Abubaca

iTrader: (3)

As I contemplate a DIY paint project on the ole warhorse, questions arise. Many I can find answers to, but some are just easier to simply ask someone. With regard to air compressors, many many different places will tell you need a CFM rating higher than what the gun requires, (which of course makes sense) and then as big of a tank as you can afford. Here's my question, if you've got a compressor that's a solid 3 or 4 CFM above your gun's requirements, can you get away with a smaller tank? The only info I can find on this was on Youtube, and the guy said if your tank is too small your compressor will run non stop, which can be annoying and can overwork the unit. ...but if you're only painting ONE car? In your garage? ....would a 30 gallon tank be a reasonable solution? I can afford, and will use a high CFM, 30 gallon air compressor. A larger 60 gallon + compressor is a lot more expensive, would only really be needed that one time, and frankly takes up room I don't have.

GarageToys

iTrader: (6)

I have a 20 gallon compressor and have painted a couple cars with it. It's a hand-me-down and my Dad had painted dozens of cars with it before i got it. Granted, it is not ideal, but I've found that it doesn't run nearly as much when painting as it does when using air tools. My compressor sucks for air tools. To paint one car, a 30 gallon will be fine.

Abubaca

iTrader: (3)

Sweet. Thank you for the reply.

TransamGTA350

iTrader: (2)

I have a 26 gallon compressor and it is reasonably ok for painting. I did not paint the outside of my car, but I did the underside and engine bay and didn't have an issue. The compressor ran the whole time. I also used a water separator and an in-line filter/dryer at the gun inlet.

If you are doing the whole car, you may just have to take short breaks between sections to let the compressor catch up.

scooter

iTrader: (11)

Forget about the tank size, it's all about the CFM of the pump. Get the largest motor and pump you can afford(CFM). As long as the CFM is higher than your tool it will keep up with your demand. Any quality pump and motor should be 100% duty cycle.

I have a 5HP Ingersol Rand compressor that I got from Tractor Supply when I bought my house 10 years ago. It's rated for 100% duty cycle, 135 PSI single stage and I want to say a 35 gallon tank. I use it for all kinds of tools, but the most demanding is my blasting cabinet. It is able to keep up with demand while filling the tank at the same time. The tank is only there to supply short term air without the compressor running and prevent pressure spikes. Many of the screw type compressors have very small tanks because they make so much air.

Also, put as much mass as you can into the air system unless you have a real drier. I have a little over 15 feet of black pipe after the compressor and before the water separator and filter. After extended uses there will be much water collected in the black pipe. The mass of the cooler pipe helps the water precipitate out of the hot compressed air. Water separators and filters can only do so much about getting the water out of the air.

jharrison5

So years ago I bought a 6hp 33 gallon Craftsman compressor that served me very well until I got into blasting and painting. The main issue I had was that while the compressor was working so hard it built up too much heat sending a ton of water into the lines clogging up my blast gun and messed up my paint. Once I moved into my current home I spent the money and bought an 80 gallon 5hp single stage setup from Menards on sale for $650 shipped. I then added $250 worth of filters, air lines, and after coolers to make it super dry. I haven't had a single issue since upgrading.

What I learned in the process was that I really didn't need the 80 gallon compressor all I needed was $250 in filters and after cooler system to pull the water out...

vinny R

I have over 30' of pvc pipe snaked back and forth under my work bench to cool the air before it drops down into 2 filter separators. A powered cooling unit works best but either way it is a must to keep the moisture out of the air or as you know that will ruin any paint job regardless of compressor size.

jharrison5

If you're short on space I found that plumbing and sandwiching A/C condensers together with a fan running through them will cool the air down real quick. I ended up using a transmission cooler and separator in-between the pump and the tank and it worked out great. Very little condensation in the tank and then added another separator down line for the blast cabinet and painting.

scooter

iTrader: (11)

That's a great idea. Do you have a part number or make for that trans cooler?

Billgluckman

Idk if you got a gun yet or not but Eastwood claims this one requires only 4.5 cfm at 30psi. I’m not sure how true that is but if I was worried about my compressor I’d try it.

https://www.eastwood.com/concours-lt...3mm-51275.html

Abubaca

iTrader: (3)

Thanks for all the replies! ...as for the cooling...I've read a lot about this too. Compressor constantly running means more hot air, condensations, all that mess. Was curious about real world experiences, and I appreciate you guys sharing your experiences.

....as for the gun, I've seen that gun too. I've watched/read lots of good info on their higher end CC500 gun, but that requires more air than the one you've listed. ....we'll see....I've got time. I'm just researching at this point.

jharrison5

Yup it's a

Abubaca

iTrader: (3)

JHarrison, that's a great idea btw. I like it.

jharrison5

Thanks I stole it off of a YouTube video. I have also seen guys use old A/C condensers from the junk yard, but I wanted to make sure it didn't leak, so I bought new.

On my setup the tube coming out of the pump is 200+ degrees and by the time it hits the filter it's 85. If you're going to run a setup like mine you have to put a separator between the cooler and the tank or it will just pump the condensation into the tank. My separator empties automatically each time the compressor shuts off and the bleeds out.

Hawkeye1980

iTrader: (3)

I went out and bought a 60 gal one from Lowes. Its so nice to run all sorts of tools on it.