Which process for thick metal? Stick, TIG, MIG?

[raferguson]

In my shop, I have around 200 amps output on stick, tig, and mig. My question is when I weld thick metal, which process should I use? I was looking at my welding books, and ended up confused.

For thick steel or stainless, I figure stick, so that it easy. I could probably stick weld one inch plate with 200 amps, use 5/32 inch rod, just use multiple passes. TIG must be last choice, with MIG in the middle, basically in terms of amps required for thicker steel. Anyone vote for MIG?

For thick aluminum, it is not so obvious. I am pretty sure that TIG requires the most power, and stick is not recommended for aluminum, so I figure that MIG must be the answer, but not sure. Maybe it does not matter, both TIG and MIG require a lot of power for thick aluminum plate.

I weld a lot of copper, which takes more power than aluminum of the same thickness, since it conducts heat better, so I think that the answer would be the same as aluminum. (I TIG copper frequently, DC using Argon, have never use MIG on copper).

I don't consider oxy-acetylene for thick metal, impractical, although it used to be used for that purpose, before World War II.

So what say you? Does it matter which process you select when your machine is marginal on power? Personal preference?

This is related to my earlier question about high amp welders for a home shop.

Richard

[snoeproe]

For thick steel no question... it's stick for me.

[1316 4 LIFE]

You are low on power for thich material. No fear, you can prep your material in different ways to support a good MIG process. Bevel and pre-heat. If your machine can handle a 3/16 or 1/4 fillet you will be able to bevel and pre-heat for almost any thickness. The range and heat will very based on the material thickness. Rule of thumb for 1/2 plate, bevel 3/8 at 60 degrees, with a 1/8 root opening, and pre-heat at 150. Good luck.

[DSW]

A good friend of mine does 1" + all the time where he works. At the shop it's all mig hands down. In the field it's split almost evenly between mig and stick.

Mig has less time lost to cleanup and prep between passes and is faster laying down metal. In the shop where you don't have to worry about a breeze and can get the machine to the part easy theres no question what to use.

In the field to use mig we need to tent the job to stop the breeze from blowing away the shielding gas. On big welds it pays to take the time to do this. On the other hand frequently getting where we need to go to do the weld is a PITA and stick wins hands down there as well as on small jobs wher we only need to do a small repair.

[DesertRider33]

Since the question is specifically referring to THICK metal, here goes...

Thick steel can be done equally well with stick or big fluxcore wire. Fluxcore is alot faster, but you won't be running big fluxcore wires with your 200 amp mig machine, so stick is your best choice for thick steel.

Most folks don't have the juice to run truely thick aluminum with ac tig and most are not skilled with dc tig on aluminum. Your 200 amp ac tig is too small for truely THICK aluminum. In your case, mig wins on thick aluminum.

As for solid wire mig, if you have the juice to spray it, then solid is fine for thick steel. If you don't have the juice to spray, you're limited to short circuit, which isn't the process to use for thick metal. Your 200 amp mig can do some limited spray with a spray mix gas (98/2, 95/5, 92/8). If your torch is light, you may end up melting it doing much spray with it. Basicaly, for your purposes, solid wire mig is not the best choice for thick steel.

To conclude, for your specific equipment availability, concerning truely THICK metal...

For steel, use stick
For aluminum, use mig

Other folks, with more capabilities, have more options available.

[weldgault]

Flux core with CO2, reverse polarity DCEP. 200 Amps and 26 volts - 3/4 ESO. JG

[weldgault]

.045 Flux core with CO2 Gas. DCEP, 200 Amps, 26 Volts and 3/4" ESO. JG

[Fat Bastard]

Originally Posted by weldgault

.045 Flux core with CO2 Gas. DCEP, 200 Amps, 26 Volts and 3/4" ESO. JG

Flux core what?

NR211 NR 212 Core 8

Flux Core is not typically run with shielding gas

Duel shield is.

You are not helping, you are confusing.

[specter]

I always use stick for the thick stuff. Yeah its a bit more prep & cleanup but I always get better penetration. If I want the weld to look pretty for the customer I'll finish with a 7018 stick.

[sn0border88]

Originally Posted by Fat Bastard

Flux core what?

NR211 NR 212 Core 8

Flux Core is not typically run with shielding gas

Duel shield is.

You are not helping, you are confusing.

You are the one thats confused, flux-core is run with a shielding gas, but its designated as gas shielded flux core. FCAW-G vs. self shielfed flux-core which is just FCAW or sometimes FCAW-S

Dualshield is a trade name created by ESAB I believe, not the name of a process.

I would suggest getting a 98/2 or 95/5 mix gas for spray MIG is most of what your doing can be done in the flat position. If not, stick is probably your best bet. If you would have a slightly bigger MIG machine then gas shielded flux-core would be my first choice. Its fast, easy and involves almost no cleanup. But for now id say some 5/32 stick is your best choice.

For AL your only real choice is getting a spool gun for your MIG machine, your TIG just wont have the power do to much over 1/4 without a substantial preheat and/or bevels.

[farmersamm]

I think Dualshield is a Lincoln tradename. It is run with sheilding gas, but I would assume that's a real problem outdoors. Most flux core applications are outdoor unsheilded due to the wind problem.

Maybe with my eyes, I've actually found the slag benificial when welding. I can look at the boundary between the cooling slag, and the puddle, on a wire weld and see the profile of my bead. LIncoln's Excalibur rods also show a definite line between molten puddle and slag. I believe it's a design feature of the flux coating.

[farmersamm]

And I think flux core is used in situations where penetration is important.

[Fat Bastard]

Originally Posted by sn0border88

You are the one thats confused, flux-core is run with a shielding gas, but its designated as gas shielded flux core. FCAW-G vs. self shielfed flux-core which is just FCAW or sometimes FCAW-S

Dualshield is a trade name created by ESAB I believe, not the name of a process.

I would suggest getting a 98/2 or 95/5 mix gas for spray MIG is most of what your doing can be done in the flat position. If not, stick is probably your best bet. If you would have a slightly bigger MIG machine then gas shielded flux-core would be my first choice. Its fast, easy and involves almost no cleanup. But for now id say some 5/32 stick is your best choice.

For AL your only real choice is getting a spool gun for your MIG machine, your TIG just wont have the power do to much over 1/4 without a substantial preheat and/or bevels.

Well when Flux Core is run with out gas what is it called FCAW (with out gas) No it is FCAW and maybe FCAW-S.

So you saying that FCAW is run with gas is wrong and confusing, and to add gas to FCAW not intended to have gas added can cause serious issues with the chemistry of the weld metal.

A power source with limited power will do better with a process with out gas than with. So your suggestion of adding gas is wrong as well.


The best bet for welding anything is to do it with the process you are most confident with.


So quit confusing people please.

[raferguson]

My Modern Welding textbook just uses GMAW - Gas Metal Arc Welding, and FCAW - Flux Core Arc Welding. One quote is "Shielding gas may or may not be used when FCAW." They also talk about Self Shielded FCAW and Gas Shielded FCAW. So I take it that if you used Flux Cored wire with gas they would still refer to it as FCAW. I assume that the polarity with flux cored wire is the same with and without gas, but I don't know.

My Lincoln catalog uses the phrases "Gas Shielded Flux Cored Wire" and "Self Shielded Flux cored wire", similar to my Modern Welding book.

I know that Self Shielded FCAW is recommended for thicker material, but I know very little about Gas Shielded FCAW.

Richard

[sn0border88]

Originally Posted by Fat Bastard

Well when Flux Core is run with out gas what is it called FCAW (with out gas) No it is FCAW and maybe FCAW-S.

So you saying that FCAW is run with gas is wrong and confusing, and to add gas to FCAW not intended to have gas added can cause serious issues with the chemistry of the weld metal.

A power source with limited power will do better with a process with out gas than with. So your suggestion of adding gas is wrong as well.

What are you rambling about? It sounds like you are saying the same thing as me. My point is this, dualshield is not the name of a process, at all. Its the trade name of a brand of wire made by ESAB. Along with Lincolns gas shielded ultracore and outershield (just to name a few)

The abbreviation FCAW covers both self-shielded and gas-shielded flux cored electrodes. The designation is made with either a -S (self-shielded) or -G (gas-shielded)

Obviously you shouldnt run -G electrodes without gas or -S electrodes with gas, I never suggested you should. And using CO2 shielded fluxcore wire will give better results than running the same dia. wire in a self shielded version. The gas helps in transferring heat to the base metal, especially with CO2 due to the dissociation property. More heat=more penetration Sure you might need to run a few more volts but a 200A machine should be able to handle that. Not to mention its cleaner and faster. Not knowing his exact machine its hard to make a good recommendation but what I said isnt necessarily wrong.

EDIT: Ill admit he might not have the power to run .045 gas shielded, but if he does than that would be my first choice.

Originally Posted by raferguson

So I take it that if you used Flux Cored wire with gas they would still refer to it as FCAW.

Yes, generally they do but if someone wants to clarify it will end in a -S or -G

Originally Posted by raferguson

I assume that the polarity with flux cored wire is the same with and without gas, but I don't know.

No, it is normally DC+ for gas shielded. Self shielded is usually DC-

Originally Posted by raferguson

I know that Self Shielded FCAW is recommended for thicker material, but I know very little about Gas Shielded FCAW.

I disagree, FCAW-G shines on thick material. Its much faster and cleaner than stick or FCAW-S because of high deposition rates, virtually no post weld cleaning and you can push quite a few amps through it getting very good penetration.

[bratkid63]

For me, thick steel, stick all the way. A bit more work, but usually a lot more economical. I don't have anything against MIG (I use it all the time) but I'll grab the stinger for anything over 1/2".

Funny, but I get more satisfaction watching the slag remove itself from a well laid 7018 stick bead, than I do laying a MIG weld.

[farmersamm]

What's the big fuss about. Flux core is sometimes run with shielding gas if the wire is designed to be run with shielding gas.

Using a trade name to describe the process is perfectly acceptable. Dual shield, to anyone that knows a thing about welding, means using gas with a flux cored wire intended to be used with a shielding gas.

As far as "thick" material. My opinion, for what it's worth...............................

Any thing over 12ga metal should be welded with SMAW...................STICK. I am, of course, talking about mild steel......my material of choice because of what I do. Nitpickers can have at it, but I'm stickin' with it.

I know that todays wire machines will produce a fine weld on thicker material. But the majority of the readers here may own smaller "Pocket MIG's", little 110v machines.

I do not believe in voicing an opinion which could lead people to believe that smaller machines are satisfactory for use on thicker material. I know there's more powerful machines out there, but the majority of the folks on the forum own smaller machines. (I think)

The basic stick welder is the best thing for thicker material. Good penetration, and fast filling. I know you can dump a ton of wire on a long weld, but for most things the stick is best for thick stuff.

Well, that's my two cents (corrected for inflation)

[sn0border88]

Originally Posted by farmersamm

What's the big fuss about. Flux core is sometimes run with shielding gas if the wire is designed to be run with shielding gas.

Using a trade name to describe the process is perfectly acceptable. Dual shield, to anyone that knows a thing about welding, means using gas with a flux cored wire intended to be used with a shielding gas.

Your right, it is. Hell I say dualshield all the time. But if FB is going to pick on someone else for not using the correct term then he ought to at least get it right himself.

Originally Posted by farmersamm

Any thing over 12ga metal should be welded with SMAW

Seriously? I dont know of any machines that are rated only to 1/8" Most 110v welders are capable of more than that, much more if they employ the double bevel and open root joint prep you speak so highly of. Any 220v MIG machine can easily do 1/8 and thicker.

Originally Posted by farmersamm

The basic stick welder is the best thing for thicker material. Good penetration, and fast filling. I know you can dump a ton of wire on a long weld, but for most things the stick is best for thick stuff.

And why is it better than say a wire machine capable of welding the same thickness? Im not saying your wrong, just curious as to how you came to that conclusion.

[farmersamm]

You have some good valid points too

I tend to favor stick because it's a pretty simple process, and doesn't involve automation. Parameters on stick welding are a little more forgiving. Wire welding requires good familiarity with proper parameters required by the machine and material.

Another factor is entry cost. Stick welding is cheaper to tool up for, and is really pretty versatile.

Wire welding seems to be a game of chasing the power. You're always looking for that extra bit of power, at an increasingly higher cost. Whereas the stick welder already has all the power you need in the original package.

I'm biased Or at the very least halvazzed

[DesertRider33]

A good amount of structural fabrication these days is done with big fluxcore wires pushed by higher power machines cause it's alot faster than stick and time is money. All the heavy framing on the school buildings job I was on was done with thick NR232 wire in LN25's powered by Pro 300's. My buddy and I were welding the metal stud framing on that job, using .035 T-GS with our Passports. 5 welders (3 on the iron crew, 2 on the framing crew) put up 14 buildings in about 3 months with fluxcore. I doubt we could have done it anywhere near that fast with stick.

I agree stick is far simpler and cheaper for the equipment, simpler to run too. I'm learning T8 wire now and every little variation seems to affect it more than other wires I normally use. The bigger wire size is something new for me too, alot more puddle to control.