as they all interact and affect each other as you Spray. So if the Material is Right, and the Gun is Setup and Adjusted Correctly, basically your eyes can do the work as you watch the Material as it is being applied.

Usually, it is a good thing if Inexperienced Sprayers keep the Gun moving fairly quickly, so as to prevent runs occurring or heavy build ups of material at a particular points with accompanying weaker Areas..

Applying multiple thin coats of Material and gradually building the Finish, up to the desired look and thickness is a good way to begin. Please be aware that a full Spraying Patten Width could be 18". It's easy to apply Material to one part watching it carefully without realising that an edge of the pattern at either end is placing Material on an area that is getting HIT Multiple Times as different parts of the job are Sprayed. This is how runs happen.

You may find that Beginning with the Most Difficult Areas to Spray. As well as the Edges of the Job, is a good Plan to Follow. Edges can be places where Finish from two directions or more are overlapping. It's easy to get build up, yet Material also conversely thins, falling away precisely at edges, so the build up can be just before the edge either side although it seems to be at the edge. Don't be afraid to waste some Overspray of Material putting the right amount of Material exactly where you want it to be, and realise that some areas simply get hit by Overspray repeatedly, so don't actually need Spraying directly at all, dependent upon how efficient your Personal Spraying Pattern for any given Process or Operation is. What I find is that if I have done all the awkward and complex, potentially problematic Areas, the rest is really simply applying a straightforward coat, so relatively easy. Imagine trying to place paint in difficult to reach areas, over  a wet coat already applied, without causing any additional problems whatever to the Finish.

That's not the way to do it. 

 

Do all the difficult stuff first, then apply a Straight Forward Even Finish over the Flat Surfaces.

During my life I have had to Apply Paint Material in places that are completely Impossible to Paint Directly.

You can only Paint Them Indirectly, by bouncing Paint Back Off from other close by Areas, sufficient to provide adequate coverage for the place that can't actually be Sprayed.

Avoid thicker build up in Areas or Weakness in Others, Go for an Even Looking Coat of Material All Over. You may want to achieve this by the means of Several Coats applied with Relatively Fast Moving Strokes. That would be too much work for me, but is a good way to get a Fine Looking Result, without any problems with a bit of luck.

Watch your Temperature and Humidity. And you might want to finely sprinkle a little water on the floor around the Job to help with that and reduce air borne dust, if you can do so without slipping an hurting yourself. Dependent upon the Material you use and the conditions under which you are Spraying, you may find it helps quite substantially in certain environments.

 

 

P

[Micha Schellhaas]

Peter - WOW thanks a lot for this extensive answer! It is very much appreciated!

I am soaking up this info and have been reading it several times! :-)

Would you mind if I repost your article on my guitar blog www.theaxeblog.com ? I will document how I set myself up, my instruments etc there. The goal of the site is to become a good resource and fun to read for guitar interested folks. And your little article will be really worthwile for a lot of people!

[Peter Poyser]

Hi Micha.

Use the info how you wish, it will genuinely help people avoid many commonly made errors that make Spray Finishing extremely difficult. I post for fun and keep a low profile on the Internet.

So please, rather than mentioning me, Strongly Highlight Frank Fords Great Fora here, that have so many Highly Experienced Luthiers of Long Standing that contribute so very much, and The Treasure Trove of Franks Resources on FRETS. COM.

 

Place a link to the "Fora" and the "Resources" to Spread and Build the Sites as the Number 1 Resource.  

http://fretsnet.ning.com/forum

http://www.frets.com/FretsPages/pagelist.html

 

I like the Fact that there is a High Information to Noise Ratio on Franks Fora.

Whereas all other Guitar Fora's generally suffer greatly from a High Noise Ratio compared to the Solid Information Signal.

Its Frank Ford and the many Great Luthiers hereabouts that really make this site the "Jewel in the Crown" of Reliable Data on Musical Instrument Construction and Repair.

 

They deserve the Full Credit, for Making the Site, the Tremendous Resource it is.

 

I hope you had a Great Christmas!

 

 

P