[Vectric]

Hey All, New to this Forum but I've been extremely thankful for all of the videos provided by Jody.
Did a preliminary search and found a video posted about Tig brazing with silicone bronze I'd love some input as to whether this is the best option for my project.

I just pulled a 3 blade brass prop (12" diameter) off of a sailboat, and it has been eaten away badly by electrolysis. I've sanded the whole thing down as much as I feel comfortable and had planned to build it up with silicone bronze filler rod using the Tig torch. Alternatively I was thinking of using some brass or bronze stock to braze and shape.

I will most likely be purchasing a new prop given the current condition, but I want to try the repair regardless

My question is this: Can porous corroded metal be repaired with this method?

would it be better to try brazing with oxy/fuel?

Any advice is appreciated

Cheers, Jay

[Sandow]

You are going to find that welding brass sucks as soon as you try it. Brass is copper/zinc so it will blow off zinc fumes when it gets hot so wear as respirator and don't melt the base metal. It will never be pretty but if you are just filling pits, you should be fine.

https://www.youtube.com/watch?v=7udYchu6Csc

-Sandow

[Cbking]

I work at a prop repair company and I would highly recommend send it some where to be professional rebuilt. When we do brass props they are both statically balanced a dynamically balanced. We can also do mri scans of props to verify pitch to make sure that everything is right. We will also polish them through a wet and dry polisher.


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[weldin mike 27]

We do repairs to SHIP props at work. The Base metal looks like brass to the unenlightened, but is actually Nickel Aluminium Bronze. Im not sure how to test your prop to see whats what, but I know that Ampcotrode make a specific filler for the metal, that is actually welded. AC tig i beleive.

Mick

[xryan]

I highly doubt that your prop is brass. MOST likely it is bronze or what Mike said what is commonly referred to as "Nibral" (nickel/bronze/aluminum). It's not just used for big ship screws that he probably is referring to but small stuff as well (sail boats/ski boats/sport fishing, etc. Not to discourage learning buy any means but you'd be doing your prop a disservice by practicing with it if you're going to put it back on your vessel.

Unless the prop is really destroyed it's VERY economical have it reconditioned and your engine and shaft will be much happier and run better when it is static and dynamic balanced after refinishing any damaged spots. The MRI machine can easily do what no master tig welding superhero could dream of and show you where it needs fixin. Basically it's a coordinate measuring machine or CMM in any other industry. I don't know why they came up with new lingo to make people think your prop is getting sent to the hospital.

If you have "bad" pitting like you said, you've got other electrolysis issues going on and it's not just the prop tgst will get eaten. You should check your zincs and mooring area for stray current.

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[Cbking]

I highly doubt that your prop is brass. MOST likely it is bronze or what Mike said what is commonly referred to as "Nibral" (nickel/bronze/aluminum). It's not just used for big ship screws that he probably is referring to but small stuff as well (sail boats/ski boats/sport fishing, etc. Not to discourage learning buy any means but you'd be doing your prop a disservice by practicing with it if you're going to put it back on your vessel.

Unless the prop is really destroyed it's VERY economical have it reconditioned and your engine and shaft will be much happier and run better when it is static and dynamic balanced after refinishing any damaged spots. The MRI machine can easily do what no master tig welding superhero could dream of and show you where it needs fixin. Basically it's a coordinate measuring machine or CMM in any other industry. I don't know why they came up with new lingo to make people think your prop is getting sent to the hospital.

If you have "bad" pitting like you said, you've got other electrolysis issues going on and it's not just the prop tgst will get eaten. You should check your zincs and mooring area for stray current.

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Using both MRI and dynamic balancing is quite important to keeping the vibrations down. I agree with everything stated above.