Welding up a fin

I disappointed myself by dropping this jug on the floor. Now I know how at least some of these things happen.

Here is how it turned out.

Good job.

motorson said:

I disappointed myself by dropping this jug on the floor. Now I know how at least some of these things happen. View attachment 98862

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Wish you were near me - got a Dommie 99 that needs this ..

Good job. Did you have to preheat the head? What kind of rod?
Jaydee

Looks like a hi nickle cast iron rod , nice tidy peening .

motorson said:

View attachment 98864View attachment 98863Here is how it turned out.

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Very nice job
I hope you didn't get any arcing from that earth clamp in the bore

The rod is pure nickel. The method is to weld very short tacks mostly one at a time and then peen them real good as they cool. Never put down a new tack until you can lay your hand on the job without pulling away. I used little wooden wedges to hold up the fin as I got going then pounded them in tighter when I thought it wouldn't break the fin off.

The theory is that the peening expands the nickel as the cast iron is cooling so the nickel does not pull away from the cast. No preheat at all. It does make a very strong bond which I have seen used in some very harsh and surprising applications. I learned the method from an old farmer when I was a 14 year old kid. I had cut apart a cast iron kick starter on an old Cushman to get it to miss the frame on a mini bike. My dad could weld most things but not that so he got the farmer to come over. The guy spent half a day welding my kick starter, It never broke and I never forgot how to do that kind of weld.

No worries about potential arcing on this job since I plan to sleeve it down to 500cc.
Dan.

I have always peened my welds on cast iron but I've never known why