Shear grab repair

[mgarym]

Hi

As the title one of the teeth on my shear grab broke off,
what sort of rod should I be using to weld it back.
I assume the teeth are not just mild steel.

Thanks Gary

 

[HMB]

Teeth are probably hardox

 

[mgarym]

I see I asked about a repair on the same tooth that had a crack a few years ago
http://www.mig-welding.co.uk/forum/threads/what-rods.31616/
and I must have just welded up the crack with 6013's

 

[Bill Edwards]

You can't go wrong with a 312 dissimilar rod as they can weld just about anything and are the choice for unknown metals. They're also very strong. Expensive though!

I don't know about shear grabs, but digger bucket teeth usually weld just fine with 7018 - I have got away with 6013 many times over the years, but 7018 would be my choice if you aren't using dissimilar rods.

I've just read your previous post on this and the metal doesn't appear to be anything special. I'd choose 7018 if you have a DC welder or an oil cooled welder with a high voltage range.

 

[Welderpaul]

Don't weld excavator attachments/wear parts etc with stainless rods - it stops the next man burning them off again to replace.

 

[Bill Edwards]

Fair point for proper jobs. But there's plenty of old kit out there that'll never see certain parts replaced again as they will just get run until the rest of the machine has packed up, with buckets just being run to destruction.

 

[mgarym]

I have a parweld 160 inverter ,my oil cooled died a while ago,
so is the advice to use 7018 rods ?

thanks Gary

 

[Bill Edwards]

Yes, that's the best option.

 

[mgarym]

Any special setup for 7018 the tooth is 8mm tapering down to a cutting edge?

 

[Bill Edwards]

A picture paints a thousand words. Without knowing what sort of a joint it is onto the grab it's impossible to say what prep is needed.

Regardless of the setup though, it needs all the metal round the weld area to be cleaned properly with a grinder.

 

[mgarym]

Thanks Bill its just a butt weld so will give it a go today.

 

[Bill Edwards]

In that case grind a bevel (angle) off both parts so they taper and build/fill it up with a few runs.

Exactly like this:
http://www.mig-welding.co.uk/arc-flat-joints.htm

 

[mgarym]

Thanks for that

 

[mgarym]

Hi
Just to update,I couldn't get hold of 7018's on short notice
so went for 6013 3.2 and so far they seem to have done the job.
Thanks for everyones advice.

Gary

 

[Badger1bear]

Still no pics ?

 

[mgarym]

Sorry no pics my camera isn't playing ball at the moment.