Brazing together bronze nuts

Well I make boat shafts. The full nut goes to the prop. As it is the one with all the force. The half nut is a lock nut. On a 1" shaft there is 3 choices Double nut, castle nut. Or nylock nut. All bronze of cores. I am not sure what You are trying to do.
 
yes galling can be a problem, if the shafts are put together with a good thread lube, ( the one we used is called n-5000 , it was a colodial nickle and I used it on stainless steel pump shaft couplings that ran in the pacific ocean for years driven by a 500 hp motor they came apart years later with no galling) you do what you want but I have some bronze , brass or stainless you can have if you send me your address bill
 
Thanks all and especially @spike7638 for asking for this very interesting conversation.
Never too old to learn!

-brino
 
I am a machinist in a prop shop. Best thing the op can do is paint his prop with zinc chromate primer. I see rudders all the time eaten up with electrolysis every where except under the zinc anode. Putting a large enough zinc anode on the prop nut would interfere with the flow.
 
Hi Spike,
i'm a landlubber, and i don't know squat about maritime engineering.

i can offer a trick to weld nuts together and still have them useful as a nut
blacken a mild steel threaded shaft with carbon soot from an acetylene flame and thread the nuts on in the orientation desired
put the assembly in a vise for stability and check to see that the threaded rod still turns in the captive nuts
tack the nuts on the corners and tig the nuts together with silicon bronze
remove the threaded rod and finish as desired
if the threaded bore is tight, run a standard tap through the bore.
i wish you the very best of luck
 
Mitch Alsup said:
And if you must guarantee electrical conductivity, any kind of soldering at the joint will do that.
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True...but once again, more metals leads to more potential for electrolysis, so brazing (with silicon bronze) has its appeal.
 
kd4gij said:
Well I make boat shafts. The full nut goes to the prop. As it is the one with all the force. The half nut is a lock nut. On a 1" shaft there is 3 choices Double nut, castle nut. Or nylock nut. All bronze of cores. I am not sure what You are trying to do.
Click to expand...
You might want to take a look at the article that someone else referenced, which shows that the ABYC and other engineering groups say the opposite about the order of the jam nut and the bit nut (https://www.passagemaker.com/channels/propeller-nut-myth-busting). Then again, with your experience, you may say "Forget the engineers -- I know what I'm doing!", and I'm sure it's worked out fine for you over the years.

Personally, I suspect that in almost all applications of the sort that matter to me, it's completely irrelevant: I've got a 1" shaft, a 15 x 15 prop, and it turns at about 1200 RPM, tops, driven by a westerbeke 40, which puts out (depending on which literature you read) 40 HP, 37 HP, or 28 HP. :) Regardless of which it is, it's too little to matter a whole lot, esp. because it's on a sailboat where I seldom use the engine to push us along.
 
kd4gij said:
I am a machinist in a prop shop. Best thing the op can do is paint his prop with zinc chromate primer. I see rudders all the time eaten up with electrolysis every where except under the zinc anode. Putting a large enough zinc anode on the prop nut would interfere with the flow.
Click to expand...

The chance of my rudder being eaten up with electrolysis is very slim: it's made of fiberglass. :)

My prop is bronze, and the donut-zinc has been working on it pretty well for the last 30 years. I just want to be able to move up one size, so that I replace it once a summer rather than twice.

The prop is in an old CCA-rule cruising boat, with the prop in a too-small aperture, sitting about 2 inches behind a 3-inch-wide deadwood. The donut near the center of rotation isn't the thing screwing up the flow ... or if it is, it's only providing about .01% of the screwup.
 
bfd said:
yes galling can be a problem, if the shafts are put together with a good thread lube, ( the one we used is called n-5000 , it was a colodial nickle and I used it on stainless steel pump shaft couplings that ran in the pacific ocean for years driven by a 500 hp motor they came apart years later with no galling) you do what you want but I have some bronze , brass or stainless you can have if you send me your address bill
Click to expand...

Wow...that's very generous. Let me get back to you if I can't figure out some other way to get the job done.

That n-5000 looks like amazing stuff. It should be for $75 a tin. :)
 
Which way to install the nuts wouldn't be an issue if you used two nuts of the same thickness. :idea:
 
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