Newbie, with question...

[mh434]

Hi, folks, I'm glad to be here!

Quick couple of questions -

a) I've recently moved up to a Miller 190 & Spoolmate 100. I plan on doing some aluminum welding, so have acquired a small bottle of argon for the latter, in addition to the large bottle of 75/25 Ar/CO2 for steel welding.

Now, I have one, single job I need to do on a stainless marine dinghy bracket (crack repair), and I have a 4" spool of .023" stainless MIG wire (don't recall the alloy specifically, although it was supposedly the correct one for the bracket I need to weld). Unfortunately, the cost of gas bottles hereabouts has soared over the past few years. The used, beater 2' bottle of argon I just bought for aluminum welding was $350 (refillable for the cost of the gas alone, in future), but a bottle of tri-mix for stainless is over $700...a little (okay, a LOT) beyond my budget now.

My question is...would it be better to take a stab at this repair using 1) straight argon, 2) the 75/25, or 3) don't bother trying?

On a related topic,

b) It's not a big hassle switching the regulator from my 75/25 bottle over to my argon bottle for spoolgun use, but IF I was able to acquire a second gas regulator, what do you think of the idea of putting a Tee into the gas line into the welder, and run the second line to the alternate bottle & regulator (both bottles are on the same cart)? My thinking was that, if I simply turned off the regulator on the bottle I wasn't using, and turned on the other one, after a couple of seconds of purge, I'd be onto the appropriate gas without moving the single regulator from one bottle to another...

Your thoughts?

Thanks, folks!

[MMW]

While not the best 75/25 will work. It will reduce the corrosion resistance slightly. Over the years many stainless things have been welded with 75/25 & the world did not end. Is it perfect, correct? No but it will hold together. Whether you do the job or not that is up you.

I don't have an answer for you on the second question but the reg on the closed bottle will have pressure pushing on the diaphragm from the wrong direction. Will it matter? I don't know.

[mh434]

Hmmm - I hadn't thought about the diaphragm issue. Maybe a non-return valve in each line...guess maybe I'm over-thinking it!

Thanks for the info on the stainless/75/25 welding! There's nothing to stop me dabbing a little clear on over the weld to try to reduce corrosion once it's cold, and it sure beats spending $700+ on a tank of gas for a single weld...

[Broccoli1]

Put quick connects on the machine and hoses.

[Ironken]

I agree with Broccoli or if I recall correctly, Western makes a Y connector with valves on two of the legs of the Y or they also make inert quick connectors.

http://www.amazon.com/Inert-Valve-Argon-Western-411/dp/B008BJG4KC

[mh434]

Excellent suggestion! Thanks, folks!

[ryanjones2150]

I have a medusa look to my wall of gas cylinders. Hoses and valves and gauges everywhere. Those western Ys with the valves work really well. I also have check valves in line. If you use check valves, make sure you check your gas flow at the nozzle to get an accurate read, if that's important to ya. For me, the check valves changed the gas output slightly. I would absolutely recommend the check valves. It only takes one little whoops to contaminate your gases. And $700 for a bottle of tri-mix? Holy smokes. I don't think I paid near that much for mine. And unless you're doing a good amount of stainless welding, you're fine with the steel mix. Probably have some soot to brush off. If you are getting into welding stainless, consider the TIG process. But also...we must not forget the hexavalent chromium...wear a respirator that filters that stuff.

[xryan]

$350 for a 40cuft bottle? Holy $#@! Where are you located? The moon?

[mh434]

Nope - Canada (west coast)...prices have more than doubled in the past few years!