air compressor for paint job

[rb25crazy]

hey guys

i was wondering what air compressor you guys bought for painting your cars by yourself. i see that a lot of guns require 10scfm.... but, the air compressors to get that kinda scfm are like 1k plus. so, i'm wondering can you do it with a lower scfm? say like 5scfm instead of the 10. i think that if i use a lower scfm that would mean that i'd need to the tank to get filled up more right?

from my understanding you fill up the tank say it's 27 gallons. and then you just use all the air in that but it can be rated at 10scfm right? even though the compressor isn't? so, all that means is that the motor will have to work harder to keep the tank filled or you'd go through the tank and have to wait for it refill before you spray again.

so, let me know what you guys know =D i want to make sure i understand before i go out and spend a lot =D.

thanks

[babowc]

there's a formula to it.. i forgot where i saw it..

you could probably go pick up a husky 60gal unit from homeyD's for <400...
thats what i did..

[rb25crazy]

a formula for what? and damn that's a huge compressor haha, i don't have a garage so i'd like something more portable =D

[punxva]

i've got a 60 gal, and it runs out of breath aka tank is empty before you finish spraying a car, you need either a big motor to keep up with the gun or a bigger reserve...

[babowc]

^RLY?

whats your gun consumption? and what does your tank provide?

[rb25crazy]

ahhh, i see i was thinking the same thing... that scfm thing is how much air is released at once or something. but, it still draws the same air from the same tank at any pressure you set it to. if it's a higher scfm required the air in the tank just goes out faster. so you gotta wait for it to get recharged and then spray again. is that correct? or is it wrong?

[brian m]

CFM(cubic feet per minute) is how much air used at a given pressure(PSI). The higher the pressure you need, the lower the cfm will be. Think of it like this: You can bench 50lbs a bunch of times. Up it to 300lbs(PSI) and you can only do it a couple(CFM).

You need to match the gun to the compressor. Most compressor have a tag rating them = 10.8cfm @ 90 psi, 14.5cfm @ 40 psi. Tools wil be rated also: recommended psi 15-50psi, air consumption 11-14 cfm.

Try to get an HVLP spray gun. High Volume Low Pressure. They put out the same volume of paint as a regular gun at a lower pressure.

[mjjstang]

someone correct me if I am wrong, but cant you just spray till optimum psi is lost and then let it fill up again. If not you could still tape off a panel or two or three and get it done that way. No way am I getting anything bigger than my 33 gallon, that thing has never given me a problem.

[brian m]

You can as long as you time your strokes properly.:keke:















Spraying, not :wackit: you perverts. you don't want run out of air in the middle of a stroke and just spit the paint out instead of misting out.

[punxva]

i'm not 100% sure, on either anymore, but i use a SataJet NR95

[rb25crazy]

yeah, my thoughts are like yours, but i wasn't sure hehe. yeah i dont want anything bigger then a 33 gallon as well, it's to big to lug around =P if you don't have a garage. so that's why i asked if a lower hp compressor can do it. what's the optimum psi anyhow? i'm a noob and havent bought a compressor yet so i don;t know =D and what kinda compressor do you have? craftsman? husky? etc.....

someone correct me if I am wrong, but cant you just spray till optimum psi is lost and then let it fill up again. If not you could still tape off a panel or two or three and get it done that way. No way am I getting anything bigger than my 33 gallon, that thing has never given me a problem.

[brian m]

Check these out:
http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=94667
7.0cfm @ 40psi

http://www.sears.com/shc/s/p_10153_12605_00916762000P?vName=Tools&cName=Compressors+%26+Air+Tools&sName=Air+Compressors+%26+Inflators (http://www.sears.com/shc/s/p_10153_12605_00916762000P?vName=Tools&cName=Compressors+%26+Air+Tools&sName=Air+Compressors+%26+Inflators)
6.3cfm @ 40psi

Both under $400, now just find a gun that will closely match.

As for optimum PSI, that's up to the gun. If the compressor pressure drops below what the gun needs, then it will just spit out the paint.

Don't get hung up on tank size or max psi: here's a compressor with only a 30gal tank!
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91824

[rb25crazy]

oh, i see i see, well most guns i've looked at require like 10 scfm so that's why i was wondering does it really matter if the tank has that amount of scfm. since i was thinking that you could achieve any scfm with any compressor and any tank size. but, the only thing would be how long it could sustain that scfm. that's what i want to know before i get a compressor =D

[CelicaDRIFTER]

i dunno, but i've painted a couple cars with my 25 gallon 5 hp compressor.

only prob is that with a 25 gallon tank, that compressor has to fill every minute if constantly spraying. even more annoying since i have an oil-less compressor.
i want a belt driven one since theyre more quieter.

if anyones interested and local, i have an 80 gallon 7 hp belt driven compressor for sale, 230v. just missing a few things that u can get an home depot or some other hardware store. $350

[rb25crazy]

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=43430
1/4 inch inlet

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90977
3/8 inlet

oh, so there are guns with lower requirements. between these two guns the only differnece i noticed is the inlet size.

would there be any difference in quality between these two guns besides that?

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=94572
this one requires a higher pressure, but it has TWO knobs to adjust with instead of just one like the other two. i'm guessing the knobs probably adjust the spray pattern like how wide or narrow it'll go.

what kind of a spray gun did you get by the way =D so i can compare specs and get what makes sense for me.

thanks for the help

[Def]

Your compressor can be rated at a bit below what the gun uses, but lower than than about 70-80% of the gun's capacity and you will have some wait time while the compressor pumps back up.

[LetsKillKevy]

CFM(cubic feet per minute) is how much air used at a given pressure(PSI). The higher the pressure you need, the lower the cfm will be. Think of it like this: You can bench 50lbs a bunch of times. Up it to 300lbs(PSI) and you can only do it a couple(CFM).

You need to match the gun to the compressor. Most compressor have a tag rating them = 10.8cfm @ 90 psi, 14.5cfm @ 40 psi. Tools wil be rated also: recommended psi 15-50psi, air consumption 11-14 cfm.

Try to get an HVLP spray gun. High Volume Low Pressure. They put out the same volume of paint as a regular gun at a lower pressure.

Definitely agreed on the HVLP gun. If you're going to do your own paint and expect better than average DIY quality on your paint job I'd highly recommend at least a decent HVLP. And again with the tank size I have no problems spraying with and Ingersoll rand HVLP and 30 gallon compressor.

[brian m]

only prob is that with a 25 gallon tank, that compressor has to fill every minute if constantly spraying.


True you can spray cars with smaller compressors...if you know what you're doing. Not saying that anyone doesn't know, but if you've done it before, you know when it's about to give up.

you will have some wait time while the compressor pumps back up.

That's right. It's not always about the tank size, but also what kinda pump is on the compressor.


between these two guns the only differnece i noticed is the inlet size.

The inlet is the same 1/4". It's standard for the smaller tools. I've seen the 3/8" inlet on 3/4" and 1" impact wrenches.

My buddy has sprayed with the first gun and he says it's alright, but the second gun looks better matched for smaller compressors. He's sprayed with HFT guns and all the way up to Biinks (hella baller)

[mjjstang]

yeah, my thoughts are like yours, but i wasn't sure hehe. yeah i dont want anything bigger then a 33 gallon as well, it's to big to lug around =P if you don't have a garage. so that's why i asked if a lower hp compressor can do it. what's the optimum psi anyhow? i'm a noob and havent bought a compressor yet so i don;t know =D and what kinda compressor do you have? craftsman? husky? etc.....


Mine is a craftsman vertical tank. I guess it is 2 hp, pretty weak I guess, but it has done most of the things I need out of a compressor, my CH starter kit blows but what do you want for free?

Obviously I would not shoot until it had proper PSI available, however I would like to know from the pros, is it ok to have wait time in between spraying a section. Like I said if you mask off panels and do a panel or two at a time, it should not be a problem, but if you are in the middle of spraying a panel, can you put the gun down for 30 seconds to let it fill up, or are you risking a bad paint job with flashing etc? pros input? Hope the OP is asking along the same lines, don't want to thread jack or anything.

[rb25crazy]

yeah, that's what im pretty much asking too or along those lines. b/c i don't really see the need for me to spend like 1k on an air compressor when i just want to paint my car and maybe some of my friends cars. not a pro shop or anything.

also, what does "my CH starter" that CH what does it represent, not familiar with it.

[brian m]

Campbell Hausfeld (brand Name)

[brian m]

I know you said that you didn't want a big compressor, but

http://www.harborfreightusa.com/usa/itemdisplay/displayItem.do?itemid=96905

Under $400 and since it's advisable to spray in a garage or enclosure of some sort...maybe one of your buddies could store it for you in trade of painting his car as practice!!

[rb25crazy]

haha that's nice but all my friends live at home with carports =( so, that's not a choice sadly. i was thinking of getting this.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=90977

http://www.sears.com/shc/s/p_10153_12605_00916760000P

you think these two would be a good match up? it sure looks like the compressor can match up the scfm since the gun requires 6 at 30 psi and the craftsman does 6.3 at 40 psi,

[brian m]

Hey, you're catching on. :rawk: The oiless compressors are generally louder than belt style. Overall, it looks to be a good combo.

[rb25crazy]

all with your help brian m! really appreciated. :wackit:

[Sprayandprayz]

most guns require 40 psi(you can spray on down to 20+ though) at the cap which means 60 psi from the tank to the regulator, plus the longer the hose, the more psi you lose. 20 ft is like 10 psi iirc.

[HyperTek]

I have one of these
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93271

One of the capacitors blew up.. and out of warrentee.... Stay away
unless you dont mind the risks.. I actually want to replace it.. Just need to call harbor freight and tell em you have this and its out of warrentee, some managers are cool they will tell you to bring it in and just buy a extended warrentee and they will swap it on spot..

Id paint my car in half anyways... take off the front hood fneders bumpers paint em seperate.. then the only parts physically on the car would be the roof doors and quarter panal

[brian m]

Dang!!! 8.8cfm @ 40psi 230v for under $200!!!

Definitely go swap it out. So you mean all you have to do is buy an extended warranty and they just replace it? Everywhere else would just tell you to order the parts and fix it yourself.:bite:

[rb25crazy]

wow, that's a really good deal if the warranty is that good... i've had bad experiences with warrranty send your shit in, come back the same rofl. it just has a stamp that says "repaired" also, how much is this extended warranty? was this bad boy worth it?

[HyperTek]

well mine is out of warranty and i called em up before, told him it was like 6months old or something, the manager was like "ok thats cool just bring it in and ill let u purchase an extended warranty for $30 or so and ill swap it for you"

I havent done that yet.. but i figure ill just go there and tell em.

I think that capacitor melted because it was hot, so if i get another one ill probably make sure it gets better ventilation.

[rb25crazy]

not bad, but does the extended warranty basically cover anything on the machine that breaks on its own? not like you tossing it over or anything crazy like that. and how long does the extended last btw?

thanks

[SR240DET]

another paint tip is to hold the trigger down on your gun and if the compressor kicks on after a minute in a half to two minutes or more then your good to go. Anything less than that isnt a good idea, but you could still use it.