How to 'repair' a worn cast iron bushing ?

[addertooth]

But nickel is so hard..

Nickel is not as hard as you imagine. It *is* very abrasion resistant. An American Nickel coin is alloyed with copper to enhance it's hardness.
On the MHO scale, it is actually softer than no-carbon Iron. It is only a bit harder than brass.

 

[seasicksteve]

Fabricate an appropriate cast iron bushing slip fit and use green lock tite sleeve retaining compound, I have done similar repairs with good results using this method

 

[woodchucker]

Nickel is not as hard as you imagine. It *is* very abrasion resistant. An American Nickel coin is alloyed with copper to enhance it's hardness.
On the MHO scale, it is actually softer than no-carbon Iron. It is only a bit harder than brass.

I had bought a taper attachment for my SB9. I didn't know it was cracked where the gib screws were. I had a welder nickel weld the cracks and fill the holes. I had a bear of a time drilling them out. Needless to say I have never mounted it. It's trash in my mind. I had a few bb's from the splatter on the opposite side, I was not able to knock them off. I had to take a diamond dremel cut off to remove them (and some iron)....

 

[dansawyer]

I think I may have identifified a reason the shoe was worn so badly. If the edge of the slot in the feed rod is slightly raised it will act like a cutting tool. Additionally when I place a 3/4 in rod in the shoe there is a lot of ware all around. The is little remaining surface that has not been worn.

 

[dansawyer]

Can a piece black cast pipe be used as a blank for a cast iron bushing?

 

[dansawyer]

Additional thought: There is no reason the bush can't have a half inch or so collar on each end. That would offer addtional surface support.

 

[Cadillac]

Nickel is not as hard as you imagine. It *is* very abrasion resistant. An American Nickel coin is alloyed with copper to enhance it's hardness.
On the MHO scale, it is actually softer than no-carbon Iron. It is only a bit harder than brass.

I don’t know about that?? Nickel is hard. We are not talking coins which are plated we are talking the element nickel. Which has gone through the roof!

 

[extropic]

Can a piece black cast pipe be used as a blank for a cast iron bushing?

No. Black iron pipe, in the size you're talking about, is not cast. It's wrought.

Recommended repair: First define the intended dimensional location of the bore from other features because after you add filler material, in the highly worn area, location will be much harder to find. I would fill the extreme wear area with braze filler. Then bore to press fit a high load sleeve bearing.
The advantage is that the bushing can easily be replaced in the future.

Steel shaft running on cast iron is the low cost design, not the best design.

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[addertooth]

I don’t know about that?? Nickel is hard. We are not talking coins which are plated we are talking the element nickel. Which has gone through the roof!

Nickel 4.0 on the Mho scale, Brass 3.5 on the Mho scale, Iron with no carbon is 4.5 on the Mho scale. You would build up the area with nickel welding rod, and then re-machine it. Nickel is VERY abrasion and corrosion resistant. Due to it's high abrasion resistance, it makes a great bearing surface as well. Farmers use this technique a lot on farming equipment where a shaft hole has been wallowed out. It is old-school, and effective.

 

[nnam]

While other suggestions are very good, I just wonder anyone entertain the idea of pouring babbitt bearing into it and bore it out. Maybe not strong enough in the long run? If I can heat the piece, I would just weld it. Then bore it up, and use a relatively thin bronze bushing so later it can be replaced.