Having to do butt joint test pieces using 2.5mm 6011's for a root run
in 6mm (1/4") mild steel plates bevelled 60 deg included angle. Root
gap is 2.5mm and root face about 2mm.
If I set the current to a 60amp @ 80v ocv starting the rod is VERY
painful, but eventually it runs ok, but I get all sorts of inclusions
from the false starts. If I go just over 65a to get a decent start I
burn nice keyholes in the root run.
Any tricks I can apply apart from bribing the inspector?
I'm limited to using a straight transformer AC welder so no foot pedal
If I do the same runs in a 6013 rod they come out beautifully but 6013
aren't allowed :(
For 1/8" 6011, I will usually run at least 85-90 amps DC, so I suggest
that the amperage is too low. Starting is not a problem.
For the burnthrough, 6011 has much more penetration than 6013.
The electrode is 2.5 mm and the root gap is the same size. Since it's
beveled, the metal is thin as well. For 1/4" plate with the
penetration of 6011, push the test pieces together, then open the gap
to a hairline separation. All that heat has to dissipate somewhere.
What tip manipulation are you using? Are you pushing or dragging along
the weld seam? What is the angle of the electrode to the surface of
the plate? Are you using a stepping motion?
6013 is a contact rod that can be dragged along the metal surface.
6011 is not a contact rod. What arc length are you holding? How big is
These factors, including travel speed, affect the amount of heat fed
into the joint.
I would be using a bit more amperage.
The trick to these is to spend time preparing your test pieces. I am
guessing the bevel is done with a torch cut then cleaned with a grinder or
better yet a belt ginder. After cleaning the edge whould be draw filed and
checked with a straight edge. the land should be consistent and you should
see no light under the straight edge put on the land. You can check your
two pieces to make sure they go together light tight.
Set your gap and tack weld one end then the other. Run your finger
across the back. The plates should be even. If one plate is higher then
your root bead will lose its tie in on one side. The tacks should be 3/4
inch long. Any shorter and they will shrink as you run your root.
I like a bit tighter gap and thinner land but each to his own. You want
the gap so that the rod will not fit through cold. If you get it right you
can ride the tip in the bottom of the root. You will see little of the arc
as the root is filled. If the joint opens up into a full keyhole then you
have to slightly whip forward on each side to dissipate the heat.
As near-beginner, can comment:
Know good AC machine (oil-cooled "Oxford" arc-welder in UK) and 6011's
keyhole the root beautifully. Bit offputting at first hearing
mains-frequency crackle (unlike continuous sound when DC welding with
same rod), but look and you see the joint is just fine - and it feels
just the same to handle during welding (to my limited experience!).
70A recommended max. for all 2.5mm cellulosic - xx10 and xx11 (???)
Recall slightly higher amp setting selected when doing AC 6011
keyholing compared to exactly same rod used on DC welding set.
If current too high, cellulose starts to char on length of rod before
getting into arc, degrading the shielding and arc penetrating power.
Shouldn't tell you this - found can go to 80A DC if soaked rods in
water before use, then get stonking great penetration due to higher
current, more hydrogen(?) and better-preserved cellulose going into arc
(?) - but don't do this on a "coded" job!!!
My more extensive thoughts, released as "derranged insomniac musings on
You are pushing the rod into the root of the joint and getting the
Andrew Maws> Having to do butt joint test pieces using 2.5mm 6011's for a root run
If the rod is sticking a lot, either your current is too low or your
technique is lacking. I assume you are using the appropriate whipping
technique for this kind of rod and know how to strike an arc. So I will
concentrate on current.
Manufacturer's recommendations for 6011 I use is for 50 to 85 A for 3/32"
(2.4 mm). So 65 A is right in the ballpark unless the procedure you are
qualifying to doesn't allow it. FWIW current required with AC is higher
than with DC. Also note that the specified amperage is at the electrode.
What you think you set at the control may not be what you get at the
electrode because of calibration issues with the control. The only way to
know is to clamp a meter around the welding lead.
Also be aware that different manufacturers' 6011, and even different
versions of 6011 from the same manufacturer, exhibit markedly different
operating characteristics. One may run happily at 60A and another may not
run well until you give it at least 70A.