Spray painting equipment

Johnny-B

I'm thinking of investing in some spray painting equipment for guitar finishing rather than keep buying spray cans. Can anyone provide advice on suitable compressor specs - pressure and volume, and spray guns?

guidothepimmp

Not sure on the above specs, but equally important to consider is a clean spray area or booth.. has to be damn near close to dust free. Can get pricey

Gearhead

Got my setup really cheaply, although with some nifty handywork. Made the 'booth' as a wall-hung-under-afdak unit with turntable in the floor at 0.8m off the pavement. Got a 1500W compressor with 50l tank and put it (noise) around two corners, running a hose to a second tank (40l) mounted underneath the 'booth'. Finally, the reducer in the line from second tank to gun, using a stainless Devilbiss .7 to 1.5mm gun. The idea is that with guitar spraying you do not need to spray continuously, you want to apply one layer to a whole body before having to wait until the compressor has caught up. You would need a lot more power if you wanted to spray without waiting, but it is not necessary. You do however want to have constant pressure on your gun, otherwise adjusting it becomes a nightmare.
Very happy with the gun, my preference was to get a gravity feed since it empties completely; you will wind up doing small amounts many times.

Johnny-B

Gearhead wrote: Got my setup really cheaply, although with some nifty handywork. Made the 'booth' as a wall-hung-under-afdak unit with turntable in the floor at 0.8m off the pavement. Got a 1500W compressor with 50l tank and put it (noise) around two corners, running a hose to a second tank (40l) mounted underneath the 'booth'. Finally, the reducer in the line from second tank to gun, using a stainless Devilbiss .7 to 1.5mm gun. The idea is that with guitar spraying you do not need to spray continuously, you want to apply one layer to a whole body before having to wait until the compressor has caught up. You would need a lot more power if you wanted to spray without waiting, but it is not necessary. You do however want to have constant pressure on your gun, otherwise adjusting it becomes a nightmare.
Very happy with the gun, my preference was to get a gravity feed since it empties completely; you will wind up doing small amounts many times.

Thanks GH for the information. I'm not sure that I completely follow the logic so I'll try to clarify.
1. A 1500W compressor with a 50l tank is insufficient to maintain pressure to spray continuously at the volumes required by the spray gun.
2. You have added a 40l tank to give you a total of 90l reserve capacity.
3. As you spray the compressor is insufficient to keep up the required pressure on its own but the pressure from the running compressor plus the 90l reserve is enough to hold sufficient pressure for the 30 seconds or so which it takes you to completely spray one coat without losing enough pressure to have to adjust the spray gun.
Did I understand you correctly?
What is the need for the reducer?
Where did you source the second tank and what would this cost?
Adendorff has a 1.5kW 24l for R1095, 1.5kW 50l for R1495 and a 1.5kW 100l for R2395. Is this the right ballpark pricing?
Is the proximity of the tank to the booth an issue?
I presume that if I bought a higher power compressor with a bigger tank, the pressure drop wouldn't be an issue but this would obviously cost more.
Where did you buy your spray gun?
Does this spray gun look like to right sort?http://www.tooltime.co.za/ProductDetails.aspx?id=4056
Thanks again for the advice

Gearhead

The first step is to understand the importance of constant pressure. The adjustments on a gun are very simple valves that only give constant airflow (what you want) when under constant pressure (that you must give the gun). The easiest way to make constant pressure is to make too much pressure (say, 6 bar) in a tank and then to put a reducer (a thingie designed to let constant pressure through). If you would set the reducer to 2.5 bar and let the tank empty through the reducer, it would give 2.5 bar until the tank was only at 2.5 bar, and after that give as much pressure as there is left in the tank. Good. Understood.
Second step is to understand that the hose length between reducer and gun should be not more than necessary to do the work. Mine is about 2.5m but I guess 4m would still work. 20m won't.
Third step is to understand that with a certain compressor design you can only hook up so much tank volume (or guns). Even if the compressor can seem to keep up, it might run hot because it was intended to do short bursts.

I got annoyed with the noise of the compressor and wanted a long hose length, so I pulled the trick with the second tank. The combined tank volume is not too much more than the design size (I checked if the compressor does not heat up too much) and due to the volume close to the reducer it can still hold pressure really well. This is not necessary if you get proper earplugs or something.
You can probably get a second hand tank at a place that services trucks and trailers, they get used in brake systems. Again it is only for those who are anal about their ears.

I don't know enough about guns to see if the one from your link is any good. I went for an A brand and (since I wanted to paint water based as well as thinner based) for stainless but that is because I believe in buying tools once. About as important as getting a good gun is keeping it clean; take the thing apart and soak/brush/wipe until it looks new after use.