Welding on Cat shear

[typ4]

We have a cat shear made by Verachtert, and need some crack welding procedures asap. Mainly filler material specs, 7018 rod, or what ever is required.
preheat,postheat so on, thanks.
It is cracking around the upper jaw pivot and across the inside of jaw.
Russ

 

[DirtHauler]

happen to have any zoomed out photos for referance? not sure what we are looking at there.

 

[typ4]

No zoomed out but it is the pivot area of the upper jaw. I will get oneup. It is in steilacoom come have a look.LOL

 

[John C.]

Don't know the company that you work for but you have a very big and technical welding job there. Have you contacted the local dealer for the shear yet?

 

[fast_st]

Yeah, looks like a technical weld, likely would need preheat to 200f, a big v groove and a lot of nice 7018 LH electrodes. This is the kind of shear used for demolition right, it snips beams into small chunks.

 

[typ4]

The local dealers didnt even know CAt had a shear. We contacted the guy we got it from and he put me in touch with the Genesis repair facility and they gave some very good info. 10-4 on the 7018, preheat to 350 to 400 f , and it is a demolition shear,


Here is our other shear, I dont think I am welding this one back on


http://www.oilburners.net/forums/showthread.php?t=44030

 

[norite]

Don't know what grade of steel it is but it must be tough stuff. Maybe 8018 to 10018 rod for this job is required. Perhaps some kind of alloy? You need to find out what this thing is made of before you can come up with a repair procedure.

 

[typ4]

Yep, that is the plan. I may be taking a sample to a metallurgist I know if I cant find out.

 

[motrack]

wow..... tore up another shear! That job is becoming expensive.

You need to find some better operators.

 

[fast_st]

It'd be a bigger job than I could tackle for sure but my guess is you'd want to xray or gouge out that crack to the bottom then start welding from there, It looks as if it has been surface welded a few times and the cracks appeared at the stop points. The mfg might be able to tell you what alloy steel it is, to guide proper electrode selection.

 

[catmtl]

I dont know who you spoke with at NC (cat dealer) But I would be happy to look at it and give you some options for repair. I have worked with CAT shears before.

Jeff H
PSSR
NC Machinery Co.
206 261-0002 cell

 

[adam21584]

Grinding out the crack will tell you a little about how hard the metal is. mild steel will grind with sparks going a long ways and yellow. harder plate sparks are more red, and don't travel as far. 7018 or 10018 should be fine, for about anything repair wise. Air arc would gouge out the crack allot faster and cleaner.

 

[loggah]

I have a old Labounty msd 220 on my cat 235, the labounty shear is fabricated out of T1 steel ,any buildup welding or repair the factory says to preheat to 300-400 degrees and use 7018 rod ,i know its not a cat shear but it could be similar. Don

 

[typ4]

Well my good friend Dan is up here and he is a very experienced welder and he torch scarfed it out, ground it and did the preheat, welded it up with dualshield wire of the recommended alloy and it has ran for a week , so far so good. All the welding done by the PO was very poor.
Thanks for all the great info. I will keep posted, we are winding down on the job so hope it makes it to the end.

 

[DirtHauler]

Happen to get any pics of the repairs in progress or of the finished product. I have not worked with shears at all and am just curious. My first impression from the photos of the cracks ment a total loss for the shear. That is why i love this site, learn new things everyday. Now if only i could convince other people i work with that i am not just a stupid know it all truck driver... Well maybe they have a point on sometimes

 

[typ4]

No he did it on the weekend while I was home, we kinda rotate so one of us is here all the time. We figure th ere is nothing to lose if its cracked and we weld it, it may fail but if it buys some time then that is money not spent.

 

[Deeretime]

IMO 6010 Root then 7024 only good if you can get the shear flat tho, no good for upper hand. Take some pictures of it when its done!

 

[hvy 1ton]

Well my good friend Dan is up here and he is a very experienced welder and he torch scarfed it out, ground it and did the preheat, welded it up with dualshield wire of the recommended alloy and it has ran for a week , so far so good. All the welding done by the PO was very poor.
Thanks for all the great info. I will keep posted, we are winding down on the job so hope it makes it to the end.

Gotta love dual shield, you can really lay down some metal with it. It's right up there with 6011 for being able to weld 2x4 back together too.

 

[Lee-online]

I know its a little too late but I just stumbled onto a procedure to repair the large B series demolition and scrap shears.


(1) Weld cracking may occur at the housing/hub transition.





Fabricate the Reinforcement Plate

Fabricate two reinforcement plates from an Alloy Heat Treated Structural Steel that meets ASTM A514 or equivalent material. Refer to Illustrations 2, 3, and 4 for plate dimensions.

*I did not add the Illustrations.

Weld Repair and Rework Procedure
Follow the instructions for pre-heat, inter-pass, and cooldown requirements.


If necessary, gouge out any existing weld cracks down to the dowel hole.

Preare the area for repair welding.
The housing and hub material must be preheated to 150° to 175°C (302° to 315°F). Preheat an area extending at least 203 mm (8 inch) beyond the area to be repair welded. Weld inter-pass temperatures should be 125° to 175°C (257° to 315°F). Do not weld in ambient temperatures below 15° C (59° F)

If necessary, make the repair weld root pass at the top of the dowel hole and ensure uniform penetration and bean consistency.

Locate the reinforcement plate (2). the plate should be located on the hub with the edge of the plate 20 mm (0.79 inch) from the edge of the housing shown in Illustration 3. The weld should not contact the hub nut guard (small piece on the outside of the hub). The weld cannot penetrate the outside weld or the hub nut guard. Refer to 4.


Place a 12 mm (0.47 inch) fillet weld all around the reinforcement plate. The recommended penetration is 1.5 mm (0.059 inch) minimum.

Cover the repair area with welding blanket and allow weld to cool to ambient temperature.
Note: Area must not cool more than 50° C (120° F) per hour.


Repeat Steps 1 through 8 on opposite side of shear.

 

[typ4]

If you have those pics for the plate that would be good.

Thanks for that info. I think that may have been done, The crack we had was on the upper jaw to hub-pivot area.

It has not cracked since and has more time on it than it did before the crack.