Hi everyone
Can someone explain these results from measuring arc voltage while "stick" welding?
All 2.5mm (3/32nd-inch) diameter:
+-------------------------------------------------------+ |7018 |Bohler EV50 |22V |72A| |---------+---------------------------------+-------+---| |6013 "R" |straight rutile |25V |62A| |---------+---------------------------------+-------+---| |6013 "RC"|Zodian Universal rutile-cellulose|21V |76A| |---------+---------------------------------+-------+---| |6010 |Foxcel |30V |62A| |---------+---------------------------------+-------+---| |6010 |Foxcel - wet |28V |64A| |---------+---------------------------------+-------+---| |6011 |Arcos Nu5 |20V-25V|62A| |---------+---------------------------------+-------+---| |6011 |Arcos Nu5 - wet |30V-35V|63A| +-------------------------------------------------------+Welding machine was Murex Transtig AC/DC 250HF on polarity DCEP set to 20% on the 20A-320A range. (this is essentially a copper-and-iron transformer machine whose thyristors, etc, feature when AC TIG welding (?))
As you can see, the cellulosics are at the bottom of the table and the really interesting results are the last two.
So what is going on here?
In UK technical colleges, I have long known that dipping their "standard" cellulosic rod, 6011 "Arcos Nu5", in water transforms the performance, giving a deeply penetrative roaring "cellulosic" arc where sometimes "from the tin" (open on its side for months) the arc often goes soft and is prone to arc-blow. Soaking would mean say 1 minute with all the flux immersed in water (too long and the flux bloats and cracks - at several times longer than this "ideal" time). I've referred to this before on s.e.j.w., but never taken measurements - until now...
I observe that for all 6010's I have encountered, dipping the rod in water seems to have no detectable effect on welding performance.
The "Arcos Nu5" 6011 jumps +10V in arc voltage with the water treatment. That's a lot! And the effect when welding is unmissable. The rod will confidently lance a keyhole through a greater root face than the 1.6mm gap, 1.6mm root-face standard. And you can lean on it hard to force keyholing if weld prep. goes against you, etc (std. cellulosic root-run practice). No other electrode does this change. +10V is a lot of punch - a huge extra amount of focused arc power.
By the way - you can "drill" a plate of steel with the 6011 "Nu5" electrode wet, using any stick welding machine. It will happily "drill" a 12mm (half-inch) thick plate. [That is, put a plate of steel upright, strike the arc and press the rod in one place unmoving and the rod will steadily tunnel through the plate until it bursts through the other side and you can slide it further to break the arc, leaving your 2.5mm electrode seeming shot through the plate like an arrow through a target]
I think the arc voltage is proportional to "ferocity", in my opinion and that of the welding instructor who did these tests with me. So if you look at the voltage for the Bohler "Foxcel" 6010, you would come to the same conclusion we did. Tenuously, because neither of us are experienced with these rods - nodding respectfully to those of you who use these rods all day every day.
On the face of it, the "Arcos Nu5" 6011 becomes a super-performer when used wet. And it is the only electrode which does it. WHY is this? What is special?
Commercially, the effect would mean a thicker weld root, more able to take stress and leaving less volume of fill run to do (?). Advantageous if usable.
I'm figuratively putting on my soldier's helmet and ducking for cover here! Please be gentle with me, you folk who use pallet-loads of pipelining electrodes :~(
Richard Smith