View Full Version : millermatic 251 shielding tanks
I had purchased a Millermatic 251 a couple of months ago and am just now about to purchase the shielding tanks for it. I do occasional welding of both steel and aluminum and wish to have both tanks. I am wondering what size tanks I should invest in. My supplier will sell tanks of 125 cu ft and less. I have also known people who have run theirs with 75 cu ft tanks. I would prefer to keep the tanks small, but wish to have an adequate supply for the occasional medium size jobs. I don't think I want to get into renting the tanks for the simple fact that in two or three years, I would have already paid for the tank.
Since I'm sure many have had more experience with these things than me, I'd really appreciate your input.
Thanks for any help.
Long term rental of the cylinders makes no sense to me too. As far as tank size I would start with an 80 cu. ft. for steel this would give you about 4 hours of weld time from a tank of gas. For aluminum I would probably go to a larger tank , because you run almost twice the gas flow on aluminum.
Also, if the 80 cu ft doesn t workout most welding supply stores will allow you to trade up to a larger bottle and just pay the difference in cost between the two bottles. For me though the 80 cu ft works out fine. For one thing it is only about $30 for a refill. By the way Im using this size of bottle on a MM 210.
Also, Im assuming that for steel your looking at a bottle of 75% argon/ 25% CO2 and for aluminum 100% Argon.
Now Im going to open up a whole different can of worms. If I had a MM 251 along with a bottle 75/25 for steel I would also have a bottle 98% argon / 2% oxygen for doing spray transfer on thicker material.
Thanks for the great advice. It's good to know that some of the welding suppliers will let you trade the tanks if you need larger. It's also reassuring that you have the mm210 and are using that size of a tank. I'm sure that you must do quite a bit more welding than I would be doing at any given point. I would have liked to have had only two shielding gas tanks, but I will be doing steel, stainless steel and aluminum at times, is there any gas mixture that covers two of these metals? I was thinking that I could use the aluminum spoolgun to weld stainless, so I would not need to feed it throught the whole mig gun each time. Tell me what you think.
To add a little more the estimated 4 hours of weld time that a 80 cu ft bottle will allow it actually quite a lengthy time period for normal home welding.
If you want the optimum performance from the process on each metal then 3 seperate bottles of gas is the minimum way that your going to have to go.
The spool gun is by no means just for aluminum. A large spool of stainless steel wire can be quite expensive. A 10 lb roll will be around $120. where as a 2 lb spool will be around $25. Obviously, in the long run the 10 lbs spool is cheaper. But sometimes it is easier to come up with the $25 then the $120+. When some people change rolls of wire on the machine they take the time to roll the wire in the gun cable back onto the spool. I don t do this for steel wire, but I would definately do it for the price of stainless wire.