Hi all im new here so excuse the question.

Ok i need to buy a compressor as I want to paint my POntiac fiero.
Ive sprayed one before useing a friends 5HP with a 100 Litre tank and that was fine I was happy with job.

BUT

I cant afford that compressor so im looking at a 3 HP 100 Litre tank compressor. My questions are as follows

1- Will this run a HVLP gun

2- If i buy a LVLP Gun and say the gun runs at 30 PSI and needs say 6 CFM, and according to the compressor it gives a higher CFM at 30PSI will this damage the gun.

No one in New Zealand sells LVLP guns and no one can answer this question for me and im getting crazy about it.

I was also told today from a painter that most paints will not shoot right running at 30PSI.
Im going to spray Base coat clear coat, Single Pack. useing Dupoint paint ( not cheap )

thanks heaps

No it will not ruin your gun. Scfm is the amount of volume ready to be given at any point in time at that psi setting.Setting the psi on your gun with a regulator will keep it safe and your gun will only use what it needs to use depending on your gun settings. As far as will a hvlp work with that compressor it depends on the amount you're painting in one session. I.E a few panels vs a whole car.

excellent thank you i cant believe i couldnt get this answered here. so if the compressor has a regulator i dont need one also at the gun?

also what about the comment some paint will not paint at 30 psi or 29psi
my understanding is thats crap as long as the gun does its job with atomizing or whatever its called lol

Yes you definitely want to run a regulator at the compressor and gun. You'll have a lot more consistent and cleaner sprays out the gun if you do it this way. As far as what psi to set at the compressor there is actually a math to this given the size of your hose what gun etc Etc but a general rule of thumb is to set your Compressor regulator 2x's the psi you set you Gun regulator at.

as far as your "30 psi" question . That totally depends on the gun wether that is too much or not. I run close to 30psi when spraying clear and it sprays beautiful all day. So just check your manufactures requirements

My opinion
No this is too small with the information provided
Do you have a picture of the data tag or a link to the add for it?

It amazes me constantly the size of the compressors used by the guys in North America. 60-80-100 gallons. and always big horsepower.

By comparison I use a 2.75hp (240v 15A) compressor with a 50 litre tank. It copes with all my guns, being able to deliver 14cfm (although nominally rated at 17cfm) and really only struggles with some air tools. Admittedly the air here is relatively dry but I don't have problems with moisture, so long as I drain every day or two.

This, although a different brand and a bit cheaper, is similar in spec to what I use:
http://www.gasweld.com.au/air-compressor-belt-3-0hp-alloy-twin-pump-17q-copper-wound-motor-procraft

If you're going to be using LVLP gun(s) then a compressor like this will do it on its ear. Even RP guns (a better choice IMHO) will not tax it. I use a Tekna Copper on bigger jobs and no problems with air. The compressor runs, of course, but not constantly, and shuts off almost as soon as I stop spraying.

You do need to consider the size/capacity of your compressor when buying guns. I have no need to use HVLP (not mandated here) so I don't, but some of those would push my compressor to its limit.

radar wrote: If i buy a LVLP Gun and say the gun runs at 30 PSI and needs say 6 CFM, and according to the compressor it gives a higher CFM at 30PSI will this damage the gun

No, it won't hurt the gun, which will only take the volume it needs.

As noted above, you control the pressure by regulators at the compressor and at the wall, not at the gun. Use a removable pressure gauge at your gun inlet to set a regulator at the wall of your booth, then remove it. This removes restriction in the line and weight from your wrist/arm and keeps your gun balance the way it should be.

NFT5 -
Remember that most of the hobbyist painters in the USA are painting from home (in a garage or shed), where the nominal voltage is only 120V and a limit of 15-20 amps at the breaker in the electrical panel. As a result, the pumps on the compressors are limited, and the manufacturers try to compensate by using larger tanks in lieu of actual compressor output. Also, the cost issue is in play here - the air tanks are cheap compared to the pumps.

Radar -
If you run the spray gun at a higher PSI than specified, you can potentially damage some of the seals. More likely, though, is that you will over-atomize the paint, and the pattern will "blow-out" in the middle (very heavy ends and almost no paint in the center of the pattern).

1MechEng wrote:NFT5 -
Remember that most of the hobbyist painters in the USA are painting from home (in a garage or shed), where the nominal voltage is only 120V and a limit of 15-20 amps at the breaker in the electrical panel. As a result, the pumps on the compressors are limited, and the manufacturers try to compensate by using larger tanks in lieu of actual compressor output. Also, the cost issue is in play here - the air tanks are cheap compared to the pumps.

Thank you for that. I probably should have realised but that explains the discrepancy. Mine needs a 15amp power point at 240 volts, so obviously a lot more power available.

Also explains why my booth exhaust seems to have ridiculously high capacity compared to what's generally quoted on here. 15 amps at 415 volts, 3 phase.

I love this topic. Ive used some high profile guns on low PSI situations with minimal CFM and I will tell you makes a big difference when you run these guns the way you should.

Big HP doesn't mean you have everything you need. I currently run a 30 GALLON 6hp setup at my home shop and the cfm is set at 11.5 which is pretty high. Will do some great work. Yes the compressor turns on fast but if your doing bumper jobs blends etc this setup will work fine.

Now if your doing overalls all the time you will need some high CFM to get that constant gun flow.