Spray equipment

[fender3x]

I have been admiring the amazing paint jobs that Phrozin has been doing, and envying those with good spray equipment. This has me wondering what the minimum is that one would need to do spray jobs.

One problem for me is that I am having trouble converting the specs that I see when folks talk about their compressors. I am not sure how to convert my compressor's SAE specs to metric. I am not sure why the compressor does not supply both...it's made in China after all.

My compressor is rated at:

.8 hp
150 PSI max
6 gallon tank (that I can convert... 22.7l)
2.8 SCFM @ 90 PSI air flow capacity or 3.4 SCFM at 40 PSI

I am guessing that it is too small for spray equipment larger than an airbrush, or maybe just on the edge.

Would be curious how much of an upgrade on compressor I'd need and what other equipment would be necessary?

[McCreed]

Hey fender3x.

I'm far from an expert on this, but I'll share the experience I have with my current set up.
First I'll mention that I downsized back in January after moving to house that has a smaller workspace than I used to have.
So the basic specs on my new compressor are:
1.5HP motor (oil-free, silent)
24 L tank (6.34 gallons)
Free Air Delivery (FAD): 110L/min (3.88 CFM)
Max. Pressure: 8 Bar (116 psi)

I have only used this compressor with my HVLP mini-gun (.8mm tip) and so far have only sprayed necks.
It has plenty of pressure and flow and doesn't cycle to where I'd consider it excessive.
I have a larger HVLP gun (w/ 1.4 - 2.0mm nozzles) which I used with my big compressor (since sold it) and I only ever used the 1.4mm nozzle with ac lac in that gun. I'd be interested to see how the little compressor handled it, but at the same time, I have no need to use the bigger gun even for guitar bodies. The mini/touch-up gun is absolutely fine for that. I wouldn't consider painting a car or house with the new compressor, but I didn't buy it for that anyway.

In regard to your compressor, I think it would be "just on the edge" as you put it. I'm under the impression that 1 HP is the absolute minimum for this application. I know it's only .2 HP from yours, and maybe it would be OK, dunno. As I said, I'm not an authority on this subject.
Maybe it would handle a mini/touch-up gun just fine, but cycle more frequently... (???)
It might be worth just buying a small spray gun and giving it a go. You can get a small spray gun in the US for peanuts, and it's not like you're setting up for mass production and using the compressor for hours on end every day.

Hopefully a real expert will reply here...

[fender3x]

Thanks! I'll see if I can find a decent small gun. No rush...I'd be for the next project anyway, and I have at least two in the cue before that.

My clear says it likes to be done with a gun...and I have been thinking of using either one of their pre-mixed stains or a 1lb cut of garnet shellac. Speaking of which, when I use the shellac with a brush I don't actually clean the brush. I just let it harden until the next time I use it, and then I let it soften in alcohol. Would I need to do anything special to clean a gun?

[Rabbit]

What you have would work just fine with a 1mm mini gun. A full sized conventional gun (not HVLP) you could probably manage a coat on a guitar, then you would have to wait while it fills the tank again. With a small compressor, you should stay away from HVLP, they are air hungry (the HV in HVLP refers to the high volume of air they use, the advantage is HVLV guns generate less overspray, so less waste) To clean the gun properly you will need the correct spanners to remove the nozzel, some small tube brushes and the appropriate solvent for what you are spraying. for automotive solvent based paints and clears that's usually general purpose thinners, but there is also special gun cleaner (expensive) solutions. Water based systems use water based solvents for cleaning, usually whatever you use to thin the paint.

[McCreed]

With a small compressor, you should stay away from HVLP, they are air hungry (the HV in HVLP refers to the high volume of air they use, the advantage is HVLV guns generate less overspray, so less waste)

Rabbit, I think you meant LVLP, not HVLV. Dunno...

Also I'm not disputing Rabbit's comment, but based on my own experience, the HVLP mini-gun works just fine with the compressor I detailed above.
And I don't think overspray is as big a concern when you're spraying small areas like guitar necks & bodies as it would be doing large flat(ish) areas like car panels.

FWIW, if there are budgetary concerns, the LVLP guns seem to run about a $100 dearer for some reason.

[Rabbit]

Rabbit, I think you meant LVLP, not HVLV. Dunno...

Also I'm not disputing Rabbit's comment, but based on my own experience, the HVLP mini-gun works just fine with the compressor I detailed above.
And I don't think overspray is as big a concern when you're spraying small areas like guitar necks & bodies as it would be doing large flat(ish) areas like car panels.

FWIW, if there are budgetary concerns, the LVLP guns seem to run about a $100 dearer for some reason.

I direct you to : https://www.prowin-tools.com/applica...vlp-spray-gun/

note the air volume difference. But with a mini gun it would be less of an issue. Just like the price of full size guns, price of mini guns can also vary dramatically from $20 to over $500. I mostly use star mini guns, which are probably at the lower end of mid range. Not all the bells and whistles, but it works for me. As for the nozzle size a lot depends on what you are spraying. 0.8mm would need more thinning for what I spray than the 1mm I use mostly. I have a 0.8mm, also a 0.5mm (you are hitting air brush territory there). Admittedly you don't need to be as extreme as me, I use 3 x 1mm mini guns, a cheap and nasty one for primers, and separate ones for base coat and clear coat. With good house keeping one will do.

[Trevor Davies]

I purchased a 1 hp, 24L, oil free compressor last year, with a Star 0.8 mm mini touch up gun (S-106T). That seems to work well for doing guitars (but I'm still learning how to use it).

Interesting that at the shop I got the compressor from, they said for spraying I would need a much larger (and expensive) compressor (even though I showed them the specs of the gun).

[Simon Barden]

You might be better off with a larger compressor if you were spraying cars, or a conveyer line of production guitars, but a single guitar doesn’t take much spraying at all before you’re finished. The motor run time cycle is important, and most compressor motors are rated for a 50% duty cycle (50% on, 50% off). More than 50% and the motor can burn out. But you’ll probably have the compressor run once for a couple of minutes when spraying, and then you’ve finished and it’s probably 30 mins or more before the next coat goes on. So your worst load cycle is probably no more than 10% and generally less.