Supermechanic,
What's the point of mixing your own gas?
I'm afraid to recommend it because I have no faith in my ability to reproduce the mix with sufficient precision; I also find the additional tank of gas is cheaper than a decent flowmeter... <80%Ar (balance CO2) lets me weld anything made of carbon steel in short arc or spray... I presume AR100 would permit me to weld Al- unless I wanted or needed to improve the characteristics...
...do you actually use (can you accurately mix) your own mix for stainless without complications from the CO2?
Two flow meters cost about $200, hoses and fittings are additional; you can pay that or more for a single one that's accurate I suppose, while THREE tanks of the OPTIMUM gas mixes for each metal application should cost about $80 each. Aluminum, Stainless, and Steel, respectively, behaving exactly the same each time you strike an arc on one of them so you can depend on the quality of the weld.
Your rationale is usually right on target, S, but I think I am missing your point or something here.
My weld supply shop is less than 5 minutes away, and the guy's able to provide the precise mix I'd prefer to use. Maybe this convenience has me thinking differently, but we're sharing different opinions with each other on this issue; I considered and rejected the idea quite some time ago.
Regards,
d
You cant buy a better spool gun than the miller 30a.aluminum must be welded with 100% argon,which wont work well with steel,although it works with stainless.use a gas mix with steel.switching from steel to al and back is no problem,usually you would need a different size of contact tip anyway.for aluminum i only use .047 5356 alloy wire spools. A regular wire feed usually has a much larger spool, mine takes 50lbs.you dont have to change the wire often,the gun is lighter and easier to handel but you are limited by the length,usually 15',although possible they dont work well at all with aluminum