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Welding dipper and boom

orville

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Joined
Jul 15, 2010
Messages
247
Location
Burnsville, Minnesota
Occupation
Millwright / weldor
When you weld on the dipper stick and boom is the correct welding rod 7018?
Is the dipper and Boom made of special steel, or is it just mild steel? I have seen some mention of AR steel on here, what is that?
Is the boom section always called boom or is there another name for it?

I have an old Batam that I want to re-paint and in cleaning up the sections I found one crack and some previous welds that who ever did them would not admit to. This Bantam is something most of you folks probably give to your toddlers to play in the sand box with. It is big enough to do what I need to do.
 

maddog

Senior Member
Joined
Apr 20, 2009
Messages
730
Location
middle TN
Hey Orville, I'm in the process of getting a Hein Werner{40,000lbs}, I did get a chance to get it running and even drove it abit. I like the old machinery, it puts a twinkle in the eye.

I've used 7018 for cast steel, but for mild steel I allways go for 6011. Maybe someone with more knowledge of your machine will be a bigger help?
 

daddy

Active Member
Joined
Jun 14, 2010
Messages
39
Location
usa
7018 will work fine, gouge the crack out and reweld.

Orville, I gotta agree with adam, and I'll add this: Get a fresh can of 7018. For critical welds old opened 7018 will have absorbed moisture from the air, and will be harder to light, and possibly more prone to cracking when you are done. Prep is 90% of good welding. Nice shiny gaps to fill, and burn it in hot.
 

John C.

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Jun 11, 2007
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Northwest
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Machinery & Equipment Appraiser
Most all excavator sticks and booms are made of mild steel. They go through so many load/unload cycles that if any harder they would crack right away. Even with mild steel they crack.

7018 welding rod is the standard of the industry. Using a new can is a good idea but not always possible. A lot of rod now days is sold in cardboard boxes. Most of the time you can bake out the moisture by just putting it in an oven for a couple of hours at 300 degrees.

I've also taken an old refrigerator and and stuck a 100 watt light bulb inside to keep the rod fresh. I keep sealable plastic containers for carrying the rod on the service trucks.

Good Luck!
 

powerjoke

Senior Member
Joined
Aug 2, 2009
Messages
1,125
Location
Missouri
Occupation
owner/operator/estimator/mechanic/grunt/ditchdigge
take it off, lay it flat and flux core it in HOTTT we've done it tons

Pj
 

orville

Well-Known Member
Joined
Jul 15, 2010
Messages
247
Location
Burnsville, Minnesota
Occupation
Millwright / weldor
take it off, lay it flat and flux core it in HOTTT we've done it tons

Pj

I don't have the facilities to take the dipper stick and boom apart and off. I don't have flux core either. Looks like I will be doing the dipper horizontal and the Boom in the overhead position.

This machine started its working career around Marshall, Minnesota. (Rich farming country) I bought it in Hibbing, Minnesota, Iron range territory. I think the tuff ground was too hard on the little machine.
 

SE-Ia Cowman

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Joined
Oct 22, 2009
Messages
240
Location
Iowa
Cracks

Drill a small 1/4'' hole at the end of the cracks this will help stop them from cracking again then weld the hole full. There is some high nickle rod available with 125000 lb tensil strength that has 35% ducktilty it is a little costly but a couple lbs would go a long ways. Mauer 909 super rod or Rockmount BrutisAAA
 

Cat Wrench

Well-Known Member
Joined
Mar 27, 2010
Messages
121
Location
Missouri
MG Industries 518 (their designation for 7018). MG is a little more expensive but it is a very good quality and it is very moisture resistant. It is a great choice to keep in a truck.

7018 will do probably 98% of all heavy equipment related welding.
 

daddy

Active Member
Joined
Jun 14, 2010
Messages
39
Location
usa
A pic of the crack may get you some more specific advice...


Drilling the ends is a very good suggestion, make sure you find the actual end.


Doing it "out of position" is strictly a matter of your skill level. If you are unsure of your ability, it may be worth the effort to take it apart in the long run. If you can weld your butt off, then go for it!

I like Hobart Bros. ( not the taiwanese tsc stuff) or lincoln excalibur myself.

If the section is all the same thickness, and relatively thin, you can probably just weld it, but it will not hurt to warm it up with a torch a bit, especially if the crack goes to a thick area or near a pin boss.

Good luck.
 

tonka

Senior Member
Joined
Jan 14, 2008
Messages
1,555
Location
Longview WA
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Equipment Operator
i would think fishplates over the said crack (after you weld that up) would be a good idea also...
 

alco

Senior Member
Joined
Apr 7, 2006
Messages
1,286
Location
here
7018 is just fine for what you will be doing. I would run a hot root pass with 6010 or 6011 and then fill and cap with 7018 myself. I've had people want 11018 used before, and we did it, but I think it's pointless as the tensile strength of the 11018 is so much higher than the plate they want welded. Now, using 11018 on high tensile plate, I absolutely agree with.
 

OneWelder

Senior Member
Joined
Apr 12, 2007
Messages
483
Location
Derry, New Hampshire
Running 7018 over 6010 /6011 MAY cause hard brittle weld. Anybody who has done this will probably have seen a yellow / gold look with flux that just about has to be ground off- this is an indication that that has turned hard.
A better way would be to use very small diameter 7018 rod for a root then go to a bigger rod if you want.
You could also make the crack big enough to in one spot slip a backing strip in behind- it can then be held in place by sticking a rod to it and holding till it is tacked. -
This would be a good method if you have several cracks running very close together
 

orville

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Joined
Jul 15, 2010
Messages
247
Location
Burnsville, Minnesota
Occupation
Millwright / weldor
That was one nice repair, has to be a little easier off the machine.

My crack is not near as bad as that one. It is in a plate on the under side of the boom up near where the dipper is pinned. It appears to be in the plate only, not in the boom section at all. The plate I would guess was put there so you would have to stretch it before you could break the boom. That is the only crack that I know of. I thought I should repair it now rather than later. What is the old saying an inch in time will save nine, or was that stitch?

I started burning electrodes back in 65 aboard one of those big gray yachts and have been doing it ever since. Not every day and all day long. I did pass a certification test for vertical up and overhead several years ago so I am not too worried about skill level. I will not knowingly buy jap or Chinese rods. Usually I buy Lincoln or esab approved rods. I have a Miller Legend that works real well to burn the electrodes. I do not have all the big shop space and hoisting equipment that some of you folks have or have access to so I try to do the best I can with what I have.

You folks have given me a lot of good suggestions and ideas and I appreciate that, Thanks
 

willie59

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Dec 21, 2008
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13,361
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Knoxville TN
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Service Manager
Given you have been welding for years, you probably already know this, but it bears repeating, if for nothing else to someone who is reading this thread who has less welding experience;

Keep ground clamp close to work area of component you are welding. :)
 

Swamp rat

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Joined
Apr 16, 2009
Messages
114
Location
La / Ga
Hello Orville , yhe project you are attempting is not hard,that was one of my repairs on the 220 hoe. Only thing to remember is - prep is the most important part of the job. If done two of these booms one weldes w/ 11018 rods and one with .045 fluxcore , both machines doing fine. Good luck
 

alco

Senior Member
Joined
Apr 7, 2006
Messages
1,286
Location
here
Running 7018 over 6010 /6011 MAY cause hard brittle weld. Anybody who has done this will probably have seen a yellow / gold look with flux that just about has to be ground off- this is an indication that that has turned hard.

I have never had that problem in thirteen years. In fact, many of the test pieces we had to prepare in school required that process. So maybe I got it figured out early and learned how not to turn a weld brittle.
 

orville

Well-Known Member
Joined
Jul 15, 2010
Messages
247
Location
Burnsville, Minnesota
Occupation
Millwright / weldor
Given you have been welding for years, you probably already know this, but it bears repeating, if for nothing else to someone who is reading this thread who has less welding experience;

Keep ground clamp close to work area of component you are welding. :)

On the dipper stick I did not see anything to ground to so I welded a tab to the stick and grounded to that. When I went to the boom section for something I forgot to move the ground, I did move it because I did not want to ground through the pin.

Here is some good advice if it was given 40 years ago. Back when everything had generators on the engine and someone did a repair to the machine or truck with an AC arc welding machine. After the repair the generator would not work because the AC machine de-ploarized the generator. I know of two people who had welding generators on trailers, they made a repair to the trailer with an AC machine and their welding generator would not work anymore. One of the guys had enough brains to gather up enough battery's and wire them in series and touch the wires to two places in or on the generator to get it to work again. The other guy still has an old P&H, maybe 30's vintage that will not weld anymore. That old P&H was powered by a V/8 engine that had a cool sounding fireing order. This happened to me with a generator on a 57 ford many years ago. Today I am sure this is useless informatiom. On machines with alternators which is all of them today you should remove your battery ground.
 

scholzee

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Joined
Sep 25, 2008
Messages
153
Location
Buffalo, NY
.

I've also taken an old refrigerator and and stuck a 100 watt light bulb inside to keep the rod fresh. I keep sealable plastic containers for carrying the rod on the service trucks.

Good Luck!

Yeah tried that but the light goes off when I close the door LOL !!!
 
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