Compressor for LVLP gun and mask

[Grrrmachine]

I'm still pricing up the gear to attempt my first paint job, and I've read the warning on 2k paints. Because my car is metallic, I'm forced to use a 2k clearcoat, so I'll need an airfed mask to do that.

The car will be painted in stages anyway (ie, all doors, wings and bonnets removed) because of the size of my lock-up, so I don't need a HUGE compressor, but all this CFM and psi stuff has foxed me a bit. So, to summarise:

To run a gravity fed gun on a 1.4 nozzle AND an air-fed mask on one compressor, what minimum specs do I need in terms of horsepower, capacity, CFM and psi?

 

[big patto]

you will need a good sized comp mate i run a 14cfm pro comp and it wont keep the two going and thats the largest you can run on a houshold supply or so i am told any larger and you start to dip the neighbours lights, reckon you would have to go 3phs, its the mask that takes the air,

 

[Grrrmachine]

thanks for the tip. I'm not sure about how to combine two things at two different pressures; the mask is 40psi minimum, while the gun is only 20psi for LVLP. The two together have a flow rate of nearly 15CFM, which I can see is far beyond what a typical 3hp 240V compressor can cope with. And a 150l tank would run out in a minute and a half even with the motor running flat out.

I might have to look at having two compressors then.

 

[brightspark]

you will need a good sized comp mate i run a 14cfm pro comp and it wont keep the two going and thats the largest you can run on a houshold supply or so i am told any larger and you start to dip the neighbours lights, reckon you would have to go 3phs, its the mask that takes the air,

18cfm can be run of a 240v supply running a 4hp motor. fuse rating at 40 amp the start up load may pull the lights down a little depending on where u are in the line but isnt a problem

 

[Grrrmachine]

I'll keep my eye out, but I'll admit my nervousness is starting to wane. The only big areas the gun will have to spray will be the roof and the bonnet, so as long as I wait a minute or two, the tank should fill up and I can keep spraying.

I know the mathematical technicalities are far more complex than this, but if the pump I end up with only chucks out about 11 CFM, the mask sucks 6.5 CFM and the gun is 8.5 CFM, I should be able to spray in bursts and let the motor fill the tank back up while still breathing through the mask.

 

[Chipper]

Chances are a 3hp comp will put out around 9, 9.5 cfm FAD.

Its the air throughput you need to know i.e. the cfm, more than the psi, to best get an idea of demands etc. Masks seem to want around 7cfm, a gun probably thereabouts too.
So no chance of driving a gun and an airfed mask off that; I've got one and have a separate comp which'll be used for air fed mask.
Also the comp would have to be located well away from where yr spraying, and filtered etc etc so it doesn't draw in overspray clouds and punt those into yer mask.

You really don't want to be taking chances, spraying in bursts etc and hoping the mask is still driven.

But you could always use 1k clear, OK it won't be as durable as 2k but all depends what you need. Or celly. Avoid all the hassles.

 

[Faaluke]

I have a 3hp compressor that puts out 11-12cfm (rated at 16cfm), but cheap ones i've seen are around the 9-9.5cfm as you mention. So I guess it depends on the quality of the compressor.

 

[mike os]

as I understand it it is critical that air pressure to the mask is maintained at all times if it is to be effective.

 

[Grrrmachine]

Yeah, this is what I understand about masks too; positively pressured, so that the air leaks out of the sides and pushes any toxins away from the mask.

I know the only sure-fire way is to get an awesomely large compressor, but that's just not really feasible. But I'll give what I have a try on, say, painting a door skin or a front wing, and if the mask doesn't work, I'll pick up a smaller second compressor dedicated for the mask only.

 

[Chipper]

You'll definitely need a second comp. No way will you properly power a fullsize gun and mask off 9ish cfm.
Mask ~ 7
Gun ~7
It just does not add up.

Mine's not a cheapie, but 14cfm displacement, 9.5 delivered. 3cfm per hp is a decent rule of thumb. You also want to be slightly cynical about figures and allow a margin.

 

[big patto]

i have a pair of clarck se16c150 which work ok gun on one an mask on the other, as said its all about the cfm beaing able to keep up with the tools, after about a couple of mins the gun drops and the mask drops air and steams up,

 

[big patto]

and if you go to machine mart on a vat free night you can get them cheaper mine were £379 without the vat had no probs with this.

 

[mike os]

You also want to be slightly cynical about figures and allow a margin.

only SLIGHTLY???? I swear they make these figures up when asleep after a good session on the amber nectar

 

[tux]

I may be wide of the mark here, but to avoid 2K clear (and therefore an airfed mask), single pack RFU clear is available. I have no idea what the quality or longevity is like (I suspect nowhere near as good as 2K) but it may be another option. Then you would only have to worry about air for the spray gun.