The welder selection decisions?

[Papa Charlie]

OK - for us beginners, I take it that means changing the wire spools is a right Royal pain!
Sufficient to motivate buying a whole other welder!
Thus perhaps suggest the generally most useful size. I get it that if you want to weld car body sheet metal together in a butt joint stitched weld, you will likely need the thinnest.
What suits 2mm wall angle or box?
What about 3mm thick 40mmx 40mm angle?
What goes with 6mm (or 1/4 inch) 2"x 2"

Suppose you have a "thick" weld to make, say approx 10mm (0.4"), and you have it beveled, and a root butt, and you want to do a multi-pass
What spool size?

Also, while we are at it, how to stop it curling up together as if to close the joint.
Is this kind better done as a stick weld?

Changing wire is not difficult at all. Cut the wire, pull the spool, pull the wire out of the gun lead, insert new wire sppol. loosen the drive tension, push the wire through, push button for cold feed, adjust tension and close the door.

I have only had an issue when the gun feed sleeves start to wear out and need to be replaced.

 

[Lo-Fi]

OK - for us beginners, I take it that means changing the wire spools is a right Royal pain!
Sufficient to motivate buying a whole other welder!
Thus perhaps suggest the generally most useful size. I get it that if you want to weld car body sheet metal together in a butt joint stitched weld, you will likely need the thinnest.
What suits 2mm wall angle or box?
What about 3mm thick 40mmx 40mm angle?
What goes with 6mm (or 1/4 inch) 2"x 2"

Suppose you have a "thick" weld to make, say approx 10mm (0.4"), and you have it beveled, and a root butt, and you want to do a multi-pass
What spool size?

Also, while we are at it, how to stop it curling up together as if to close the joint.
Is this kind better done as a stick weld?

I do all that with MIG, 0.8mm wire. I often can't be bothered to change to the 0.6mm wire for thinner car body gauge stuff and stick with the 0.8mm to be honest. You just need a lower feed rate. Welding at lower amperages is nicer with the thinner wire - it's just a little more smooth - but I'm a hot, heavy, speedy type of welder, so the thicker wire isn't a problem. It's not that much of a faff to change spools - maybe ten mins (once you've unpacked the other spool, wound the wire back, changed the nib, swapped the spools, fed the wire again, set the rollers for the correct wire gauage). I'm lazy!
Anything over 5mm is best done with multi passes on a hobby machine. Indeed, even my welding qualification works that way. 12mm plate, root pass, stringer filler passes, weave cap. You can do those with TIG, but you're going to use a lot of gas and take a month of sundays. Depends what you're doing for which technique you choose.

 

[Aaron_W]

Most if not all the welders you would be considering can run .024", .030" and .035" solid wire (metric 0.6, 0.8 and 1mm?). MIG is fairly forgiving of wire size, so if you were doing a bunch of sheet metal and had .024" wire loaded in the machine, but had a couple 1/4" welds to do, not a big deal, as long as you were ready for it to run a high wire speed. Not as efficient and you will run through more wire, but it would work. Now if you were moving to a project that was all 1/4" metal it would be worth changing spools.
Inconvenient is a better word for spool changes, it isn't hard. I do mostly 1/4" and smaller so just run .030" all the time. It is a nice middle ground that will work on sheet and 1/4" +. If I was going to do something with a lot of 1/4 to 3/8 then I would probably go buy a spool of .035". I have a small spool of .024" for thin sheet but I've never used it.

 

[pontiac428]

I was just teasing Zod for having 3 (or more?) MIG welders. I have 4 different MIG guns set up with the right tips, nozzles, and liners to cover wire from .045 down to .018. I use the .045 to spray-transfer flux core using 2% O2 gas mix for heavy structural work. I doubt you can do spray transfer deposition with a lunchbox welder, those are short-circuit transfer mode machines.

 

[Janderso]

TIG is the most difficult to learn and yes, everything has to be clean. I have to be in a comfortable, stable position to see the tip of the tungsten. I haven't tried the lift arc or the other TIG start setting on my 220 acdc. Just the peddle. You have to be in a position to operate the peddle.
If you are on a farm or out on a construction site in the wind repairing equipment, let's not forget about arc welding.
I guess flux core MIG would be comparable??

 

[Aaron_W]

TIG is the most difficult to learn and yes, everything has to be clean. I have to be in a comfortable, stable position to see the tip of the tungsten. I haven't tried the lift arc or the other TIG start setting on my 220 acdc. Just the peddle. You have to be in a position to operate the peddle.
If you are on a farm or out on a construction site in the wind repairing equipment, let's not forget about arc welding.
I guess flux core MIG would be comparable??

My instructor in the TIG class that got cancelled halfway through, described TIG welding as like patting your head and rubbing your tummy while trying to tap your toe to the beat. I found that a pretty accurate description, there is a lot going on. I need a lot more practice to get past barely marginal at it, I can't dance either.

 

[General Zod]

Lots of devoted brand-loyalty in evidence, but also, given three of them appear to be identical, this stash of welders are likely the tools of a whole site crew.

Nope all of them are in my garage with the exception of 1 that I gave to my Dad.

 

[graham-xrf]

I was just teasing Zod for having 3 (or more?) MIG welders. I have 4 different MIG guns set up with the right tips, nozzles, and liners to cover wire from .045 down to .018. I use the .045 to spray-transfer flux core using 2% O2 gas mix for heavy structural work. I doubt you can do spray transfer deposition with a lunchbox welder, those are short-circuit transfer mode machines.

Do tell about spray transfer deposition?
OK - I guess I can search on YouTube to learn about it, but I want to discover if the technique is exclusively the preserve of large firm industrial processes.

"Lunchbox welder" as for perhaps stitching some car body at 85A, or welding up a bench frame at 120A, I can understand, might be out of their league.
What minimum capability in a welder is viable?

 

[graham-xrf]

Nope all of them are in my garage with the exception of 1 that I gave to my Dad.

OK - so given I have some imaginative difficulty in visualizing the volume application needs, that must mean you love the art, and have built a collection of welding kit of nuanced capabilities, from the most minimal through to the most exceptional. That, short of welding ship sides or railway lines!

I trust that each one has some feature that is a bit different from it's predecessor. I guess a new style model or technology is something you can't manage to walk away from.

I know I can be prone to "shop envy", and "machine envy", but now I encounter "welder collection awe"!

 

[General Zod]

Spray Transfer is awesome (for flat/horizontal). Very high energy mode of transfer. Using an Argon rich mix (typically 82% Argon minimum, balance CO2, optimum usually 90%+ Argon, balance CO2, but one can also use Argon-Oxygen with O2 being in the 2-5% range), one can have both the voltage and amperage cross a threshold where by the wire no longer contacts the part and instead tiny droplets (whose diameter is less than the diameter of the wire) get pinched/propelled off the end of the wire across a continuously lit electric arc. The high E-M forces cause the droplet to be driven axially, so the direction of deposition is controlled.

The bad part is that the puddle is so hot and fluid that it is limited to flat/horizontal. But that is where pulsed-spray mode of transfer comes into play.