Pink metal on stuffing box

[L124C]

I know that generally pink is not good when it comes to metal. Is the pink on this stuffing box (forward edge) something to worry about?

[MSter]

yikes!!! I hate that color...Just experienced a pink strut and it was not cheap. Get it under control while you can. Have you been going through shaft zincs?

I no longer plug my boat in to shore power unless absolutely necessary. I am not sure if this is going to help but figure the less paths the boat offers to ground, the better off I will be.

[captflood]

GREETINGS EARTHLINGS; A good rub with a stainless steel wire brush (so you dont' leave any nasty rusting hairs behinde) and a good dollop of kalsite under-water grease should keep you going for a few more years, keep it clean and keep it well greased GO SAFE

[RichH]

Sure is a problem. Bronze is a mixture of copper and tin ... and with a wee bit of zinc added to aid 'machinability'. When electrolysis begins, and there isnt a proper 'anode' connected the electrical potential will use the zinc in the bronze casting as its anode ... the result is the metal alloy turns 'pink' as the zinc is consumed .. and then the metal becomes 'spongy'.

This is also a warning that possibly that the metal wasnt really a 'true' bronze but rather a 'red brass' with lots of cheap zinc added and the tin content 'reduced'. Lots of asian 'bronze' is actually 'red brass' (zinc loaded 'bronze').

[sea_hunter]

Yikes, I agree with MSter. Tap it with a bronze drift, if it sounds punky, time to replace.

[L124C]

Originally Posted by MSter

yikes!!! I hate that color...Just experienced a pink strut and it was not cheap. Get it under control while you can. Have you been going through shaft zincs?

I no longer plug my boat in to shore power unless absolutely necessary. I am not sure if this is going to help but figure the less paths the boat offers to ground, the better off I will be.

Going through a prop zinc about every 1.5 years. I've tested the water for current and don't find any.

[Tim R.]

Originally Posted by sea_hunter

Yikes, I agree with MSter. Tap it with a bronze drift, if it sounds punky, time to replace.

Please haul the boat before you do any tapping.

[L124C]

Originally Posted by captflood

GREETINGS EARTHLINGS; A good rub with a stainless steel wire brush (so you dont' leave any nasty rusting hairs behinde) and a good dollop of kalsite under-water grease should keep you going for a few more years, keep it clean and keep it well greased GO SAFE

Are you saying to grease the exterior surface? If so, what does that do?

[L124C]

Originally Posted by RichH

Sure is a problem. Bronze is a mixture of copper and tin ... and with a wee bit of zinc added to aid 'machinability'. When electrolysis begins, and there isn't a proper 'anode' connected the electrical potential will use the zinc in the bronze casting as its anode ... the result is the metal alloy turns 'pink' as the zinc is consumed .. and then the metal becomes 'spongy'.
This is also a warning that possibly that the metal wasnt really a 'true' bronze but rather a 'red brass' with lots of cheap zinc added and the tin content 'reduced'. Lots of asian 'bronze' is actually 'red brass' (zinc loaded 'bronze').

So, the zink on the prop shaft isn't a proper anode?
By "spongy", I assume the consumed Zinc creates voids, and therefore makes the fitting weak?
Other than price (no longer a sure fired indication of quality, now that China has cornered many markets), how can I tell if the replacement is true Bronze?

[L124C]

Originally Posted by treilley

Please haul the boat before you do any tapping.

Wow!!! It could be THAT brittle?
I assume "punky" is a dull, (not sharp metalic) report? (PUNK vs. PINK)
If so...it might sound like PUNK, PUNK, SPLASH!