b-juggles

Hey all,

I was wanting to colour code my bumpers and side moulds. Will a 7.2cfm compressor be suitable for this? I think it is 2 hp.

also i was looking at spray guns and what is the difference between low pressure and high pressure and when do you use each respsective gun?

thanks

Brendan

Dellboy999

i thought 12cfm was needed, and the size of the tank is a main factor for constant delivery of air at the rated CFM.

Low pressure for undercoat, and high pressure for paint I thought, but I am not sure, been a while since I seriously thought of spraying a car.

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73gscoupe

you can use a smaller compressor, just have to stop spraying every now and then to let the compressor catch up. I reckon the problem with smaller compressors in they overheat and give crap air quality when pushed to their limits. probably wont worry you just doing bumpers etc.

use a high pressure gun for everything. the low pressure guns dont give a good finish.

not ford

Those compressors will do what you need to do....just. I bet you're looking at one of the all alloy direct drive jobbies that sell for around $200 new. These are cheap and nasty so don't expect them to last too long if you run the compressor continuously hours on end. What that means is no die grinders or d/a sanders. d/a's really need 20cfm to work properly but 16cfm will be just ok.

gregaust

As mentioned the small compressor will get hot and produce hot air.As the air cools it produces water..You will need a good water trap mounted a fair way from the compressor so the air cools before it gets to the trap or else it will ruin the paint..The smallest would be 10-12 cfm.

ford_forever

depends on the gun - different guns will require different cfm and pressure ratings.

some guns require as low as 7-8cfm some as high as 16 cfm constant pressure .

you should be able to manage the smaller parts with a little persistance and having clean dry air is also a very important factor .

high pressure v's hvlp (high volume air - low pressure) - dosn't mean U only require a small compressor.
Hvlp still requires the same if not more air volume , the difference is once the air reaches the tip(nozzle) with highpressure staying around 40-50psi at the tip , and hvlp only at 8-10psi at the tip which gives a much higher transfer rate(paint to panel) and less overspray than high pressure ..
It dosn't matter with high pressure vs' low pressure they both spray the same material it the size of the tip which need bigger or smaller for different materials , a 1.4 tip is a general size for painting .


a low cfm, high pressure gun with 1.4 tip is what I would look for If I didn't have a good compressor.