View Full Version : Digger Bucket
04-04-2008, 09:03 AM
Can anyone tell me what grade steel digger buckets are made of. And what flux core wire to use too.
04-04-2008, 10:12 AM
i would tend to think that it would vary between MFR's and even models/serial numbers on the machines... go any other information on the unit?
04-04-2008, 07:01 PM
Excavator, backhoe, loader? what type of bucket. Most I have dealt with used AR plate. Not sure I can help you with the wire, as most of my work is more with stick. If it is AR plate a low hydrogen rod is used. However since wire is a low hydrogen process. I have repaired a few back hoe buckets with just plain old 70s-6 solid wire. The type of bucket, and just what you have to do to it would help in giving correct advice.
04-04-2008, 09:27 PM
It is an excavator bucket. The deal is, with teaching apprentices we are going down the route of project based delivery at the Tech where I teach.
I have been talking to one of the local contractors and he will provide all the material including consumables and the apprentices will make a bucket for him.
From their point each project will include various skills which will marked off against their footprint. For example, making patterns for profile cutter, so many points, using profile cutter, so many points off another subject, machining bushes, another subject and so on.
This is a project that he would normally not get done so no one in the local economy is missing out. The apprentices get to use their skills on a project they might never otherwise see.
I have got some information from Caterpillar but have not had much luck in tracking down this part of the project.
I have seen them made or repaired with mild steel but the wear factor makes me lean towards bisalloy or corten plate.
04-05-2008, 12:48 AM
If it is an excavator I would go with AR500 but be prepared to sit down when you pride it.
04-05-2008, 01:44 AM
We have esco lips on our buckets 5500 hitachi and they are t-1 I have the astm number at work. which crack repair or installation requires 7018 or its equivelant in low hy wire, We use lincoln dual shield 71-elite with 75/25 shielding gas. If you contact esco they are really good about giving weld info for the product they produce. If your not in too much of a hurry 6 days from now I could get the filee I have on complete bucket including the above info. The reason I'm not giving anymore info is the standard used by hitachi is different then astm which I'm more familiar with. So let me know.
04-05-2008, 02:33 AM
Thanks, 6 Days is great, we are about to take a term break (half way through the first semester). During the break I will be taking a group from industry who want to upgrade their welding skills so no apprentices for the next 3 weeks which will give me time to prepare.
04-05-2008, 06:10 AM
Indoors, use dualshield.
Outdoors, use NR-232 innershield.
It's been a couple of years since we had an excavator bucket built for the machine at work, small 15,000 lb machine. At the time I wasn't welding seriously but did ask a few general questions to the guy who was fabing the bucket. I asked about special steel, and was told the majority of the bucket was mild steel. T1 or AR was used in the side cutters, front floor, and strapping accross the back of the floor. This would reduce weight and give replaceable wear surfaces. Don't know if this is of any value, but its what I remember.
What does he plan to use the bucket for, and what type of soil does he usually dig in? The reason I ask is we have 4 buckets for our machine. We have a 36" bucket that is the one that was custom built. This is the one that is almost always on the machine. We got a used 12" bucket, that is only used for 12" footings that are required by 1 customer. The other two, 18" and 24" came with the machine and are almost never used unless we have a lot of trench that sise to dig for footings. Wear on anything but our 3' bucket is negligable at best, most jobs don't even wear the rust off the parts. If this is the case with this guy, just using AR or T1 on wear critical areas may work well. As far as soil. I know when we dig in Jersey in the sand by lunch you can almost see yourself in the polish on the bucket starting with a rusty bucket. I never see that around here in the clay, rock, mud mix we have. BTW true rock buckets are different altogether. From what I understand they are designed to break rather than tear the machine apart.
04-05-2008, 11:05 AM
Here's a little info from aws d1.1 welding code:
5.12.1 MAXIMUM WIND VELOCITY. GMAW, GTAW, EGW, OR FCAW-G shall not be done in a draft or wind unless the weld is protected by a shelter. Such shelter shall be of material and shape appropriate to reduce wind velocity in the vicinity of the weld to a maximum of five miles per hour (eight kilometers per hour).
I'm sure you ment well but as you can see it is exceptable provided the above information is utilized correctly.
04-05-2008, 11:15 AM
Clive here is a link to esco
04-05-2008, 08:55 PM
All of the excavator and backhoe buckets I have worked on were repaired with 7018 and 7024. Only the teeth were hardened. Some had replaceable wear bars some didn't. The last was a Komatsu that they split down the middle. The front section is cast steel with the remainder mild steel. I used a 6010 root pass then completed it with 7018 (had to as it was all uphill). I vee'd out from both sides with a scarfing tip and then used a grinder for the fine work. The reason I went into all that is coming now. Three days later they brought it back with two splits in the bucket (not in my weld but probably due to it not failing) approximately halfway out from the center on each side. I used the same method on it and it is still being used. I did leave out that I preheated and post heated due to the cast steel piece. I don't know if that is an absolute necessity but I have used the method in the past joining cast steel to mild steel in heavy industrial applications with good results. I have built backhoe buckets used in hard rock work in the past using mild steel and welded with 7018 and never got any of them back. Since all came with a warranty if there had been any failures then I am sure I would have known about it.
04-05-2008, 10:22 PM
At the operation I work at we have (1) 2500 ,(2) 3500 and (1) 5500 hitachi hyd shovels.
4 992 and 1 994 cat loaders, The manufacturer specifically states on every single machine mentioned above to weld with only 70 series rods and wires! It is taboo to utilize 6010 since it does not have the desired characteristics for the base metal in the buckets.preheat and post heat will make all the difference for a successful repair.
04-05-2008, 11:04 PM
Thanks for your input, I have decided to make it in in mild steel, we use 70XX rods and wires as standard in mining anyway. The lip and wear plates are already solved, having been provided by the contractor.
The soil is called pindan and is like a sand that has iron ore in it, it packs so hard that a spade will just bounce off. But if you want to dig it you put a garden hose on a length of 1/2" copper pipe and just lance into the ground, then it's like digging wet sand. It is hard on earthmoving equipment, but fortunately we don't have many rocks unless you go very deep.
We will use the hardfacing that the contractor supplies.
I am going to start drawing it up this week. We are copying an existing shape but narrowing it so I'll just make a template of the sides and then work out radius' and degrees from that so the boys can lay it out properly. We might have to roll the bottom rather than use the brake press as the laser died during the week and as it's 20 years old parts are hard to come by. We could bypass the lasers but that would compromise safety so it's a no go.
I'll take shots of it during construction so I can post.
04-11-2008, 12:32 AM
Clive here you go!
04-11-2008, 12:36 AM
04-13-2008, 09:20 AM
Thanks I hadn't had a chance to get back to check on it. Have had a change of plan, the plate is Bisplate 80 and the contractor has most of it in his yard already, I have taken some shots of his existing bucket and drawn up a plan, I will scan it and when it is underway post it.
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