Mig Cylinder Tank Question(s)

[Alphlulu]

Good Morning:

Well, I finally broke down and bought my wife that MM210 unit she has been dying for, (with the spool gun option so she doesnt think that I am being cheap). The unit should be here in about 1 week or so.

My immediate question concerns the cylinder tanks. First, I have 2 older CO2 tanks that I used to use early on for pressurizing draft beer kegs for parties, personal use, etc. I beleive that both are old, ie, > 10 years, and are out of the certification range, hence not sure if they could be refilled. Do any of you guys know what it costs/is it worth it to have the tanks re "hydrotested/certified" (I think thats the right term). I believe they are 20 pound tanks.

Second, I have learned (much through this message board) that Argon, both straight for aluminum, and as a mix for steel is a good idea for a better quality weld. If I had 2 different tanks, would it make better (more economical, etc) to fill one with Argon, the other CO2 and connect both tanks to a regulator to mix the gas going to the gun to a 75/25 ratio for steel (and does this require a special regulator) and then have the fleibility to weld aluminum with just the argon tank, or should I have one tank filled with the premixed (I think this is the right term) 75/25 that they sell, and the other filled with straight argon?

Thanks - Ron - San Jose, California

[cope]

You can mix your own but it is an expensive set up. I would get a C-25 and a straight Argon and use each for its intended purpose.

[Roger]

You can probably take your CO2 tanks to gas suppy and they will exchange them for full tanks. Less than $20 should cover hydro if you want to keep bottles.

[MAC702]

If you have a CO2 regulator, try the CO2 before swapping to an argon mix. You'd be impressed at just how well it does. I traded my CO2 for an argon mix and it wasn't worth it except for the easier ability to do the thinner stuff. I should have kept the CO2 and just bought an argon mix outright. It will last longer and be cheaper to fill, too.

Other than that, I second the idea to keep different gases on hand rather than try to mix them yourself, especially when a machine has separate hookups for the spoolgun gas.