Cracked weld

I was trying to weld some angle iron onto my trailer and I thought I was doing a good job but then the weld cracked right after it cooled. What did I do wrong? I'm using a 100 amp arc welder and 6013 rods.. Is it possible when it cooled the angle iron contracted and split the weld?

The most likely suspect is that one piece or the other (of the two pieces you were welding together) was high carbon steel. The other possibility is that it was hydrogen embrittlement, and maybe you should try 7018 rod, which is low-hydrogen.

Or maybe you just goofed up the weld.

Grind it out and try again.

Grant

--Could be unequal cooling rates along the length of the weld; how long a piece are you welding on? Best way to do this sort of thing (I'm told; no expert me...) is to do several short lengths of weld, spaced out along the piece, then follow up by welding inbetween these, etc.

Or lead. But this will make little visible bubbles, besides the obvious crack. Does angle iron exist that contains lead? Never seen one.

Nick

_Lots_ of rust not beeing removed before welding?

Nick

"Michael Shaffer" wrote: (clip) the weld cracked right after it cooled. What did I do wrong? (clip) ^^^^^^^^^^^^^ I think we can assume the trailer was built out of good material, but was the part YOU supplied bed rail, by any chance? That stuff is not controlled, but it is generally very hard, so that it won't sag, which means that it is possible for you to wind up with a brittle weld. (ESPECIALLY if you cool it with water afterwards to save time.)

Yep, it's bed rail.

Get rid of that 6013, which is designed for sheet metal, and use a real rod, like a 7018.

Steve

Say no more!

Was the crack in the same direction of the weld, or across the weld? Was the crack right down the center of the bead, toward the edge of the weld, in the base metal itself? How many passes? How thick?

I have recently experienced some cracking in my welds as well. I was using 7018 rods to weld mild steel pivot supports on a forklift carriage to attach it to my tractors front end loader. After a bit of googling to get some idea as to why,I read that 7018 rods cannot be exposed to the atmosphere for more than four hours before absorbing too much moisture. I ended up using 6010 rods.

stan

"stanley baer" wrote

In the oilfield, 6010 is called "mud rod" because it will weld in such adverse conditions. If you look at 6010, you will see the coating is a LOT thinner than the 7018, which doesn't allow it to absorb nearly as much water. 6010 is a great all purpose rod for cutting through galvanize, rust, mud, dirt, scale, anything to get weld metal on the base metal.

Steve

I had a good idea that this was old bed frame (OBF) as soon as I saw the subject line. You're fortunate that you discovered the problem before the trailer was taken out on the roadways.

If OBF could be reliably welded, the frame manufacturers would weld on those legs and headboard brackets.

Welded OBF isn't trustworthy for bearing loads. Overhead storage shelf brackets, vehicle/trailer accessories/brackets subjected to shock loads, stairs, ladders, safety rails/bannister brackets (etc) should all be avoided.

I've had welds completely pull out, all the way down to the root of the penetration, when I've intentionally separated welded OBF parts. The same welds in mild steel can't be separated using the same methods.

WB ..............

Another reason to avoid old bed rails: when you start to drill a hole or make a saw cut, you can't be sure you will be able to finish it. One hole may drill fine, and one right next to it will just dull the drill.

Bed rail is great for dulling drill bits on, for replacing grape stakes and for the odd bit of misc shelving and what not..but for anything serious..or being welded to material other than itself...

Shrug..been there, done that...

Gunner

"Considering the events of recent years, the world has a long way to go to regain its credibility and reputation with the US." unknown

6010 rod will weld wet. It will weld under water. I've seen it done. The coating on 6010 is way different than 7018. It is a cellulose based coating. ISTR 7018 has iron powder in it. ERS

Correctomundo! I personally have used 6010 to "weld" underwater. You can achieve up to 80% strength, but only 50% ductility because of the quenching action of the water. We once used some hard facing rods underwater, but that was only to run beads on two pieces of pipe that were to be clamped together so that they would dig into each other to have a balanced galvanic reaction.

XX18 rods can have up to 25% iron powder coating.

Steve

So I guess the duty cycle of the welder will be the 30 seconds or so that you can hold your breath??? Ken.