MIG wire

[Snag]

A roll of flux core 309l wire should be arriving in today's mail .
I'll soon know if it will be the solution to my project . I hope it is ,
I'm a much better MIG welder than TIG . I've been practicing on scrap
exhaust pipe , mild steel and a little SS , and it looks better . But
nobody would actually pay for welds that look like mine ... ah well ,
pretty is secondary , strength and corrosion resistance are my primary
concerns .
--
Snag
Let's Go Brandon !

[Bob La Londe]

That sounds interesting.

Will you switch the polarity like regular gasless flux core steel wire?

Or... Will you run dual shield?

I was running gasless flux core one day and the welds were going like
shit. I had specifically said I was running gasless, and one of the
morons I was helping turned on the gas when I wasn't looking. The gas
was blowing away the flux smoke. I spent a stupid amount of time
grinding and re-welding.

I only noticed it later because I have a habit of checking the gas
bottles when I walk by. I gave it a light twist, and it moved.


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[Jim Wilkins]

"Snag" wrote in message news:spcrch$91l$1...@dont-email.me...

------------------

I still don't know why my MIG sheet metal welds suddenly changed from a mess
of blobs to a smooth even flow with the right penetration. I stopped
practicing and did the fender repairs before losing it.

Possibly the change was from using up the more oxidized wire on the outer
layer of the large spool.

[Snag]

That is a possibility . I put a strip of scotchbrite pad - folded so
the wire has to run thru several layers - on the MIG wire before it goes
into the drive wheel assembly . Cleans the wire some I guess .
Bob , I'm going to try it both polarities . I'll start with the
electrode negative like I do with flux core mild steel , if it looks
good I won't try 'trode positive . If not ...
I was going to try it out this afternoon . After listening to my wife
cuss out her sewing machine (65 yrs old , from her granny) several times
this morning I told her it was time for a new one . A 120+ mile round
trip and 400 bucks later ... but that was OK . I needed to resupply the
likker cabinet , and I patronize a store in that same town . Cheaper
than the one just across the county line , enough it pays for my gas !

[Gerry]

On Wed, 15 Dec 2021 10:17:06 -0700, Bob La Londe <no...@none.com99>
wrote:

Just what everyone needs; "helpful" people!

[Richard Smith]

Never used gasless - however read about.

It says, and makes complete sense to me as a metallurgist /
scientist...

Never use shielding gas with gasless.

The system works because the composition of the atmosphere is known
and just the right amount of deoxidisers and denitriders are in the
wire.

As the atmosphere has the same composition across the world, the
result is, when otherwise used right, end up with the right weld
metal.

Surround gasless wire with a shielding gas and you do not get the
right weld metal.

[Jim Wilkins]

"Richard Smith" wrote in message news:lyv8zon...@void.com...

Never use shielding gas with gasless.

----------------------

I bought a used Powermate Tote-Mig that was permanently wired
electrode-negative, similar to this:
https://www.centurytool.net/117_060_PowerMate_70_amp_tote_wire_feed_welder_s/1674.htm

It's a 75A model 117-027 B with a gas inlet and solenoid. There was no
manual and the dealer loaned me a how-to-MIG VCR tape instead.

It was OK with flux-core but not with bare wire and CO2 for auto body, so I
added terminal bolts to swap polarity, then I got some good welds from it
and the night school instructor got great ones in up to 3/16" steel. Since
he had proven that it worked and I'd paid for the supplies I did the rest of
my practicing on the school's Miller.

Why would an older MIG have a gas solenoid but flux-core polarity?

[Jim Wilkins]

"Jim Wilkins" wrote in message news:spfbr8$qtg$1...@dont-email.me...

"Richard Smith" wrote in message news:lyv8zon...@void.com...

Never use shielding gas with gasless.

----------------------

Why would an older MIG have a gas solenoid but flux-core polarity?

----------------------

This appears to be the answer:
https://weldingheadquarters.com/why-use-dual-shield-welding/
"Generally, MIG welding is electrode positive and welders switching to FCAW
will need to ensure that electrode polarity is negative before they start."

https://www.thefabricator.com/thewelder/article/consumables/getting-to-know-flux-cored-wires

[Bob La Londe]

On 12/17/2021 10:27 AM, Jim Wilkins wrote:
> "Jim Wilkins"  wrote in message news:spfbr8$qtg$1...@dont-email.me...
>
> "Richard Smith"  wrote in message news:lyv8zon...@void.com...
>
> Never use shielding gas with gasless.
>
> ----------------------
>
> Why would an older MIG have a gas solenoid but flux-core polarity?
>
>

The Miller 212 (my best machine arguably) is easily switched with lugs
by the wire feed inside the cabinet. Nothing else changes when you swap
the cables. Always fires the associated solenoid when you pull the
trigger on one of the guns. I expect they figured most folks would only
run GMAW, and never FCAW with it, but the capability is there.

I ran FCAW for years because GMAW just didn't work on my steel stinger.
Since I'm not a real welder or even a real fabricator it took me years
before I discovered the problem. The gas diffuser in the stinger had no
holes. (It came that way directly from Miller.) I did have a gas
bottle sitting there, but it went many years without even cracking the
valve.

P.S. I find (maybe its due to grater experience with it) that FCAW is
much easier for out of position welding. Even overhead.

P.P.S. When I posted pictures of the gasless gas diffuser on Miller's
web forums they sent me a whole box of consumables including a couple
proper gas diffusers WITH HOLES.