welding/fixing broken cooling fin

[greg78gs750]

Hi all,

I have a broken cooling fin on my 1100, what is the forum consensus on fixing this? Anyone have any luck with a tig? Brazing? Thanks for any advice!

Greg

[Steve]

Probably not worth the trouble to fix it. That one fin isn't going to hurt much.

.

[Nessism]

TIG might work. Brazing won't (I tried and failed) since it's impossible to get it hot enough.

[greg78gs750]

I'm worried more about aesthetics than cooling. Long term I plan on sourcing a new cylinder block for a big bore. Maybe i will just live with it.....ech.

[tkent02]

I built part of a cooling fin out of JB Weld, you couldn't tell once it was painted.

[BigD_83]

I built part of a cooling fin out of JB Weld, you couldn't tell once it was painted.

Do you have pictures of that job at various stages? How'd the JB Weld hold up to the heat over time?

[tkent02]

Not sure, no pics it was a long time ago. I think the JB would hold up, it stays put just fine inside intake and exhaust ports. Probably not real strong if you knock it with a wrench or something but heat alone won't hurt it. Have used it on engine blocks, radiators, motorcycle cases, other things that get hot and it stays for years.

[BigD_83]

Not sure, no pics it was a long time ago. I think the JB would hold up, it stays put just fine inside intake and exhaust ports. Probably not real strong if you knock it with a wrench or something but heat alone won't hurt it. Have used it on engine blocks, radiators, motorcycle cases, other things that get hot and it stays for years.

Good tip. Beats the heck out of pulling an engine apart for a small cosmetic adjustment.

[greg78gs750]

if the engine wasn't already apart, I would for sure be turning to the jb. I have a buddy who is a welding instructor, pretty good with tig, I think i will have him assess it and maybe give it a go. Thanks for the ideas!

[GregT]

TIG welding alloy fins is easy enough. I've had several heads repaired this way during restorations. Worst was a Z1 with most of 3 fins on one end missing.
Good welder locally built them up and reshaped them, you'd never know.

Cast iron is actually easier - bronze weld with the right flux.

[greg78gs750]

good info gregt! i have the broken off piece, hopefully he can just tack it on without causing too much mayhem. I got a degree in "welding technology" from these guys, they are pretty good. My skills are too rusty to attempt it myself.