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Up Topic Welding Industry / General Welding Discussion / CFM needed for arc gouging
- - By Robert48 (**) Date 12-10-2010 01:46
I have a large engine driven compressor that I sometimes use for gouging. I think it is around 26 cfm. I have never run short on air while using 5/16 carbons. The problem is it's too big to keep on my truck all the time, and as you all know when you don't have it is when you need it. I was thinking of buying one of those twin tank models with the Honda engines around 14cfm because I could mount it on the truck without loosing all my space. I see alot of these on welding trucks but don't know if people use the for gouging. I know someone here can answer my question.
Parent - - By J Hall (***) Date 12-10-2010 03:59
I run 21cfm and it is ok for 1/4 but a little short for the bigger carbons.
Parent - - By Robert48 (**) Date 12-10-2010 12:58
So I guess I need to keep the big one then.
Parent - - By TozziWelding (**) Date 12-10-2010 23:47
How many CFM for carbon arc, the more the better.
Parent - - By Tommyjoking (****) Date 12-11-2010 02:28
I run one of those little twin tank jobs the carpenters use for squids, air chisels etc. and it was perfect for that.  I think on an arc gouger it would begin to wheeze and get asthmatic quick like.  Maybe you just need to go for broke and get an Airpac...not.

just a from the hip $.02
Parent - By scrappywelds (***) Date 12-11-2010 04:45
i feel lucky plant air where i work is 200 psi run on a 1" line, with a 500 amp machine used only for gouging.
Parent - - By Robert48 (**) Date 12-11-2010 22:59
That's probably not going to work for me. I need one that will handle carbon after carbon sometimes. I guess i'll keep luging it on and off the truck as needed.
Parent - - By Tommyjoking (****) Date 12-12-2010 07:10
well sorry.....manly gouging takes a lot of air.   Did you ever get that 300d straightened out?
Parent - By Robert48 (**) Date 12-12-2010 13:58
Yeah I did. Sorry I didn't update that post. I run it without the lead reels and it is alot more consistant an smooth. I am keeping the reels on just because of the convenience for work that is not that critical. But at least i know how to fix it when I need to.
Parent - - By welderbrent (*****) Date 12-15-2010 23:27
This question has come up before.  May be hard to find under the 'Search' function unless worded right.  I didn't try either so I don't know.

Anyway, I have done a lot of air arc with smaller compressors.  12-15 cfm will work but will work the compressor full time.  The bigger the compressor and the more tank you have the longer it will last and more efficiently it will work. 

Most work can be accomplished without opening the air all the way on the torch.  It still requires an awful lot of air to run it good, fast and clean.

I also find most of my work can be run at about 60-80 lbs of pressure.  It doesn't require full time 150 lbs plus to get the job done.

While it most definitely depends upon the exact material, thickness, and application  I find many people run too large of an electrode and too much amperage for the job they are doing.  They also run way more air than they really need. 

Just my two tin pennies worth.

Have a Great Day,  Brent
Parent - By Sberry (***) Date 12-16-2010 01:42
Yes, agreed, you can do it with smaller comp by turning the air down and being operator thrifty too, I have thumb right on the button, any time I not arcing the air is off giving it a chance to recover.
Parent - - By Cumminsguy71 (*****) Date 12-18-2010 21:33
Have you checked into the rotary screw compressors? A friend of mine works at a place and they have one on their service truck. He said it is one bad azz compressor. All the service trucks at the Cat dealer I used to work at had them. Darn things are supposed to last forever and push some serious air. Here's one place I found in a search,

Here's something else, underhood compressor, 70cfm, not sure what would be available for your rig,

....and another.....
Parent - By Wrench Tech (**) Date 12-19-2010 00:42
I run a VMAC on my truck and it is an awsome little unit - 75 cfm and only a little bigger than the alternator.  But I use some bigger air tools which use a lot of air - maybe even more than air arc though perfect for that, too.
Two disadvantages - killer expensive - more than $5000 for the kit for your truck.  And you gotta run the truck engine and the welder to air arc.  Sure, it gets the job done but all those sparks and noise aren't for free.
I kinda need it but you'd need to do a lot of goughin' to make that pay.  If you're just welding ( or goughing) the airpack thing is a better configuration.
Oh, and they don't last forever - had to replace the compressor part of the kit once already.
Parent - - By Robert48 (**) Date 12-21-2010 02:09
They are not all they are made out to be. We have a very large IR screwdrive in our shop. It is only 17 cfm and like I said is very big. The engine drive on my truck is 25 cfm. We have had alot of problems out of ours from not using it enough. The IR repair man said they are made to run at almost 100% duty. That is the advantage over a piston type. They also produce very dry air so they are good for plasma and painting. But that is a shop unit I don't know about the truck mounted models.
Parent - - By Cumminsguy71 (*****) Date 12-21-2010 11:59
I think my buddy said it runs all the time or something, not even sure if it had a tank on it or if it just pushed enough air without storing it. I didn't see a tank up top on the truck anywhere, it's been over a year since I saw the truck.
Parent - By DaveBoyer (*****) Date 12-22-2010 01:41
Screw and vane type compressors can be run without a tank [if a large enough compressor is used]. The intake air is regulated to maintain nearly constant output pressure.
Parent - - By DaveBoyer (*****) Date 12-22-2010 01:47
Sounds like Your shop compressor has a refrigerated dryer attached, they provide very dry air, but add another level of complexity, bulk and power consumption.

The actual screw compressor pump itself is pretty small for it's output compaired to a piston type compressor.
Parent - - By Robert48 (**) Date 12-22-2010 02:30
It does have a dryer and I think it's an 80 gallon tank. The IR repairman said they sold us the wrong compressor. He explained how those are for almost constant use (auto body etc) There are times that ours does not turn on for a week.
Parent - By DaveBoyer (*****) Date 12-23-2010 03:52
Yes, that is a large investment for ocasional use. The places I worked were serious air users. (2) of the shops I worked in upgraded to screw compressors, one for efficiency's sake, and the other due to the need for greater capacity.
Up Topic Welding Industry / General Welding Discussion / CFM needed for arc gouging

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