shopping for a garage air compressor

[Lothlorian]

I am not all that knowledgeable about air compressors so please help me. I have a little 100 psi which works great for filling tires, shooting staples and small brad nails.

I am thinking of trying some sand and sodium bicarb blasting. What would me a good size for an air compressor for those types of tasks? I would also like to try my hand at spray painting. I don't want to get one that is more then I need, or one that is not sufficient for spraying, or blasting.


Brian

[perryg114]

You will need something big for that. I expect something 2HP or bigger. You want a 2 stage belt driven cast iron compressor with a separate motor. The permanant lube things are not going to hold up in the long run and the CFM per W of power is not as good as a two stage compressor. They also wear out with heavy duty use.

Perry

[Nuvite-F]

Sand blasting takes a lot of air. If you are going to do much of it I would recommend a 5 HP 2-stage compressor. Once upon a time that was a commercial grade compressor but it seems like costs keep coming down.

A 5 HP compressor will require 240 V. Do buy a 2-stage compressor; they are more efficient than a single stage, i.e. more compressed air for a given amount of electric power.
.

[Lothlorian]

Thanks guys


Brian

[clancy_boy]

Sand blasting and paint spray demand a constant flow of air at a set pressure - therefore volume is what you should look at. Larger tanks are a good thing - keeps the cycle rate on the compressor down. This limits portability but you said you wanted a shop compressor. I would look for a 240V system - thy use power more efficiently and should last longer.

[ck21084]

I was able to pick up a 80 gallon at lowes for $350. This model should do what you need.

[Steve Bryant]

I have a 5 HP 2 Stage Ingersol Rand that I bought about two years ago from Sears of all places. They were running a compressor sale and it was discounted about 25% and they had free shipping to the store. I did have to run a new 220V single phase circuit (but I have a branch circuit breaker box in the garage) and I installed permanant piping with two quick disconnects. I can plug in my regulator/water separator directly into a wall-mounted quick disconnect or run an extension 50 foot 1/2" inside diameter hose to the quick disconnect and then the regulator and another 50 foot 3/8" ID hose. With this I can go to the end of my driveway, inside my house, etc.

For information on tools and garages, I can recommend the Garage Journal Forum as a good source of information. Another good resource on tools and fabrication is the LS1Tech Tools and Fabrication Sub-forum.

[AIR-Quarius]

I do sandblasting and airbrush. Make SURE you DO NOT get an oilless compressor. The parts are made out of teflon (like the diaphram) and when it breaks down - and it will from running so much, -the kit to repair it will cost you a fortune.
Get a compressor that you would put oil in. If you are blasting art onto glass- please DO cover your nose, mouth and eyes, as the silicate glass that flies away as you blast can get into your lungs and kidneys.
Get you an airbrush and have fun instead. I would stay far away from sand blasting.

[Friday]

Media blasting is a high-volume process... big tank if you are going to run a lot. I used to do blasting with a small 2hp 5 gallon compressor. Worked OK for small jobs or if you could wait 1 minute after every 10-15 seconds of blasting.

There aren't any magical brands... the technology is pretty old. Get something cheap with local service/warranty available. If you get too huge a tank, but only do odd jobs, you'll be forever waiting for it to pressure up when needed. Sometimes a high-volume compressor and a small(er) tank can do just fine.

[AIR-Quarius]

You want a pretty good sized-not huge compressor, especially situated to mount in your truck. This way you have your compressor 'on the go!' ha - I have a five gallon one like Friday said he used to work with. I keep it mounted to the tool box sideways. With three sections of rubber air hose that go 150 feet out. With my airbrush- it has a six foot smallish hose that connects to the larger airhose, and where it connects is a gold hook that I hook into my belt loop. That keeps me from tripping over or handling the hose and just the airbrush is what both hands are on. When you airbrush you should learn to stand with both feet planted - arms, steady at your side and holding your airgun with BOTH hands.(like a praying mantis pose) anyway if any of you want to know something about airbrushing with a double action air-gun. I am not plugging myself here either...I just wanted you to see some of my accomplishments with an airbrush, I'll find a link here...no - better yet I will post one of my favorite pictures of me painting.

[Aerowood]

I've had a 5hp, 2 stage, 60 Gal tank compersser for many years now and have almost always never run out of air. Large area madia blasting is what kills it the fastest. I plumbed the whole basement, garage and have exterior outlets as well. One of my issues is dragging 2 hundred feet of air hose around. My wife drew the line on air taps in the living area though. I even have a tap into my sprinkler system so I only have to open a valve to do my winter sprinkler blow out. My Manifold system is soldered 1/2" copper pipe. I installed it when copper was still reasonable priced.

[Lothlorian]

Here is what I want to do with the job I have in mind. I want to use sodium bicarbonate and blast the belly pan of my 1960. I posted earlier and was informed it will dull the underbelly finish. I really don't care because the underbelly is not where people are going to look. I also want to blast the tubes where you keep the hose for the dump valve. They are dark brown in color. Plus I have some metal wrought irong furniture and just bits and pieces of metal I want to blast.

My little compressor works great for little jobs but I have for a couple of years wanted to upgrade to one that can be used for most everything. You guys have given much to think about.

If I don't buy a compressor I want to find somebody who does sodium bicarb blasting to do the underbelly of my 1960. 52 years of oxidation underneath and I really don't feel like spending hours with a dewalt polisher on my back. I have used the dewalt polisher on the top and sides of the trailer and it was some serious work. I have two more polishes to go.

Brian

Thanks

Brian

[ROBERT CROSS]

Just what worked for me....

When I retired I had all these air-tools that were useless when I wanted to do the auto/Airstream stuff at home.

Craftsman #919.167780, 145-175psi, 25gal, 2 stage, Twin V, portable.

Although it's a 120v 15a unit it's worked without problems for 8yrs now.
Seen some hard use over the years, but keeping the tank drained when not in use and a good line dryer has kept my tools in good shape and the tank rust free.

If its not a constant use compressor, day in day out.... I don't see why a similar unit couldn't work for you.

Bob

[Aerowood]

Many years ago I restored a 59 Willys wagon and sand blasted it. I own a pressure pot type sand blaster. I got tired of waiting for my compressor to keep up, so for this job I went to the local retail yard and rented their smallest diesel powered screw compressor. That made short order of blasting the Willy's and was well worth the cost. For most small media blasting jobs a compressor like those listed above are more then suitable for the task. So what I'm trying to say here is to buy a compressor that is large enough for the biggest percentage of your jobs but rent for those very few times that you really need huge amounts for CFM.