Transom zincs

[Parrot Adventure]

I received a message from a fellow Albin 36 DC owner regarding what the role of transom zincs is and what they are connected to, so I thought a new subject regarding them should be helpful to him and all others in this subset of 36/37/40/43 Albin owners. It is my understanding the transom zincs should be connected to the boat's original copper bonding strip which is located in the lazarette near the rudder quadrant and assembly. That copper strip should run throughout the entire length of the boat, and is used to "galvanically" connect all the bronze thru-hull fittings and seacocks back to the two transom zincs as well as the negative side of your 12 volt power strip. On our boat, the factory installed copper strip was intact, but I needed to run copper wires from the transom zincs to the copper strip using #8 copper wire. I have attached a photo of the wires I ran from the zinc's bolts to the copper strip below as an FYI. I believe I also had to run individual bonding wires from each of the swim platform's mounting bracket bolts to the bonding system as well. Does this seem reasonable? Anyone else have further suggestion for our new Albin 36 owner? Thanks, Mark

[kjg1951]

thank you ... I bet the wires are not connected to the copper strip ....I will check this weekend I will try to get a pic of the swim platform mounts ... great pic..
Kevin

[Parrot Adventure]

Also, I used readily available bronze mounting clamps to connect the new grounding wires to the zinc's bolts. Just be sure to replace the factory provided steel bolts in those clamps with stainless steel or bronze bolts to avoid corrosion! Here are what I purchased to make the connection, and which come in a variety of sizes: http://www.homedepot.com/p/Blackburn-1- ... /202907610

[crowra]

Thanks for starting this forum! The nuts that hold my transom zincs need to be replaced but they aren't standard or metric. Since the boat was built in Taiwan, I'm wondering if they are British as in BSW (British Standard Whitworth)? Also, I understand it's possible to connect your shaft (by some kind of 'wire brush' that rests on the shaft) to the transom-zinc bonding system so you don't need zincs on the shaft. Has anyone done that?

[kjg1951]

Here is a pic of the problem any thoughts ?

[kjg1951]

Swim platform support

[Parrot Adventure]

Hi Crowra, thanks for your reply and questions. I recently replaced my boat's cutless bearing during haulout (see separate "Cutless Bearing Replacement" topic and photos in this 36/37/40/43 subforum). It was a big job but glad I did it myself and with input from other experienced AOG members. With regard to your question on the thread pitch on those transom zinc mounting bolts, YES, they are 1/2" X 12 thread per inch (TPI) BSW bolts. American standard 1/2" 13 TPI nuts will not work, so your options are either to replace the BSW bolts entirely with 1/2" X 13 TPI or purchase BSW 1/2" X 12 TPI. I found a vendor in upstate New York who specializes in BSW hardware: http://britishfasteners.com/threaded-ro ... 9003a.html With regard to your question re: connecting a bonding wire/brush to the shaft, I have a 1-1/2" collar zinc mounted underwater on our shaft between the cutless bearing housing and the prop. In our bonding system, I also used 8-gauge wire to connect the shaft stuffing box to the boat's copper strip bonding system as "double protection," although I do see quite a bit of green oxidation on that stuffing box likely because of the drip drip drip drip seal I have. I personally like to provide as much galvanic protection as I can, using the philosophy that zincs are more inexpensive and easier to replace than the items they're protecting. Also please see the general zinc discussion and transom/shaft collar zinc photos I provided at: viewtopic.php?f=7&t=8942 I hope this helps. Thanks, Mark

[catalina_mike]

The bonding system on my 28 TE was a mess and I redid most of it and added a transom zinc before my first launch after purchase. The vessel did not have one.. I also redid all the connections at the thru hulls and bonded the swim step supports after the fact. I think I'm doing pretty good as the only thing the bottom cleaner said was about the swim step supports initially. They were painted and when I was on the hard I never thought they would need bonding.

[Parrot Adventure]

Hi kjg1951, please see a similar discussion at: viewtopic.php?f=7&t=8942 and photos of our transom in that discussion. In my opinion in looking at your photos, it appears there's some galvanic reaction occurring at and around the swim platform brackets, so if you're able to bond these to the zincs in the lazarette, you should be good to go. Another option which is more costly but likely effective is to possibly install the appropriate-sized (1" diameter?) collar zincs directly to the swim platform tubing, but I think you should be fine connecting (or cleaning up the connections if corroded) to the transom zincs in the lazarette. Keep us posted. Thanks, Mark

[kjg1951]

I am going to put zincs on each swim platform tubing until I can find out what is going on with the connections in the lazarette...

[mike66]

All my metal fitting corrosion stopped when I switched to copper free bottom paint. I think the copper aids electrolysis around the fittings. I used Petit water- based with econea ($$$$) but one coat easily lasts 2 seasons here in RI. I paint one half of the boat per year over metal, transducers, etc. Even stays on the prop for our 200+ hours of cruising.