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Air Compressors

Posted: Fri Jun 26, 2009 12:43 pm
by DeCalmont
So, I got about $250.00 I can spend on an air compressor. Besides the usual things (inflate tires, toys, etc...) I was thinking maybe something like a nibbler, cut off wheel, grinder as possible useful tools as well. What kind of CFM/Psi should I be looking for? I'm assuming the bigger the tank is would be better as well. Any help would be greatly appreciated.

Posted: Fri Jun 26, 2009 1:15 pm
by schreiber
I haven't seen an air nibbler which is rated for armor thickness steel... only duct thickness.

In my compressor experience (which doesn't have to do with armoring) the size of tank and power of the compressor mainly control how much you're going to be listening to the compressor. They are darned noisy, and if you're in an enclosed space it'll be pretty annoying. Bigger motor means less time running, bigger tank means less frequency running.

Personally, if I got one I'd stick with the automotive uses - I'd definitely see about getting an impact wrench for lug nuts. The first time you change your own brakes it practically pays for everything.

I'd also look for disc grinding attachments... but that's really the only armoring use.

Which is not entirely true. The main reason I don't have one is because I would very much want to get an air planisher. That's a problem since it requires way too much area/ volume of the shop for a compressor that can do that. Like, a whole workstation's worth of space.

When I get one, it's probably going to be a pancake, it's probably going to live under a table, and it's probably going to be off most of the time. I'll put up with listening to the motor the one time a week I fill the tires.

Posted: Fri Jun 26, 2009 1:20 pm
by DeCalmont
so far the heaviest nibbler I've seen cuts 14g mild/18g stainless

Posted: Fri Jun 26, 2009 1:42 pm
by schreiber
Generally, any tool run at rating regularly is going to be junk in short order.

For $250, plus whatever you were going to spend on the nibbler, I bet you could get a used pancake, and use the rest on aunishear.

Posted: Fri Jun 26, 2009 1:47 pm
by Dauyd
schreiber wrote:
When I get one, it's probably going to be a pancake, it's probably going to live under a table, and it's probably going to be off most of the time. I'll put up with listening to the motor the one time a week I fill the tires.


Forget using an impact wrench if you only have a pancake compressor. They simply don't have the volume.

I think you can get away with a smaller motor- it'll just take longer to get up to pressure.

But you neede a decent size tank if you are going to use any tools that run for any lenght of time. Impact wrenches, nibblers, grinders, etc all simply use too high a volume of air for the tiny tanks to keep up- and the motor simply isn't designed to make up for it.

Pancake compressors are in their element providing short bursts- more like a nail gun.

Posted: Fri Jun 26, 2009 3:13 pm
by Johann ColdIron
Cut off tools, grinders and sandblasters will suck all the air out of a pancake in no time. They are High CFM tools.

I get about a minute of work time for each 5 min of fill time in my 4hp 20 gal comp. Drives me crazy.

I need to get this guy installed and under a canopy [img]http://i128.photobucket.com/albums/p181/JColdIron/Web-comp.jpg[/img] Picked it up from a friend for...$50

Posted: Fri Jun 26, 2009 5:29 pm
by Sean Powell
If you are going to get an air compressor for armoring that means eventually you will want an air-planishing hammer. Harbor Freight sells a cheepie that will get you started and then you will replace the anvil, dies, hammer and eventually frame if you use it extensivly... but it has a good foot switch that would cost you almost as much as the air-planisher system they sell...

When I thought about buying an air-compressor to do this I was looking at an $800 model from Home Depot. There are more cost effective places to get one if you know where to look. I don't remember the specs but I think I was considering something shoulder high with almost 15cfm. Check the ratings on some Air hammers to get a sense of what you need.

Anything less then this is good for air die grinders for pollishing but not much else that I know of for armoring. Die grinders, pneumatic brad nailers and torque wrenches can be run off decent pancace compressors... but it's SO nice to have more air then that. :)

Sean

Posted: Sat Jun 27, 2009 6:05 am
by Hrolfr
One other thing you can do is make an accumulator for a smaller compressor. I built one for my cousin using old 100# size LP gas tanks.

What you are effectively doing is making larger volume storage tanks for your compressor. :wink:

Posted: Sat Jun 27, 2009 4:36 pm
by white mountain armoury
IMHO pancake compressors are good for running low air consumption tools like nail guns.
Die grinders, cut-of wheel tools, drills ect consume alot of air.
Oilless compressors have short lifespans compared to compressors that are oil lubricated.