[TheForge] more welding 60xx
Paul Sperbeck
forge at wi.rr.com
Thu Dec 15 22:31:56 EST 2005
Frosty said:
A couple things about E60xx rods:
They don't generally make pretty welds, they're generally heavily ridged. It's
one reason folk overamp it, trying to get it to lay smoother.
You HAVE to weave/flag. (whatever moving the rod around to keep the puddle
where it needs to be is called these days) Whether you're welding with a
torch, mig, tig or stick the same basic rule applies: Make a puddle THEN fill
it in.
<snip>
I like 6010/6011 rods. More than likely because that's what I cut my teeth on. Never had 7018 to use till the early 70's. As Frosty pointed out previously, the 60xx series is not known for beauty and ease of use. What is dose do is put the weld deposit pretty much where you point the rod... a blessing and a curse.
The 60xx series are fast freeze rods. When run in the proper current range they work in all positions, but the weave used in the vertical up and overhead welding is different than that used in a flat or horizontal position. One of the characteristics of constant current stick welding is that the longer the arc the hotter the arc is, but not much metal is deposited, the shorter the arc is 'cooler' but deposits more metal (we are talking very relatively here.. a short arc is close to the point where the actual arc is lost because the rod has 'shorted out' to the workpiece, and a long arc is near the distance that would cause the arc to extinguished because has become so far away the from the workpiece that the arc is 'broken')
Combine the directional characteristics of the rod, point and deposit, and the hot/cold thing and you discover the reason for the whip/weave that is mentioned.
In the case of vertical up, the longer arc is used to preheat the area ahead of where you are depositing metal, the action of moving the longer arc ahead (up) of the puddle allows the recently deposited metal to cool down some and when you return to the last puddle, and tie the now short arc into the aforementioned puddle, you tie the puddles together. Hence the little rings of a properly made 60xx weld. This all happens very quickly....
The long/short arc thing is not so much a matter of pulling the rod away as it is allowing it to 'burn' farther away from the work and then 'pushing' it in to the work a little farther along.
I like the rings... a sign of a good welder is the consistency of the puddle, i.e. all the rings are pretty much the same size and shape.
Using the proper current makes these rods behave, but many of the buzz boxes have very low open circuit voltages. This makes the rods hard to start.
The voltage of a weld in progress is pretty much fixed by the arc resistance and the ability of the power supply to supply enough voltage to hold the current constant.
Within the capabilities of the machine once the arc is operating, the power input to the welding circuit is the same.
Smaller currents equal less spatter and better control. If you need to fill a larger area than the rod will handle, use multiple passes, stinger beads, to build up the amount of weld metal rather than using a larger rod.
Here is why...
E=R*I
VOLTAGE = RESISTANCE times CURRENT
fer instance
given 100 amps (constant current source}
and say we have an arc resistance of .1 ohm that would require 10 volts from the welder
now say we increase the arc length and the resistance goes to 1 ohm
that would require 100v to maintain the 100 amp output of the constant current welding machine...might be possible but most welders crap out around 60-70 volts, and a lot of the buzz boxes can not do much better than 20 or thirty volts, maybe less. That means the the current is not going to be constant any more. At some point the arc resistance has increase to such a value that the welding machine cannot put out enough voltage to maintain the current and the arc goes out.
The arc resistance values are not actual, but show the relationship...I used those numbers cause they are easy to multiply.
now look at the power (watts).
.1 ohm * 100 amp = 10 volts 100 amps*10 volts= 1000 watt
1 ohm * 100 amps = 100 volts 100 amps * 100 volts = 10,000 watts
Even though the welder cannot get to 100 volts this illustrate that the power into the welding rod circuit goes up as the arc increases length, it also gets hotter...more wattage.
It is also why the arc goes out.
As you try to pull a longer and longer arc, you reach the point when the welder cannot put out any more voltage, the wattage requirements of the arc are going up and you need a larger welder to keep up...naw... just use a shorter arc.
--
Paul C. Sperbeck
My Grandfather was a blacksmith,
...and It didn't do me one damn bit of good.
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