[bjfox1970]

I was wondering if someone could tell me what the minimun requrements would be needed for an air compressor. I am planning on sand/media blasting the car myself, and painting it as well.
Looking to get by as economically as possible, but do not want to get a unit that won't keep up.

[bjfox1970]

I was wondering if someone could tell me what the minimun requrements would be needed for an air compressor. I am planning on sand/media blasting the car myself, and painting it as well.
Looking to get by as economically as possible, but do not want to get a unit that won't keep up.

[firebird69racer]

nothing less than 5hp,60gal tank, and two stage pump. compare the cfm rating at the same pressure. and get the bigest one you can aford. I like the vertical tanks as they take up less room. and make sure of your avaible electric load.

[dragula81]

I used my ten year old 110 Volt Craftsman 5 hp/25 gal compressor to blast my front subframe and firewall. I was using a cheap Harbor Freight 40lb pressure sandblaster. This small compressor WILL keep up but it is slow going and the compressor WILL RUN CONSTANTLY. Mine NEVER shut off while I was blasting. This isn't particularly good for the compressor and causes it to get hot which makes the tank build up more condensation so you get more water than normal in the sand. You'll need a good water separator. I also use a disposable water seperator at the connection right at the blaster. Check out my website below to see how my frame turned out.

Last weekend, I purchased a 7hp/60gal single stage upright compressor from Home Depot for $399. I WANTED a two-stage but just couldn't justify the costs right now. The cheapest two-stage I found was also at Home Depot and it was $799 (plus tax). I have not used my new compressor yet for sandblasting but intend to this weekend, weather permitting (I will NOT blast in my garage).

Drag

http://webpages.charter.net/dragula7

[Big Mike]

One that requires 220 volts. Anything smaller will run constantly and not keep up with any constant use tools. As with any tool, the bigger and stronger will always be a good investment down the road. Would you rather buy 3 $299 compressors or one $799 compressor and ber done with it?

Big block? Small Block? Nope, It's a Pontiac Engine!

[Judas]

The biggest you can afford. I have a 32 Gal. model that works well with Impacts and such, but the cutoff wheel makes it run constantly. Wont even bother with a blaster.

We ain't pulling no Punches; We aim where the Crunch is

[tripower]

Another important thing here to remember is the CFM rating, especially if you plan on painting yourself. You should try to find a 12 CFM or better compressor if you want to use some of the better paint guns out there. For media and sandblasting, you will should use one of the pressure tanks for help.

[LEGTO]

You need to look for CFM not horsepower. There are units that say 5 hp and only deliver 10 cfm or less. A true 5 hp should deliver around 19 cfm. I suggest at least 15 CFM at 100 psi. The lower the pump rpm the better the unit is and quieter. You will need a 220 volt 1 phase unit. Dont look at electric motor rpm but actual pump speed. I've been in the air compressor business for over 20 years and get calls every week from guys that bought the Sears, home supply etc., cheap high speed compressors that would not do the job.
Sandblasting will require the most air comsumption. The amount of cfm required will be dictated by the air jet diameter of the the blaster. Hope this helps - just my opinion.

[dragula81]

In response to my previous post above, I just used my new Home Depot 7hp/60gal compressor for the first time with that cheap Harbor Freight sandblaster and it worked GREAT!! The only real problem now is that I'm getting a SIGNIFICANT amount of moisture. I drain the compressor a couple of times a day, I have one filter dryer/water separator and I had TWO inline disposable water separators on it, but the sand is still getting too moist. After using it for about 30 minutes, water was literally dripping out around the fitting at the sandblaster .
It keeps stopping up the blaster. This is with about 50' of copper air line run through the ceiling, and a 50' hose going to the blaster and I'm STILL getting WAY too much water. I'm going to add TWO MORE permanent water separators in it to see if that helps. That will give me a total of 3.

Drag

http://webpages.charter.net/dragula7

[61man]

What LEGTO said. CFM is a lot more important than HP. To do a good job you need a good two stage compressor that will deliver a constant 15 cfm at 100 lbs of pressure

http://kurtspontiac.homestead.com/Pre1964Pontiacs.html

[LEGTO]

Water in the airlines is a problem. If you use mechanical filters/moisture traps, mount them as far away from the compressor as possible. The next step is to lower the temperature of the air inside the airlines. For most applications an aircooled aftercooler will remove about 80% of the moisture, but will run around $300 for a 15 cfm compressor.

[bjfox1970]

Thanks for the help! I will be going shopping this weekend!

[bjfox1970]

I found a us general compressor 6.5 hp 60 gal two stage 13 cfm @90. I know LEGTO said at least 15cfm. But could I get by with this unit. Will be doing sandblasting/painting with it. But only occasionally will not be using it all the time.

[pglade]

cheap refrigerated air idea----anyone tried this?---get one of those cheap "college dorm" small refrigerators, cut a hole in each side and run a bunch of coiled copper tubing inside it with drain at the bottom. Never tried it but it seems like w/enough tubing in there you could knock out a lot of water.

[head #96]

What I do for moisture is coil up about 15ft of rubber line in a bucket full of water. The water cools the air in the line, do this before the filter/trap.

Building a fast stock appearing street car.
homepage http://home.mchsi.com/~vroman6

smalles one i have is 25 hp largest 40hp but then i do it for a living. make sure you use a resperator. not one of those cheap paper dust masks.

if you act like an ass. dont be insulted when people ride you

[LEGTO]

< !doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<meta name="GENERATOR" content="Mozilla/4.78 [en] [Win98; U) [Netscape]">
<title>CFM</title>
</head>
<body>
<font face="Comic Sans MS">To help calculate how big of a compressor
you need, I've included a link below to a PDF chart.</font>
<center><a href="http://home.xta.com/compairsys/cfmflowchart.pdf">CFM
FLOW CHART</a></center>
<font face="Comic Sans MS">As an example, look down the left column (size
of orifice) to 3/32", then follow over to the right until your under the
100 psi. (pressure) column and it reads 14.5 CFM. You can relate this to
a sandblaster by</font>

<font face="Comic Sans MS">saying: If you have a 3/32" dia. air jet
at the end of your blaster hose and you want to blast at 100 psi, you will
need a compressor that delivers approximately 14.5 CFM OR MORE to blast
at a continuous basis. To blast at 80 PSI then you need a compressor that
delivers 11.88 CFM or more. It will help conserve air by installing
a regulator before your blaster or other air tool etc. and set to the pressure
that your compressor can handle. Without a regulator, the blaster will
try to use all the pressure your air tank can provide. ( at 150 PSI it
will try to flow 20.8 cfm) As you can see the air pressure will drop quickly
if your compressor only delivers 15 cfm.</font>

<font face="Comic Sans MS">Bottom line, select the air jet (not sand
nozzle) to fit your compressor.</font>

<font face="Comic Sans MS">Hope this has not bored everyone, Just thought
it would help.</font>
</body>
</html>

[speeder]

One guy I once met used an old water heater tank and attach the right fittings to it and had his compressor pump air into it. Gives him enough reserve for most jobs. Just keep the pressure relief valve on heater for safety.

[Johnp]

The problem you’re having with water is normal. Those water separators will only remove water, not vapor. I don't think you are going to have much luck by adding more separators. The air becomes hot when it is compressed so you will need to cool it in some way so the moisture will condense and then the separators will remove it. There are a lot of ways to do it, refrigerated air dryer being the best and most expensive. I like the idea of a bucket of water with tubing coiled in it, the water will provide good heat transfer. Another option may be a large cooler with tubing coiled inside, and filled with water and ice. However you go be sure to locate the separator as far from the air compressor as possible to give the air time to cool.
Good luck and I hope this helps shed some light on the problem.

John