Can I Zinc INSIDE the hull?

[Cadence]

Originally Posted by Bleemus

Sorry for the mispelling. We had one on the Baltic 76 I worked on. Hooked up to an 8cyl Mercedes you could dial the grunt into it and power the boat around 10 knots at 1300 rpm if I remember correctly. Brilliant piece of gear.

[Wotname]

Originally Posted by noelex 77

This is no problem providing the thru hulls are not in electrical contact with the keel. Galvanic corrosion needs both metals immersed in an electrolite (seawater) AND electrical contact.

This is true and a very good starting point in understanding the problems but unfortunately the devil is in the detail.

While it usual to consider that the metals are separate entities, there is enough "galvanic" variation within one lump of metal (bronze, SS, iron etc) for it to corrode just by surrounding it with an electrolyte (i.e. seawater). In this case, the electrical contact is provided by the metal itself. So one bronze through hull sitting all by itself will corrode over time. Connect it electrically to a zinc (also sitting in the same electrolyte) and the zinc will now be the metal that is corroding.

As for the electrical connection, in a conventional wooden hull, the damp timber itself is a conductor and the resultant current flow though the timbers destroyed the cellular structure of the wood thus the practice was to bond all the through hulls together so there was a much lower resistance parallel path for the current flow i.e. the bonding wire rather than the wood.

Plastic hulls do not provide such an electrical connection and bonding through hulls is not good practice for a variety of reasons, not the least being the addition of a new set of dissimilar metals in the electrical path and the resultant maintenance requirements.

All of the above is enough reason to have breakfast with the bimbo...

[Bleemus]

Originally Posted by Cadence

I was referring to the Hundested. Just to complete thread drift.

[TrentePieds]

And here is the clip. Took a while to find it again.

This is a luvverly piece of boat handling - absolutely textbook! Note the change in revs as the pitch is varied. Note the "prop walk" at maximum pitch and how the skipper works the power against the inertia of the boat to spin her on her pivot point, and note the alacrity and confidence with which he ducks under the sprit of the coaster as he complete4s he 180º turn to leave harbour.

Note also that every so often it is necessary to reset the throttle to prevent a stall as the pitch is taken to maximum and to prevent "revving" when the pitch has to be left in "neutral" for any length of time.

Those were the days :-)!

[pdenton]

To be even more precise semantics refers not to the meaning of words but to the connotations of words. that is to say the way an assemblage of words modifies the meanings of the words in a phrase. Semantics is a very difficult branch of linguistics but I guess that's just semantics.
pdenton

[Sailmonkey]

Originally Posted by MarkJ

See the pink on the valve. It's not disco pink...

The buffed area on the valve outer wall had water leaking through it by some imperfection.

On the top surface there's pink but where it's been wire brushed away shows the metal inside is fine.

It's been installed for 2 years.

Are those the crappy valves that you purchased from Beneteau a few years ago? The ones that were never a great quality to begin with? The same ones that several people mentioned were not the best material?

[MarkJ]

Originally Posted by Sailmonkey

Are those the crappy valves that you purchased from Beneteau a few years ago? The ones that were never a great quality to begin with? The same ones that several people mentioned were not the best material?

Nothing else would fit.

Space is restricted so unless the boat is going at the speed of light nothing else fits.

Yes I want an Oyster. Please PayPal me $1.75 million.

Thank you.


☺

[Sailmonkey]

Originally Posted by MarkJ

Nothing else would fit.



Space is restricted so unless the boat is going at the speed of light nothing else fits.



Yes I want an Oyster. Please PayPal me $1.75 million.



Thank you.





☺

Ha, the light speed valve bend. I'm only mildly acquainted with that maneuver.

[MarkJ]

Originally Posted by Sailmonkey

Ha, the light speed valve bend. I'm only mildly acquainted with that maneuver.

Everyone thought the Theory of Relativity was something to do with making an Atomic Bomb. But Einstein was just trying to keep his boat afloat!

[Lawrence]

If you want a zinc attached to your bronze through hull then attach a bronze pipe tee to the fitting and thread a pencil zinc in to the tee.

[Paul L]

Originally Posted by Lawrence

If you want a zinc attached to your bronze through hull then attach a bronze pipe tee to the fitting and thread a pencil zinc in to the tee.

I like that solution, creative.