Early yoke welding

fiatfan · Dec 3, 2020

So I have this lower yoke from an Atlas or early Commando, and some PO have drilled holes in it. I was going to weld them but wonder if they are made of some cast iron and it would require some special welding equipment, or is it steel? I have a standard MIG machine.

kommando · Dec 4, 2020

Malleable cast iron would be a possibility, used on footrests, centre stands, frame lugs etc. The item is cast iron but then heated for hours to drive out the carbon until the carbon level is the same as steel. The cast iron then takes the physical properties of steel so will bend instead of cracking. It will take a weld but risks creating a weak area, I would tap the holes for grub screws and then if you want a smooth surface use filler.

Other option is cast steel as used in the rear drum/sprocket.

identification

How to Identify Metals in Engine Room? – Observation and Spark Test

Marine Insight - The maritime industry guide.

www.marineinsight.com

fiatfan · Dec 4, 2020

kommando said:
Malleable cast iron would be a possibility, used on footrests, centre stands, frame lugs etc. The item is cast iron but then heated for hours to drive out the carbon until the carbon level is the same as steel. The cast iron then takes the physical properties of steel so will bend instead of cracking. It will take a weld but risks creating a weak area, I would tap the holes for grub screws and then if you want a smooth surface use filler.

Other option is cast steel as used in the rear drum/sprocket.

identification

How to Identify Metals in Engine Room? – Observation and Spark Test

Marine Insight - The maritime industry guide.

www.marineinsight.com

What I think is a bit strange is that the "banana" part where the holes are is hollow..... Then again the threaded tube (don´t know the right word for that) that connects the upper and lower yoke must be welded to the lower yoke, and then the underside has been machined.

kommando · Dec 4, 2020

Steering stem, on the Commando and on 60's BSA yokes its a thick walled steel tube with a strong press fit into the yoke. Never had a Featherbed yoke in my hand but it looks very like the BSA B series heavyweight yoke set in construction.

Bernhard · Dec 4, 2020

fiatfan said:
So I have this lower yoke from an Atlas or early Commando, and some PO have drilled holes in it. I was going to weld them but wonder if they are made of some cast iron and it would require some special welding equipment, or is it steel? I have a standard MIG machine.
View attachment 20203

As a mere amateur, i strongly suggest you take it along to an experienced tig welder , there are so many different metals out there that your one size fits all mig is going to run you into trouble. And I'm speaking as an owner of a mig, who has welded steel, alloy and others, I just know when I'm getting out of my depth.

Hardwired · Dec 6, 2020

I consider brazing it. Much lower temperature, and since it is non structural, the strength isn't an issue.

Stephen Hill · Dec 6, 2020

I have oxyacetylene and tig and still wouldn't bother filling it with metal.
Fill it with bondo. Or epoxy thickened with fillers. The West system website has tons of info on filling holes.

Fast Eddie · Dec 6, 2020

Lazer welding. No heat issues AT ALL.

Or buy another. I confess, I’d be wondering if those holes have weakened it...

cliffa · Dec 7, 2020

Fast Eddie said:
Lazer welding. No heat issues AT ALL.

Or buy another. I confess, I’d be wondering if those holes have weakened it...

My thoughts exactly.

fiatfan · Dec 8, 2020

Hardwired said:
I consider brazing it. Much lower temperature, and since it is non structural, the strength isn't an issue.

I like that.

fiatfan · Dec 8, 2020

Fast Eddie said:
Lazer welding. No heat issues AT ALL.

Or buy another. I confess, I’d be wondering if those holes have weakened it...

I don´t believe the holes have weakened it, it just seems "better" to weld it.

concours · Dec 9, 2020

GMAW
GTAW
SMAW

it matters not.

jbruney · Dec 9, 2020

I like the laser weld idea myself.... Nothing the application of magic can't fix I say.

baz · Dec 10, 2020

I must admit I would have just welded those holes up and not given it a second thought

jbruney · Dec 10, 2020

So would I.... but there's nothing like magic.

maylar · Dec 10, 2020

How about tapping the holes for Loctited grub screws and filling the ends with epoxy or even Bondo?

edit: I see that kommando already suggested this. In lieu of epoxy, I thing brazing with brass would be better than trying to weld cast iron.

baz · Dec 10, 2020

maylar said:
How about tapping the holes for Loctited grub screws and filling the ends with epoxy or even Bondo?

edit: I see that kommando already suggested this. In lieu of epoxy, I thing brazing with brass would be better than trying to weld cast iron.

It's a maleable casting ,not cast iron

maylar · Dec 10, 2020

baz said:
It's a maleable casting ,not cast iron

What filler would you use with a MIG welder?

baz · Dec 10, 2020

maylar said:
What filler would you use with a MIG welder?

I would tig it up with a mild steel Tig rod
If I mig welded it I'd use 0.8 mild steel mig wire

kommando · Dec 10, 2020

Being Cast Malleable iron means is close to steel but not close enough to use exactly the same welding rods etc as steel. So take it to a welder with experience of welding Cast Malleable iron and get them to weld it, it will be easy for them and they will have the right filler rods in stock.

Early yoke welding

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