View Full Version : Why is DC necessary?
12-27-2002, 07:47 PM
I just received a Hobart Stickmate 235 AC. I see they also make the same with AC and DC. I am new to welding and wonder what the benefit of DC would be? Thanks
12-27-2002, 09:59 PM
One of the advantages of DC is that the arc is much"quieter" I know that this may not make much sense if you have no experience in running both AC
and DC machines.
If you can, go to a friend's who has a DC welder use it a bit after you are comfortable with yours
and see if you can notice the difference.
As to the technical reasons why DC is nessasary, this is better answered by one of the other members here,(MIKE SHERMAN, HERE'S ONE FOR YOU)I knew this stuff 25 years ago, but it's not on the top of my mind right now. Ed.
12-28-2002, 05:39 AM
AC is alot harder to run. DC is smoother & alot easier to start. There are only a few different rods that will work well on AC.The main reason, if I remember correctly is the elelcrical pattern for AC & DC. AC cycles back & forth between Pos.&Neg current as with DC it cycles only on the pos. or neg. side which makes for a smoother arc. Also some ofthe more common rods like 7078 & 6010 are made to be a DC only rod. You can use 6011 & 6013 with AC. There are more rods avail. for AC, I just can't remember what they are. John
12-28-2002, 09:13 AM
With DC you can stick weld stainless steel and cast iron. You can also stick weld aluminum. I have not had great success stick welding aluminum, but you can do it.
12-28-2002, 09:17 AM
I had an AC welder for 12yrs it worked fine and never gave me any trouble. For practical purposes the difference is AC starts the weld easier, but you (I) tend to stick the rods a lot due to the changing magnetic field of the material-electrode. Alternating current cycles back and forth about 60-120 times a second. Direct current only flows in one direction and is a bit harder to start, but you can keep the arc going more easily. You do get a little arc blow sometimes, but it is usually no big deal. Blow is where you find the arc wondering away from the electrode (usually not where you want it to go,,lol) A weld from either machine will work just as well as one from the other,
12-29-2002, 09:17 AM
Thanks for the info.