by Jason Becker
One of the questions I get a lot as an educator is how do I set up my machine?
So today we're going to talk about shielded metal arc welding specifically with the low hydrogen electrodes and we'll just go over the basics.
I'm going to show you how to dial in the correct amperage or a good place to start regardless of diameter and position that you're going to be running in with low hydrogen electrodes. So for example we're going to start off with this 3/32" 7018 rod. So we can do that by figuring out the decimal equivalent to the electrode. So for a 3/32 electrode we just take the 3, divide it by the 32, and wind up with 93, .093. So a good place to start is 93 amps for the flat position.
Now if I wanted to go into vertical let's say good rule of thumb is to reduce that starting amperage and flat position by 10%. So if I take that 93 amps and I multiply it by .90, I end up with 84. So a good place to start is 84 amps for vertical.
Same thing with overhead, but I only want to reduce overhead by about 5%. So same values, at 93 starting amps, multiplied by .95, that's going to give me 88 amps. And that's a good start for overhead.
We're going to demonstrate and show you guys by putting these exact values in the Everlast over here and we're going to produce these welds. We'll do a horizontal, vertical, and overhead with the 3/32 as well as the 1/8 inch electrode.
So same thing when we figure out the diameter or the starting amperage for the 1/8 inch, start with the decimal equivalent so that 1/8 so one divided by eight, it gives me .125. Just get rid of the decimal. I have 125 amps of starting amperage, a good place to start for flat and horizontal.
Same thing if I go into vertical. Remember that 10 percent rule. I'm going to reduce it by 10 percent. So 125 multiplied by .90. It's going to give me 90 percent so it's about 113 amps for the vertical position on an 1/8 inch electrode.
Same thing with overhead, just reduce that by five percent of your original flat position amperage. 125 multiplied by .95 is going to give me 118 amps. So we're going to go ahead and show you guys.
We'll start off with the 3/32, flat, vertical, and overhead or horizontal, vertical, and overhead, and then we're going to do the 1/8 inch, horizontal, vertical, and overhead. So we're going to start off with a 3/32 electrode in the horizontal or 2F position. If you remember our calculations from a second ago, we discovered that that was about 93 amps. I've got my work piece clamp plugged into the negative side which is going to give me about thirty percent of my heat to my base plate. The electrode is plugged into the positive side where the remaining seventy percent of that heat is going to go into my electrode.