Regulator, Flowmeter LPM Setup

[BigBunny]

Hello Folks,

I am new to MIG welding, so please forgive me if these are basic questions.

I have just brought a new welder (Clarke 135TE) and have just finished the bottle of CO2 gas that came with it. I calculated that it would be more cost effective to use a rent free gas bottle and opted for a Argon 93%, CO2 5%, O2 2% mix. I will be welding mild steel, 1.6mm box tubing.

I have fitted the regulator, please see attached photo, this includes a flowmeter on the regulator and a separate (more accurate or so I believe) flowmeter.

When I open the Regulator value in order to maintain a flow reading on the Flowmeter of 10 LPM (when the trigger of the MIG welder is pulled) indicated by the yellow tape. As you can see from my photograph I then have a reading on the Regulator Flowmeter of 20LPM. Would you expect to see this ? (I should say that at this point the valve on the tubular Flowmeter itself is open fully). But the ball floats at 10LPM.

I can hear the gas flowing out of the gun. It does sound a lot, lot louder than when I was using the small disposable bottle of CO2 gas.

Is this to be expected ? Or is the fact that I have, in effect, two flow meters causing me problems ?

The second photograph shows a practice weld. I am getting a brown deposit (soot for want of a better description) on my weld bead. This was not something I was getting with the disposable gas CO2 cylinder.

I have switched from using CO2 to using mixed gas. Is the brown deposit as a result of the new gas, or is my gas flow too low.

The bead also looks dull, with a little wire brush it still looks dull, again compared to a weld done with C02. Again, is the a characteristic of argon mix shielding gas ?

I am concerned that if I crank up the gas flow any higher I will cause turbulence and in effect pull in air into the weld, rather than having a laminar flow of shielding gas. And I will be wasting gas. I started today with 200bar on the cylinder.

Out of curiosity, what flow rate do you get from the small disposable gas bottles ? Mine just has a scale 1 – 6 on the regulator (Machine Mart, UK).

Thanks for your help and advice
Much appreciated.
Simon

 

[wyn]

I would just go off the second flow meter.....but it needs to be vertical.

Turn the regulator so the dials are facing up then turn the flowmeter so it sits straight up.

 

[Bill Edwards]

^^
Ignore the dial flowmeter and rely on the pea shooter type when it's fully vertical.
Don't worry about the brown deposits on the weld, that's fine. You'll probably find the proper gas mix to be far better to use than the CO2.
As to the flow rate with the disposable bottles - it depends. They aren't very precise pieces of kit.
You may be fine to knock your gas flow down to about 8 if you want.

 

[Robotstar5]

Turn the regulator to a higher flow rate than you need then adjust the flow on the flowmeter with the black knob on the side.