Welding with flux core wire?

[David_viny]

I have read somewhere that using flux core wire on body panels can cause paint issues. Something to do with the flux leaching out of the weld and effecting the paint. Is this true? I'm thinking of doing some bodywork, mainly rust repair and I have a flux core mig that id like to use. Id rather not rent/buy a gas setup for the mig just to do a few repairs.

Thanks,
-Dave

[robertjra]

I would like to know this too I was going to start my smothing of the fire wall with flux core

[elitecustombody]

I would invest in a MIG welder,I know alot of us are on the budget, but for smaller projects,even Harbor Freight or Ebay MIG welder would be a much better tool,than flux core welder, $300-400 and you're good to go. If you want, I'll sell you my Lincoln ProMig 135 for $250 shipped,it's dusty,but works, I have used it for no more than few months, the wire feed sometimes chews the wire,so I just bought a Hobart. Now that I mention Hobart, you can pick one up at Northern Tool for $460,well that's what I paid,but worth a try.

[DarkoNova]

I know it's different everywhere, but the thing about MIG is where do you get the gas? And how much is it? Yeah you can get the welder and wire for like $400, but then how much extra is the gas/regulator/tank, etc. I think this is why everyone goes for flux core welders since the gas stuff just adds on a ton of cost.

I want to buy a welder to do some panel work, but can't make up my mind on just getting a Harbor Freight flux core unit or getting the cheapest Eastwood unit and then getting all the gas stuff.

[bdahlg68]

Flux core is lower up front, but not necessarily cheaper. The wire is quite a bit more expensive and if you burn through a panel, well... Look for an Airgas, they're everywhere and they should be able to fill cylinders and may also sell them. I have a flux core unit that cost about $150 from Northern Tool. It's a great welder for the money, but I'd still rather have a MIG I can run 0.25 wire in. Plus, it only has 2 heat settings, and that just isn't enough for welding sheet metal. If you can afford to pick up a gas MIG, do it. If it's going to prevent you from being able to doing a project, you can probably get by with a flux core unit, but again, I don't think the final cost will be significantly different if you get a good deal on the MIG.

[ErikLS2]

I don't think you'll find too many people that bought a flux core machine for welding clean steel that didn't at some point wish they'd gone with a MIG to begin with. They're good for farm guys or building maintenance guys fixing gates and stuff, that's about it. Look on Craigslist for a used Lincoln, Miller or Hobart. The gas is a non-issue once you see how much use you get out of it and the much better looking weld it produces.

[robertjra]

I got a harbor freight welder for $59.00 used with a 2 yr warn.. it works ok but I will get a mig after all of you are saying how much better it works

[bdahlg68]

I'm actually quite happy with the Northern Tool flux core I have, so I'm thinking I'll eventually pick up their next step up MIG.

http://www.northerntool.com/shop/tools/product_200332691_200332691

and I like the cabinets they have too....

http://www.northerntool.com/shop/tools/product_200460615_200460615

and they sell cylinders...

http://www.northerntool.com/shop/tools/product_200317977_200317977

[absintheisfun]

I started off with a flux core/mig made by Clarke, and it treated me well for a good 3 years. I ended up getting a Miller mig and like many have said, I wish I would have done it sooner.

Flux has its place, but Mig is definately cleaner and easer.

As far as effect on paint, I've never heard anything about Flux being bad for paint applications. In the areas that I have used my flux, it has had no effect on my primer or filler.

[BuzzKillian]

As far as the gas goes... I got a 1200# bottle from Weiler Welding. It was $110.00 for 100 year lease and I just had it filled (read exchanged) for like $30.00.
I have a Hobart 175

[grenade inspector]

based on personal experience, flux cores are great farm welders but they aren't for works of art.

[elitecustombody]

I know it's different everywhere, but the thing about MIG is where do you get the gas? And how much is it? Yeah you can get the welder and wire for like $400, but then how much extra is the gas/regulator/tank, etc. I think this is why everyone goes for flux core welders since the gas stuff just adds on a ton of cost.

I want to buy a welder to do some panel work, but can't make up my mind on just getting a Harbor Freight flux core unit or getting the cheapest Eastwood unit and then getting all the gas stuff.

The regulator,gauges and hose are included with the welder.You can buy the cylinder for couple hundred or rent it from local welding supply store.If you're in Cali, it can't be all that difficult to find a store near you, because most of them supply hospitals,clinics and countless local shops that need gas everyday.I own a few tanks that are about 4.5 feet tall and it costs around $25 to fill one up at local Airgas.

[DarkoNova]

The regulator,gauges and hose are included with the welder.You can buy the cylinder for couple hundred or rent it from local welding supply store.If you're in Cali, it can't be all that difficult to find a store near you, because most of them supply hospitals,clinics and countless local shops that need gas everyday.I own a few tanks that are about 4.5 feet tall and it costs around $25 to fill one up at local Airgas.

Ah, see I didn't know the regulator, gauges and hose came with the welder. I just looked at the Airgas site and found out they have a store literally 10 miles from me. Gonna have to check them out next week!

[nekkidhillbilly]

northern tools are century built and century and lincoln are the same company

[elitecustombody]

And Hobart is made by Miller.

[John Wright]

the flux leaching out of the weld and effecting the paint. I'd be curious to hear an explanation for this...

The flux inside the cored electrode("gasless" FCAW) produces a shielding gas and also a slag system to further shield the molten puddle until it cools below a critical temperature. The slag also acts like a dam and helps hold the fluid molten puddle in place.
If you chip/brush/clean the slag off...how can it leach out? I think somebody is feeding you a line hoping you will take the bait.
70ksi steel is 70ksi steel whether it comes from FCAW(cored wire) or GMAW(solid wire) is irrelevant. Even if welded with GMAW, that can leave silicon islands on the cap of the weld bead and that must be removed before paint will adhere. GMAW is easier to use on sheet metal because it doesn't dig as deep as FCAW and allows you to weld on the thinner materials without burning through.

[elitecustombody]

^ I agree, if the weld has been cleaned up,it shouldn't affect the paint in any way.It's just that flux core is not ideal to use on car's sheetmetal.

[Happyfunballs]

FYI, I filled up my little bottle the other day (4ft tall) and it was nearly $60. Make certain you understand the bottle rental/purchase/lease agreement.

[elitecustombody]

Yeah, Praxair was raping me at almost $70 to fill up for years,until I sat down and called around and found best deal at Airgas for less than half

[Happyfunballs]

Airgas was $10 cheaper for the refill but wanted an yearly fee that was 5X the rate I currently have for 5 years. I've been with CeeKay for so long I was "grandfathered" into their good rates. Whatever.

[nekkidhillbilly]

And Hobart is made by Miller.

this is true also all are good welders the reconditioned northern migs are the best value for a good machine i can find

[David_viny]

Thanks for the response! I had a feeling it was BS. I used a stick welder to fix a few things on some random junker cars I had a few years ago and of course knocked off the slag, ground them down, and painted over them. The paint held up fine a few years later.

I just never used flux core, and it would have REALLY sucked if I welded up a whole car and it had paint issues.:hammer:

[John Wright]

In case you are wondering if FCAW is strong enough for structural work....this is for Princeton University and is being welded in my shop with E70T-1 w/100% CO2 shielding gas. 440amps/29.5volts @ about 15"/min. It took (4-5) 60# rolls of wire to weld each column like this one.

the Welder is Melvin and he has been with me here at this plant as one of our 40 welders for a little over 30 years.

[Happyfunballs]

Wouldn't it be cheaper to stick weld it? Less material costs for the same/more "bonding" strength? There must be a visual factor involved.

[John Wright]

Wouldn't it be cheaper to stick weld it? Less material costs for the same/more "bonding" strength? There must be a visual factor involved.

Stick welding is much more labor intensive so it drives up our manhours....then factor in 10%+/- stub loss, dramaticlly reduced speed of travel (5-7"/min for 5/32" E7018 vs 15-20"/min for 3/32" FCAW), and having to reload the stinger every 10-12" of linear weld vs a continuous 60# roll of wire. Stick welding is considerably slower and more expensive in all respects.
The base plates are 6.5" thick, flanges are over 3" thick and over 14" wide...I can't imagine having to fill a 45° bevel with E7018.....

[Happyfunballs]

Huh, ok. Interesting indeed.

[John Wright]

Sorry to sound so passionate about it...LOL...fabricating structural steel for highrise buildings is all that I've done my entire working career. I've done just about every position here from a general laborer, to programming equipment, to detailing and creating shop drawings from the contract drawings, to assisting the plant mgr with employee record keeping, and finally I've landed in the QC office as the mgr for the past 12 years performing all of the welder qualifications and weld inspection (visual, dye penetrant, magnetic particle, and ultrasonic testing).

[Happyfunballs]

Don't be sorry, I think it's truly interesting, although Melvin appears as if he could be happier doing something else. :lmao: If you ever need HSS, look us (http://www.bullmoosetube.com) up. :shamlessplug:

[John Wright]

another pic of Melvin (http://lynchburgsteel.com/?page_id=5) cutting some plate ::shameless plug::...LOL

[robertjra]

In case you are wondering if FCAW is strong enough for structural work....this is for Princeton University and is being welded in my shop with E70T-1 w/100% CO2 shielding gas. 440amps/29.5volts @ about 15"/min. It took (4-5) 60# rolls of wire to weld each column like this one.

the Welder is Melvin and he has been with me here at this plant as one of our 40 welders for a little over 30 years.
wow that pic is cool that would be sweet to work on stuff like that all day

[John Wright]

wow that pic is cool that would be sweet to work on stuff like that all dayTrust me...it's not so "cool" to weld on that material with around 450amps at arms length, in this heat, with the fans turned away to keep from blowing your shielding gas. I have to keep after the guys to stay hydrated....I'm sure they are tired of hearing me preach about drinking plenty of fluids.