migging SS with inverter ?

Sad day, I just ran out of my spool of Avesta 308LT0-1 dual shield wire and just priced a new roll. Ouch. Is there any way to get similar results with solid wire. I have tried before with a lincoln 175 but was never happy. I now have an LN25 with Powcon400sm and would like some starting perameters, like voltage and wire speed Using .035 308l wire and welding 1/4 inch and 3/8 inch plate. There is also a puddle control and a choice of short arc or spray. I was using the spray mode with the dual shield but didn't seem to work with solid wire and short arcing seemed like too much splatter and high bead.I normally tig weld but some bigger projects are just better migged but rhey need to look good.That avesta wire lays down nice but price has gone up. I wouldn't mind finding a better source for this or some other dual shield if I can't get results with solid wire. Thanks for any help
Jim

What gas are you using to mig the SS? When I got my Miller 200 the company had a gas that would work with steel or SS. It is a mix of 49% argon, 49% helium, 2% O2. They told me pure argon migging SS would pill the weld on top of the sheet. I should memtion I am NOT a great SS welder. This just what I was told when I bought my Miller.

Kent

I have a small bottle of Trimix but it has never worked noticibly different than standard 75/25 mig gas for steel. the 75/25 is reccomended for the dual shield also.I think different gas companys mix trimix differently. That mix you have does not sound familiar but I think there is a better mix than what I have and I think I need an even different gas to get it to work in the spray mode. It amazes me that different gas mixes make so much difference with mig. Tig is so simple, just one gas for everything. Maybe someone has some gas reccomendations.
Thanks Jim

Jim,

I think there is a trimix that is ONLY for mig welding of SS. The company I bought my Miller from came up with this trimix to be dual purpose to maybe reduce, I think, the number of bottles need. This gas mix, steel and me did not get along. I was always burning up contact tubes. I mostly use pure CO2. I tried 75/25 for some heavier welding. I could see little differance from CO2. Again I do not claim to be th bet welder around. I may be better than some but I am not good enough to hand tig wire to the best.


Kent

I've used straight CO2 as well, with Avesta 316L fluxcore wire. I've not come across a hard wire that goes down as nicely - the few I've used (with tri-mix) are pretty spattery and lumpy, unless it's just the operator... Anyway, if it needs to look good, I'd say stick with the dual shield - it's easy, looks great, and you're already familiar with it. Of course, it's easy to say that when you're not the one footing the bill! What's it going for these days, anyway?

Andrew

There's a lot of information around that says the Trimix gases are nothing but an overpriced sales gimmick cooked up by gas suppliers. In running trimix versus 75/25 on SS sheet, I'd say the info is pretty accurate. If anything, I thought things went better with 75/25. For heavier stuff like 1/4 or 3/8, spray transfer is the way to go for speed, appearance, and penetration. The arc voltage has to be above a certain value for spray transfer to occur. IIRC, that voltage is dependent on the gas, and not all gases will allow spray transfer to ever happen. Seems like the voltage has to be up around 30, but past that I dont remember specifics. Your supplier should have info on what gases to use and starting points for voltage and wire speed for spray welding. When its set up right, a spray weld looks a lot like a perfect bead laid down by a 7024 drag rod.

You usualy need at least 85% of argon for real spray transfer.

I think if you like a type of wire. Stick to it, even if its more expensive. You'll save on time and you'll be happier with the results.

Thanks for the feedback on the trimix, thought it might be a bum bottle and I did go down to the supplier and was told everybodys trimix is the same (90% helium,7.5%argon,7.5%CO2)and for spray(90%argon,10%CO2 or 92% and 8%)but the spray gas is only avaliable in large bottles. Kinda like to try spray based on experiance I have had spraying aluminum.Sure would like to find an online source for the Avesta wire, The local Airgas does stock the dual shield in 25# spools at $18. per pound and I have ordered 5# spools from them before at $12. a pound a couple years ago, thought the big spools would be cheaper but I guess everything goes up.
Thanks Jim