Christopher Tidy wrote:
Gunner wrote:
On Wed, 31 Aug 2005 03:54:31 -0400, JohnM wrote:
Christopher Tidy wrote:
Hi,
Following our discussion about the strength of my two fillet welds,
I decided to put them to the test.
First I experimented with my technique a little. As Roy said that I
was using too much heat if the tip of the rod was red hot when I'd
finished a weld, I reduced the current from 145 amps to 115 amps
(the next setting down on my welding transformer). I had problems.
First the rod kept sticking to the work, then I had trouble keeping
the weld pool in contact with both the horizontal and vertical
surfaces. I had to weave up and down a little. And of course I ended
up with some slag inclusions, like this:
http://www.mythic-beasts.com/~cdt22/fillet_test01.jpg
After I while I thought I was getting used to working with less
heat, so I tried making some test pieces. I cut some 50 mm lengths
of 50 mm x 50 mm x 3 mm angle and welded them back-to-back:
http://www.mythic-beasts.com/~cdt22/fillet_test02.jpg
http://www.mythic-beasts.com/~cdt22/fillet_test03.jpg
I welded one using the drag rod technique (at 145 amps) and one
manipulating the rod by hand (at 115 amps). The one where I
manipulated the rod by hand ended up with a slag inclusion at the
start, but I decided to test their strength anyway:
http://www.mythic-beasts.com/~cdt22/fillet_test04.jpg
http://www.mythic-beasts.com/~cdt22/fillet_test05.jpg
I tested their strength by clamping one angle section in a vice,
then holding the other section in a mole wrench (vise grips if
you're American) and bending it back and forth. I counted the number
of complete cycles of bending each weld could stand before it broke:
http://www.mythic-beasts.com/~cdt22/fillet_test06.jpg
The first sample (welded using the drag rod technique) took 13
complete cycles to break it. When it broke, it was actually the
parent metal that broke rather than the weld:
http://www.mythic-beasts.com/~cdt22/fillet_test07.jpg
The second sample (welded manipulating the rod by hand) took just
one full cycle of bending to break it. This time it was the weld
that broke:
http://www.mythic-beasts.com/~cdt22/fillet_test08.jpg
I was a bit disappointed with this result, because apart from the
slag inclusion this weld looked okay, and I had hoped it would
perform better. So I made another test piece. This time I turned up
the current to 145 amps, and again manipulated the rod by hand. I
got a better looking weld without the slag inclusion. On the whole
it felt better welding at a higher current:
http://www.mythic-beasts.com/~cdt22/fillet_test09.jpg
This one took 6 complete cycles of bending to break, but again it
was the weld that failed:
http://www.mythic-beasts.com/~cdt22/fillet_test10.jpg
Although the test was crude, I think the result is pretty
conclusive. The drag rod weld is stronger, despite the fact that it
uses about half the amount of metal. It would also appear that the
penetration of the drag rod weld is better. The penetration of the
hand manipulated weld is pretty well zero, and it seems to have a
tiny slag inclusion at the root which can only be seen when the weld
is broken open.
I'm a bit discouraged because I can't seem to reproduce the drag rod
weld when manipulating the rod by hand. Even if I turn down the
current, I can't get the weld pool small enough, and I have problems
with slag inclusions. Maybe I need a rod with a thinner flux coating
which is more penetrating? Someone mentioned that 6013 is meant to
be used as a drag rod, and someone else said that 6013 gives pretty
bad problems with slag inclusions. Does anyone think I should try a
different rod, and if so, which one?
Any suggestions would be much appreciated.
Best wishes,
Chris
Definitely try a different rod. 7014 is also liable to give slag
inclusions, but not as bad as 6013. 6011 is much less likely to give
a slag inclusion, as is 7018. Assuming you have an AC only machine,
AC 7018 is available- I think it's a pretty friendly rod. If you've
got a DC machine, try some 6010.. with decent technique, there's
little problems with slag inclusions there.
Try some 6011 and 7018, I think you'll probably get along with them
better than the 6013.
John
6011 would be optimal. It digs DEEP. ..its 6010s slightly more
civilized brother, but its still an animal.
6013 is considered sheetmetal rod with limited penetration
You will also find that you WILL be turning your power down when
running 6011. I have perhaps 100lbs of 6011, and 5 lbs of 6013, as I
mostly run rusty salvaged metals.
Gunner
I looked in a box of odd electrodes I was given a few years back and
found some marked "ELGA P51/7018-1R". The core of these is about 2.5 mm
diameter, but with a thick flux coating they are roughly the same
overall diameter as my 3.25 mm core E6013 electrodes.
I tried welding with these and it was an unmitigated disaster. They
stick to the work really badly at 115 amps and pretty badly at 145 amps.
Often I destroyed the electrodes trying to tear them off the work. The
arc is very bright and hot (also noticeably green), yet it goes out very
easily. I found it extremely difficult to maintain an arc laying a
simple horizontal bead, or doing a drag rod fillet weld (despite the
fact that I found a website describing 7018 as a drag rod - maybe it was
wrong).
Now I think about it, I remember some guy at the welding store saying
that the "P" on the rods meant "low hydrogen", and that they were hard
to use. Is this true? There are also some rods marked "ELGA P45S/6013"
in the same box, but I haven't tried them.
From this brief experience I hate these rods, and I don't want to buy
any more! They seem very unfriendly and the fumes are disgusting, too.
Any thoughts? By the way, I'm using these on an AC machine.
Here are some pictures of my disaster:
http://www.mythic-beasts.com/~cdt22/fillet_test11.jpg
http://www.mythic-beasts.com/~cdt22/fillet_test12.jpg
http://www.mythic-beasts.com/~cdt22/fillet_test13.jpg
Best wishes,
Chris
You've probably got some DC rod there, the AC 7018 has added ingredients
in the flux to help maintain the arc.
Part of the trouble may also be that you've got some old rod that's
likely very humid.. go ahead and burn what you can, but buy some new rod
too so you can see how it really should run.
Don't give up on the 7018, when you get the hang of it it's miracle rod.
As Gunner states, you can cram the arc exceedingly short and that's a
major help sometimes.
Pick up some 6011 or 7014, try both of them. The 6011 will have a quite
harsh arc with a dry-looking puddle and fairly obvious slag while the
7014 will have a much smoother arc and puddle with a lot of slag that's
a bit harder to differentiate from the puddle.
The votech school I went to to learn to weld only offered 6013 to start
with, I found it fairly difficult to deal with.. got a job, started
running 7018, it was nice, nice, nice.. my favorite rod.
John