DC help

[dstig1]

Miller - Stick Welding Calculator

Doesn't hit your questions on the additional settings, but is very handy and helpful for a quick look at amp settings. They also have a mobile app/website of it for all processes.

 

[rankrank1]

Typically, I think of it this way to help me:
AC = 50% heat into rod and 50% heat into workpiece.
DC electrode positive = 67% heat into rod and 33% heat into workpiece. (DCEP is most common polarity used and results in max penetration).
DC electrode negative = 33% heat into rod and 67% into workpiece. (rarely used, but helpful on thin sheet metal if no wire feeder and results in min penetration).

So what does it mean? In short for whatever setting that you were using on your old AC buzzbox take that setting and multiply times 0.83 for a rough starting point setting and adjust from there accordingly as needed. ( e.g. 100 amp setting on AC buzzbox would roughly equal 83 amps on DCEP).

 

[deereman75]

Ok thanks. The miller calculator helps, it is still quite rough though. Rankrank1s comparison of ac to dc helped me get my head around it a bit.

 

[yomax4]

Stick Welders are soooo..:confused2:. :thumbsup: lol..

 

[Shield Arc]

What is the safe way to weld in the rain or otherwise damp conditions?

To be safe, all you need is rubber gloves, and rubber boots. Rubber gloves are almost a must. A lot of guys would wear the thin rubber cannery / medical gloves inside their leather welding gloves.
Rain gear is for your comfort, but if you are working hard you'll sweat like a pig in rain gear, and be wet anyway. Even the cheapest rain gear gets expensive when burning it up welding. A lot of guys will wear their rain gear under their Carhartt coveralls / overalls. Around here far as I know if you're a certified weldor, you supply the first set of rain gear, and the union requires the contractor to replace any burned up rain gear. It always seemed to be a big problem, guys would buy very expensive Helly Hanson rain gear, burn it up, but the contractor would replace it with cheap Kmart crap!

 

[rhett]

I have no doubt that many people have welded in the rain. But this raises the question of how safe is it?

What is the safe way to weld in the rain or otherwise damp conditions?

work as a team with a helper/tender as Safety and Knife Switch Operator
only switch the power to stinger when positioned to weld, switch OFF when done with rod, changing electrode, getting back into position, etc...

never allow the currents path to cross your heart
been stung countless times with DC, still alive but an experience that will always be remembered

EDIT: if you have the metal fillings in your teeth, they will be tasted and if done allot plan on dentist visits to repair/ replace them

 

[Danno1]

Typically, I think of it this way to help me:
AC = 50% heat into rod and 50% heat into workpiece.
DC electrode positive = 67% heat into rod and 33% heat into workpiece. (DCEP is most common polarity used and results in max penetration).
DC electrode negative = 33% heat into rod and 67% into workpiece. (rarely used, but helpful on thin sheet metal if no wire feeder and results in min penetration).

So what does it mean? In short for whatever setting that you were using on your old AC buzzbox take that setting and multiply times 0.83 for a rough starting point setting and adjust from there accordingly as needed. ( e.g. 100 amp setting on AC buzzbox would roughly equal 83 amps on DCEP).

I think you got something backwards in here.

If DCEP has the most pen, shouldn't the heat be 67% into the work? And vice versa for DCEN?


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[rankrank1]

I think you got something backwards in here.

If DCEP has the most pen, shouldn't the heat be 67% into the work? And vice versa for DCEN?.

Nope not backwards, but you are welcome to prove me wrong as I am far from an expert and have never claimed to be anything other than a hack welder.

Really it is simply a matter of perspective:

First In the mechanical world:
a) a 67 pound hammer hitting a center punch will leave the biggest divot in metal.
b) a 50 pound hammer swung at same speed will leave a medium sized center punch divot in the metal
c) a 33 pound hammer swung at same speed will leave the the smallest center punch divot in metal.

Now in the electrical world.
a) DCEP will put 67% of the heat, oomph, power( whatever you want to call it) into the stinger and it will leave the biggest divot in the metal.
b) AC will put 50% of the heat, oomph, power (again whatever you want to call it) into the stinger and it will leave the medium sized divot in the metal.
c) DCEN will put 33% of the heat, ooph, power (again whatever you want to call it) into the stinger and it will leave the smallest divot in the metal.
(NOTE: In the electrical world there are not any signifigant mechanical losses like friction found in the physical world so the leftover heat is transferred to the workpiece as them amps do not just magically disappear - they have to go someplace).

 

[rhett]

darn, I have way to much free time

The Welding Handbook for Maritime Welders :thumbsup:

 

[Danno1]

Nope not backwards, but you are welcome to prove me wrong as I am far from an expert and have never claimed to be anything other than a hack welder.

No, not trying to prove you wrong at all. Just trying to understand.

I'm a hack welder too!!!


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