The welder selection decisions?

[graham-xrf]

@NortonDommi : OK - so we know that straight AC welding is sparkier, and produces more spatter. By comparison, a DC weld is smoother, and goes on steadier. Yes OK - addition of diode rectifier to a low cost transformer lets you have the choice.

Is there a right polarity? Which end should be positive? Does it not matter, just so long as it's DC?

 

[addertooth]

It super matters the polarity. The the term is DCEN Direct Current Electrode Negative for flux core wire.

There are reasons and purposes for positive polarity. So this applies to typical flux wire welding.

 

[Aaron_W]

I can't entirely argue. There are more old car guys, than old car gals.

The harsh reality of this was brought home to me when I went car shopping with my wife.

Me: What are you looking for what do you like? (thinking maybe she has some idea of a particular car she likes).

Her: Maybe a blue one, and I want cup holders.

Me:

 

[erikmannie]

Regarding the bulb-shaped handle made out of a spring on many slag chippin’ hammers, I was just wondering about this myself last weekend. I found this online:

“The coiled spring handle provides maximum comfort by reducing impact sting.”

I had thought that it was for heat dissipation.

 

[Liljoebrshooter]

This thing is probably most hated tool I have owned. Every time I used it my hand would hurt from trying to grip it. I bought a nice wooden handle one and it is very nice. You can also buy one with the chipping edge in either direction.
As for a welder, buy a good sized MIG and don't look back. At some point you may need to weld a very thick piece or you want to start into aluminum and stainless, then you can look into a TIG machine.
Joe

 

[NortonDommi]

@NortonDommi : OK - so we know that straight AC welding is sparkier, and produces more spatter. By comparison, a DC weld is smoother, and goes on steadier. Yes OK - addition of diode rectifier to a low cost transformer lets you have the choice.

Is there a right polarity? Which end should be positive? Does it not matter, just so long as it's DC?

Depends on material being welded, type of rod, position. All manufacturers have the information readily available on their sites and with FCAW it is also on the box the rods come in. Some rods are happy with anything the Blue Guys can run through some are very picky which way they run. Bit of info here: https://www.twi-global.com/technica...welding-which-electrode-polarity-should-i-use

 

[erikmannie]

Another case for starting with oxyacetylene: you get to skip any consideration of polarity.

SMAW: You sacrifice almost nothing by limiting yourself to E6010 and E7018. Under those circumstances, you could just leave your stick welder set to DCEP for your whole life.

TIG: DCEN for carbon steel, SS & Ti, and AC for aluminum.

MIG: DCEP.

FCAW: DCEN.

Some helpful tips:

(1) Learn that TIG on carbon steel is DCEN, and then remember that MIG is opposite of that.

(2) Here’s how it makes sense:

I first learned to weld with TIG on carbon steel (DCEN). The idea there is to put heat onto the base metal so that it will puddle. DCEN means “electrode negative”. The tungsten is the electrode so it has a negative charge. Thus, the workpiece has a positive charge. So all of the electrodes are attracted to the workpiece; this results in a bombardment of electrons on to the workpiece which causes heat (and puddling).

If you had your TIG machine set wrong, then the opposite would occur and you would be mostly serving to heat up your tungsten electrode. This would not help you get a puddle on your workpiece.

 

[7milesup]

To me, Oxy-acetylene is a PITA. Sure, it prepares you for TIG welding maybe, but in my opinion, just buy a TIG then. For what it is worth, I have never seen anyone Oxy Acetylene aluminum together.

 

[7milesup]

They have nylon liners for alum wire, but it can still be a sketchy deal. Spool gun is definitely the way to go if you can afford it, and prices have been coming down some. Mike

Correct. All I said was it can be done without a spool gun.

 

[erikmannie]

Some people buy an economical AC stick welder (often a Lincoln Tombstone (buzzbox)) because they anticipate the need to run E6011 (for penetration and/or a dirty workpiece). The people with these machines will then run 7018AC for structural applications, and they also have the option of running E6013 for thinner workpieces.

A lot of DC stick machines don’t have enough open circuit voltage (“oomph”) to run E6010, but fortunately most or all machines will run E6011 no problem, and E6011 is almost as good as E6010.