Bronze rudder shoe - Taiwanese boats

[Cadence]

Originally Posted by rbk

Machining bronze that is suitable in this application is difficult at best. Other alloys are easier to machine (higher zinc content) as you move more into brass alloys which would be very unsuitable in this application. This is why most quality bronze alloy marine parts are cast. Brazing a broken/cracked part can be accomplished but wont be as strong as the original casting, not something you want holding your rudder in place.

I had a good welder weld white metal which I was told wasn't weldable. The guy had a refrigerator full of different rods and a welder as a big as the reefer.
He was retired from the Navy Yard.
Brazing no, ask a real welder if you can find one.

[rbk]

Originally Posted by Cadence

I had a good welder weld white metal which I was told wasn't weldable. The guy had a refrigerator full of different rods and a welder as a big as the reefer.
He was retired from the Navy Yard.
Brazing no, ask a real welder if you can find one.

White or pot metal has no specific alloy, so yes its possible that it could be high in aluminum (or simply cast aluminum) for instance and be weldable but really depends on the alloy.

[Jim Cate]

Originally Posted by Cadence

Maybe I missed it? What is wrong with the part?

bump!

Yes, please tell us why it needs replacement. Perhaps we can suggest way to avoid replacement... ya never know!

Jim

[badadim]

Thank you all for the information and help. A very talented engineer designed a replacement and changed the design so it will be easier to CNC. Presenting the outcome.

[badadim]

Originally Posted by Jim Cate

bump!

Yes, please tell us why it needs replacement. Perhaps we can suggest way to avoid replacement... ya never know!

Jim

Hi Jim,

Galvanic corrosion damage to the boot, bolts, pins. It was possible to repair, however the legacy design made rudder drop process a bit more complected - everything should come down and up at same time: the boot and the rudder synchronously.

Not able to get a balanced solution between quality and cost could have resulted in a repair for sure. However, I was lucky to meet a guy who helped with re-design and from there the task became very much finding a good CNC shop. It was not easy, and some of the quotes I got were very high. Casting was the most expensive plus the shrinking issue. At the end, I found a reputable CNC local shop who made the new boot in 316 for a very reasonable price.

It ended to be an interesting project, with getting new friends, 3D printing the prototype and a lot of lessons learned. Fun never stops!

The new boot is isolated from the boat bonding system entirely with own anodes. And.. rudder drops in just 20 minutes.

Glad to share the details with those who run into a similar situation.

[Searles]

Depending on size ,bigger is easier we would fabricate one ,local machine shop,or using the old one as a pattern cast in G1 bronze also local ,depending on cost .⛵️⚓️

[badadim]

Need help from the community with the next step around the new boot project: epoxy + antifoul vs antifoul on steel vs exposed? What is best for 316L below waterline in salt water?


Thank you all in advance.

[Spot]

The part looks nice Badabim.
You may want to start a new thread specific to the painting question(s) to get more visibility.