Fillet weld strength testing

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:
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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:
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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:
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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:
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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:
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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:
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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:
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This one took 6 complete cycles of bending to break, but again it was
the weld that failed:
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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
Reply to
Christopher Tidy
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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
Reply to
JohnM
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
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
Reply to
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:
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Best wishes,
Chris
Reply to
Christopher Tidy
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.
same " stub saver" stinger I have. Works well
Looks like wet or very old rod and run too hot
Based on your descriptions..it sounds to me like you are trying to carry the arc much too high above the work. Get down into it once you have the arc started. Drag the tip of the arc nearly in the puddle..arc length should be no more than the diamter of the rods core. With the 70xx series rods..I actually am down inside the puddle on the leading edge and it welds marvelously.
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
Reply to
Gunner
Most 7018 should be run DCEP, however there is 7018 made for AC but it doesn't look like you have that kind. I think your problem may be elsewhere as well, but it surely is also that your machine is AC.
Where do you live? I have a nice little AC/DC buzzbox I can let go dirt cheap.
GWE
Gunner wrote:
Reply to
Grant Erwin
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
Reply to
JohnM
England I'm afraid - I think the shipping would be a bit high! Thanks for the offer, though.
Chris
Reply to
Christopher Tidy
Very likely both are problems. These rods were free and are close to 10 years old.
I tried to reduce the arc length as much as I could, but it still kept going out. I'm convinced there is something other than my technique wrong here. I'm doubtful anyone could make a decent weld the way those rods were behaving. Something felt very wrong.
Thanks for the advice,
Chris
Reply to
Christopher Tidy
I tried really hard to get a short arc. I thought this was the problem too, so I put the tip of the arc nearly in the puddle, like you suggest. For those welds in the picture the arc length was less than the diameter of the core. The arc still kept going out and giving me major spatter. I've suffered the "pigeon crap" situation due to an excessively long arc in the past, and this definitely isn't the problem here. Normally I would be able to lay a decent looking horizontal bead (even if my fillets aren't perfect yet), but this time I just couldn't do it. Something felt very wrong.
So it looks like I should buy some more rods. Out of 6011, 7014 and 7018, which is most friendly and best suited to welding sections? I want something which gives fewer problems with slag inclusions than 6013.
Best wishes,
Chris
Reply to
Christopher Tidy
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
Reply to
Christopher Tidy
As others have said, use E6011/E4111 rods for a root run if full root penetration is important. I basically hardly ever use anything else. Yesterday I used a 1/8" E4111 rod to 'tack' weld 1mm thick metal while repairing a broken handle on a cheap pressed metal spade. You need good hand-eye coord for that, tho, otherwise you have a hole.
But hey, it was faster than dragging out the MIG gun.....
PDW
Reply to
Peter Wiley
Your old rod probably needs the flux dried. 24 hours at 450 degrees will drive off the adsorbed moisture and cut down the sputtering. Bugs
Reply to
Bugs
Go to your local welding place and get a pound of 6011 and try it. Im concerned about your statement that the arc extinguishes though. Does the sound of the welder change drasticly when this happens? Im wondering if you may not have a wire or contact that opens under load.
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
Reply to
Gunner
Your rod might be wet. 7018 requires storage in an oven, with reheating to 700 F or something like that to dry it out. The flux is hygroscopic, and if it gets wet flakes off and welds like crap. It also has to be bone dry to be low hydrogen.
Pete Keillor
Reply to
Pete Keillor
scroll, you know.
Tim
-- Deep Fryer: a very philosophical monk. Website:
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Reply to
Tim Williams
Sounds just like the problem. The flux does flake off and they do weld like crap. Although these rods are currently stored in the house, I don't know their history. They might have got damp at some point.
Chris
Reply to
Christopher Tidy
Looks like 6011 is what I need. I don't think I'll go for 7018 as I don't have a rod oven and don't want to have to get one right now. I need a rod that works on AC, too.
I'll probably buy more than a pound as it's a fair trip to the welding supply store. A 5 kg box of 6013 was about £10 when I bought one last year.
Thanks to everyone for their advice.
Chris
Reply to
Christopher Tidy
I can't find my chart, but 700 seems way to high. IIRC it is in the 4's or 5's. I did all of mine in the B-BQ then vacusealed. Some broke, but a new oven is in the works once I get my surface grinders up and running.
I have some nice small burner size cal-rods - electric stove - and likely I can figure out something nice for one or both I have. I can buy more...
Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder
Christ>
Reply to
Martin H. Eastburn
Actually..you really dont need a rod oven for 70xx series rod, unless you are doing actual life safety types of stuff where you need ZERO hydrogen issues.
As long as its mostly dry..it welds (for me) just hunky dorey. I did buy some rod from Harbor Freight once in a pinch..Chinese welding rod. And it sucked with large slurppy sounds. I finally tossed 10lbs of rod straight into the shit can in disgust. While Im not a "weldor", I can generally stick a couple pieces of metal together well enough most of the time and that stuff was utter trash.
I was browsing Ebay, using my local area as base of search and found a clearance company that had some cans of Fleetweld in, 50lb cans that no one was bidding on, simply because of the shipping weight and they had some negative feedback. I dropped em an email asked if local pickup was ok, and when they agreed, I bid and won a can. for $10USD.
When I showed up to pay and pick, I offered them a sum for every can they had..about 16 of them. They hemmed and hawed..and finally agreed so I went home with 800lbs of Lincoln Fleetweld in sealed cans, sold them all except for a couple to my buddies and then spent the next couple years burning them up.
Recently, I was in a clients shop and mentioned to one of the maint workers that I was dabbling in welding. He perked up, and said "wait here"..then split for a few minutes. He came back, asked me if Id take $40 off my bill in trade for some :"welding stuff". Seems they had a company policy change, would only allow certified outside welders do their welding maint work..and had this "old welder" and " some rod" that were surplus and I could buy it for that $40 discount.
It turned out to be a Miller Dialarc 250 (marked Airco Bumblebee) and another 400 lbs or so of rod...of all kinds. Exotic and common stuff. Stainless steel rod, hard facing cast iron rods, aluminum rod, nickle rods and on and on....I gave the welder to a buddy, and kept the rod. Some fascinating stuff in there... Ive got a half dozen 5 lbs boxes of a coated rod, black in color with a number Ive not been able to cross reference...I think its stainless..but it wont rust, will make absoultly beautiful welds no matter how badly I treat it and will stick anything that has steel or iron anywhere in it, together. I save it for special occasions . The stuff is like using a hot glue gun.
Buy or beg a pound of 6011, and try it out. If you were in my neck of the woods, Id give ya some. (California)
Im 'long term" loaning out my Lincoln Tig 250/250 to a friend this weekend, I need the room..shrug and Im starting to figure out the Airco 300 amp square wave tig machine..finally able to weld aluminum after replacing the breaker with a 60 amp one that wasnt 20 yrs old.
Good luck and let us know how the 6011 works out.
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
Reply to
Gunner

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