Gunner wrote:
On Thu, 1 Sep 2005 00:35:55 +0000 (UTC), 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


Arc held too high above the work. It should be the same length as the
diameter of the rod core. see the narrow bead and the splatter?

The bead at the center bottom isnt bad.

Well, I could do much better than that bead with 6013 rods. I'll give up
on these old rods and buy some fresh ones.

Chris