Stick electrode thickness

[walker944]

Quick ignornant question....

Are thicker electrodes hotter or colder than thinner electrodes? I can formulate an argument either direction in my mind, but don't have enough experience with or knowledge of SMAW to know which it is. I'm sure there is some good references on the web, but if some of you experienced stick welders could chime in I'd appreciate it.

My guess is thicker = hotter.

[Hammack_Welding]

As a general rule, When using a larger electrode it takes more amperage to pull the rod than the same rod in a smaller diameter. When welding thicker materials you will go to a larger rod to add more filler as well as more heat.

[David R]

A lot of books say for more penatration, use a smaller rod. I don't exactly get it. Running 1/8" around 140 amps, or running 3/16" at 220 amps, which gets more penatration?

The weld puddle should be about the same temp for both sizes. With the bigger rod, you are welding "faster" as in more metal being deposited.

Good question

David

[Hammack_Welding]

Well it depends on a lot of factors when considering penetration. Say if you take a 1/8" Vs. 5/32" rod both at 160A the smaller rod will penetrate more, but You turn that 5/32" up to say around 180-200 and the tables turn. You also have to consider travel speed, as well as technique. Lots of things effect penetration in my opinion.

[walker944]

Yeah, that was the other side of the arguement in my mind. So, I suppose the logic is that the thinner the rod, (given the same amount of electricity) the hotter, is because the electricity is confined to a smaller area, and is not dispersed along a larger rod area....if that make sense.

[ChamferTrode]

Technically neither, an electrode's size has nothing to do with how "hot" it is,
A larger diameter rod needs more amperage to melt and transfer across the arc, but this is not "heat". You choose a rod based on the thickness of the weldment and/or how much time you want to spend welding and energy you want to put into the workpiece. You wouldn't choose a 1/8" rod to weld 1/8" stock, as the power required to melt the rod is so high you'd also risk blowing holes in the base metal. And you wouldn't choose the 1/8" rod to do a heavy section machine base, as the low amperage required to not turn your electrode into a smoking noodle is insufficient to penetrate the base metal. Now you could bevel the heavy section and use the smaller electrode at it's lower power, but that means multi-passes with chipping and cleaning between passes and also more heat into the work, by using a sufficient sized rod you are only adding enough heat to do the job, once, and it is sinked away without a large HAZ, (heat affected zone)

[Hammack_Welding]

Chamfer, You are correct. I think by "Hotter" Walker actually is referring to penetration rather than the temp of the weld itself. Atleast that was my interpretation.

[ChamferTrode]

Hammack, if that's true, then it's more dependent on electrode composition, polarity, and running it within parameter, not size. a 3/32" 6010 run at 70A reverse will out penetrate a 5/32" 6013 run at 140A DCEN

[walker944]

Yes, I was referring to penetration when I used the word "hot" in reference to the electrode. Camfers words are a good explanation of what I was looking for. I understand each rod thickness is used typically within a metal thickness range, but wasn't sure whether there was a relationship between weld penetration and rod thickness, assuming all other variables being the same.