Welding broken loader bucket cutting edge

[Sebculb]

Hola Everybody!


So When I got this hoe it looked like the cutting edge had never been turned around in it's 21 year existence. The bottom edge of the loader bucket was literally about an inch thick. So I cut it off and turned it around for a fresh new edge. My mechanic told me not to use 1/2" bolts from the corner hardware store that they'd break right away. I'm impatient and cheap, so I did use those bolts instead of getting proper ones. Figured if I tack welded the blade to the bucket strategically it'd help.

Anyways, doing a rocky job today I lost the right end of the blade where the end bolt broke, broke about a foot or so off of the cutting edge. Should've listened to my mechanic. So now i get to weld it together again. I guess the questions are:

What welding stick? 6013 is almost the only one available here in the jungle, although stainless steel sticks can be found at some of the bigger hardware stores. If I drive 40 minutes i might be able to find some other sticks. Almost all my experience is with 6013 for general construction. Would the stainless steel work better on the cutting edge? I imagine it's some type of hardened steel.

The rest of the blade is tack welded to the bucket, and the bolts are tack welded to keep them from loosening. In addition to being cheap and impatient i'm also lazy (waaay busy) so I don't want to take the whole thing off if I can avoid it. Is it foolhardy to just weld it together from one side? Grind out a good V and run with it? It's going to get hot too, the piece is about 3/4" thick and 6" wide or so. Would welding a series of increasingly wider beads get hot enough to affect the temper of the bucket? I guess I could just let it cool for a while between passes but it'll take a long time.

Anything else I'm missing here? planning on tack welding the blade to the bucket a little better, to compensate the inadequate bolts. I'll try not to let the bucket get too hot, I've welded a lot of damage on the bucket already anyway. Getting proper bolts is a pain in the butt. They'll be expensive (easily $50) and I'd have to wait. of course, how much does a new cutting edge cost in the jungle?? '97 JD 310D backhoe, the piece of metal is about 7'x6"x3/4" steel, probably hardened.

Thanks for any advice or insight!

Sebastian

 

[3Ts]

Since you've done welding before you know what happens when you get a piece of steel hot. Those Heat affected zones are important to watch out for. And if it is hardened, the welding will affect the hardness and temper. There is a reason the cutting edge is bolted to the bucket and that's because it's considered a wear item to be replaced. I don't see why you can't weld the "replaceable" cutting edge to the bucket, but then it's no longer replaceable without a whole lot of work. Personally, I would stay with the bolts.

 

[Sebculb]

Thanks 3T's perhaps it is better to weld it in it's totality. Thinking about it more if I was ever worried about losing the temper in the loader bucket that went out the window when I filled in a bunch of gaping holes that came with it with a lot of 1/8 6013. Should've probably patched it but just used more chewing gum. Sooo, it may be better to just run a thin bead across the whole front edge and avoid having stress points that tacks would cause. Thin bead to try to keep the heat down. Proper bolts are a special order chasing around kinda thing here and I gotta have this thing working tomorrow or definitely wednesday

No idea how much a cutting edge costs, but I imagine easily $2-300 and whatever it's supposed to cost it'll cost double here. Trying to keep the "replaceable" concept far away, just the thought turns my stomach.

What is the pre-heating concept? does that keep the temper, or prevent brittleness, or increase penetration or what?

Thanks!

 

[RNeumann]

Since you've done welding before you know what happens when you get a piece of steel hot. Those Heat affected zones are important to watch out for. And if it is hardened, the welding will affect the hardness and temper. There is a reason the cutting edge is bolted to the bucket and that's because it's considered a wear item to be replaced. I don't see why you can't weld the "replaceable" cutting edge to the bucket, but then it's no longer replaceable without a whole lot of work. Personally, I would stay with the bolts.

Yep we are just adding bubblegum to the bailing wire! With that said necessity is the mother of all inventions. The material thickness will require you to make bevels so when the two pieces are together it makes a “V”. The rod is out of my pay grade but I’m assuming if you won’t use the proper bolts you aren’t going to let the proper welding rod slow you down. With that, let it rip with 6013- multipass.

 

[3Ts]

Since it has to be operational in a day or two and the proper solution takes longer than that - Oh well, I would do what ever I have to do to get it working and worry about "the right thing" later. Since you have 6013 and have used it before, I agree with RNeumann - 6013 and multipass.

 

[3Ts]

What is the pre-heating concept? does that keep the temper, or prevent brittleness, or increase penetration or what?

I don't understand this question. Where did that come from? If it's from my "Heat affected zone" that has nothing to do with pre-heating, but rather the effect the welding heat has on distorting a piece of metal. Heated metal expands. If you heat one side more than the other the one with more heat will expand more and cause the metal to distort. This will be most obvious if you run a continuous bead the length of the cutting edge. You will not like the results. However, I've never welded steel as thick as you are dealing with so I'm not sure if it will be as much of an issue as it would be with thinner stock.

 

[Sebculb]

So then why is it recommended to preheat complicated welds sometimes?

 

[GLyford]

Okay, not had to do much of this, but I think I can hit the highlights:

It can sometimes help keep things from warping or doing other weird things that happen if one thing cools faster or slower than something else you have just attached it to, if everything cools down together instead.

If the steel is hardened, cooling too fast can sometimes make it so hard it will be brittle. Sometimes so brittle that just cooling down fast will break it. Heating it first can help keep it from cooling too fast. Another thing people will sometimes do is weld only small amounts, not much more than a tack, then let it cool completely to where you can touch it with your bare hand before starting again. And even then, skip around, so you basically have a bunch of little sections that eventually connect together. Very time consuming...but you don't have to heat anything first.

So rather than all that waiting, some people heat everything and then weld everything up at once. Then let it all cool slowly together, either with a torch on it that they keep moving further away, over several hours, or with a welding blanket or piece of house insulation...at least they can be doing something else while it is slowly cooling.

If you only have access to a small welder and will have to take a bunch of breaks anyway...skip around. Don't keep welding in the same spot. That will at least help.

 

[k0ua]

And 6013 is about the last rod I would use to repair something like that. It is ok to fill holes in the bucket, but I sure would use 7018 for that edge. IF I was going to weld it, and I understand you are in the jungle, and cant just run down to tractor supply in 5 minutes and get a tube of 7018. BUT in my mind it would be worth a two hour trip.

 

[bigdeano]

I welded an old grader blade on my loader bucket 30 years ago. I used 308L stainless rod because it's resistant to cracking. I understand 312 might be better. The weld is like new, not a single crack. If all you have is 6013 you could try preheating the cutting edge and trying it, but it will probably crack, because the cutting edges are high carbon steel.