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Hellbender
04-26-2003, 09:55 AM
Is there any kind of a guide for adjusting shielding gas flow on a MIG?

I have a flow guage (little floating ball), use CO/ARGON mix, and I just put the little ball in the middle of the range for indoor welding and give it a little more when the wind is blowing for outdoor welding. Never change it for different welding temps/etc.

I didn't get a book with my welder and I was wondering if this may be part of the problem when I get a poor weld I can't figure out.

I was raised with an old Lincoln stick welder and this new fangled stuff takes a little more brains (which are in short supply at my house).

Thanks,
HB


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NRA Lifetime Member

jfsmith
04-26-2003, 10:47 AM
My MIG came with a pre set regulator, but you may want to call you local welding supply house for that info.

Jerry

Michael Az
04-26-2003, 10:55 AM
My Miller came with gauges for the bottle and it I run 20 to 22 lbs.
Michael

Kerry.S
04-26-2003, 11:40 AM
the amount of shielding gas flow is based on the quality of the weld you want or the type and area you are welding in. any where between 15 and 30 CFM is fine. and more is not better. if you have too much flow you will blow the arc path around creating a crapy weld if to little gas is used well you know we've all tried to weld with the mig at least once withthe gas off welds like crap full of perosity. It's not all that critical though.
Get your self a copt of the Lincoln Electric procedure book of arc welding.
it's like the machiners hand book for welders.
Kerry

lynnl
04-26-2003, 11:45 AM
I too just have the pre-set regulator, but want to get a flowmeter. I can't quote any scripture or verse, but I've been led to believe that gas flow should be varied along with power settings and wirefeed rate, for optimum welds. Now, as to what flow rates should accompany the other settings...? I don't have a clue. Sorry.
...but now that I think of it, I'm pretty sure I have seen written data relating to this. Can't remember where tho.

I'd kinda think it quite likely sometimes incorrect shielding conditions could cause weld quality probs that would not be apparent to the eye, e.g. hydrogen embrittlement. But I'm only guessing.

jfsmith
04-26-2003, 02:45 PM
I checked it is in my Lincoln welders guides. Many tables for several combinations of gases and feeds, verses materials.

My preset works well for me, so for now, I will use it as it came.

Plus I use C02 with my flux core stuff, it works well.

Jerry

BC21OSH
04-26-2003, 03:23 PM
HB,

Just reading through a new book I purchased. It is HP Books - 1264 Welders Handbook by Richard Finch. He says settings vary from one machine to the other, even though they are the same model. Variables to consider are how fast the wire feeds, how hot the wire gets and how much shielding gas is actually supplied when adjusted to 20cfh.

He suggests setting the machine and then making practice runs on material you are planning to work with. Keep adjusting until you are satisfied with the results and then record them for future reference. He suggests you have someone monitor the gauges while you are welding and then record those readings.

There is a chart but it is a page and a half for all types of materials, gas combinations, wire speed, amps, voltage, wire size etc.

Bernard

Joel
04-26-2003, 06:39 PM
To add: A weld on an inside corner takes less flow than a flat weld, and an outside corner takes more. 15 to 30 is about right.

RSFABSVC
04-26-2003, 07:42 PM
GAS FLOW FOR MIG WELDING WITH ARGON\CO2 MIX SHOULD BE SET BY SIZE OF NOZZLE ON THE GUN.
A NOZZLE WITH A 5\8TH OPENING I FIND TO WORK BEST SET AT BETWEEN 30 TO 45 CFM.
SMALLER NOZZLES SUCH AS THE ONES USED ON LIKE THE SMALL LINCOLN SP100 MIG MACHINES SET AT 15CFM.
WHEN WELDING OUTDOORS IN A BREEZE TURNING GAS FLOW UP DOES NOT REALLY WORK JUST TRY TO SHEILD THE WELD AREA FROM WIND AS BEST AS POSSIBLE.
SOME PRE SET REGULATORS WELL HAVE A PLUG OF SOME SORT ON IT THAT CAN BE REMOVED. UNDER PLUG IS USALLY A ALLEN HEAD SCREW WHICH CAN BE TURNED IN OR OUT TO ADJUST FLOW OF GAS .

RICH S.

Thrud
04-26-2003, 11:20 PM
Hellbender:
First of all, clamp the base of the nozzle and insulator to the gun with a screw type hose clamp. This forces the gas to flow out the end of the nozzle where it belongs as there can be considerable gas loss otherwise.

Then adjust the gas up until your weld no longer has any porosity. Once set you should never have to re-adjust it. Make sure you use a spatter release gel to dip the nozzle (while hot) into after scraping any spater out of the nozzle. Your welds will be beautiful.

SJorgensen
04-27-2003, 03:39 AM
If you think about what you are trying to do with the shielding gas, you will answer your own question. The effect that you are trying to accomplish is to be sure that your weld not is not in an oxydizing environment. It seems to me that controlling the environment over the weld is the primary thing. Draping fireproof materials, preventing drafts, creating a puddle of heavy shielding gas should be the idea. If you can just blast shielding gas over the weld I guess that is fine. I used to know an expert in underwater welding that I would have loved to ask this question.
An interesting sideline. He told me that he had shot several films with Jacques Cousteau. He said to me that he had personally pushed shark carcasses toward the camera for those films.
Another Illusion of reality is lost for me. Yet Jacque Cousteau showed us all a world that we didn't know existed.
Spence
He was a pretty tough guy and I'm not sure if the sharks he pushed into the camera were dead or not. I just assumed.
Spence

[This message has been edited by SJorgensen (edited 04-27-2003).]