Zinc on my pod?
- Thread starter DuroBoat
- Start date
Corey_lax
Crew Member
Is there an access hatch to get inside of the pod? You could drill a hole and put a bolt in from the inside-out. Tack weld it in place. Bolt a U shaped aluminum piece to that and mount a sacrificial anode to that. You’re basically just looking to ground it out sort of and provide a metal that will break down before the aluminum so they would all be connected at that point.
But also yeah, if your pod is powder coated nicely, it probably doesn’t matter anyways. Especially if it’s rarely left in the water
But also yeah, if your pod is powder coated nicely, it probably doesn’t matter anyways. Especially if it’s rarely left in the water
ship happens
Crew Member
I wouldnt drill a hole in that pod. The engine has a pretty good sized zinc on the bracket under the trim pump. One thing i always do is tap a 10/32 screw into the backing plate on the inside of the transom, then put that right into the ground disty. Then your pod is bonded to ground through your battery cables. Your engine has zincs
Gotta remember stainless into aluminum is not good under the water line.
Gotta remember stainless into aluminum is not good under the water line.
CIVANO
Well-Known Member
I am not being a smart butt but what word did you intend rather than disty?
ship happens
Crew Member
Haha was not a typo. It's short for distribution.
ship happens
Crew Member
Pods are grounded as soon as you bolt and outboard to it. " bonding " is..
In the US transport regulations is has been a requirement for a long time. Unless its all the same metal type. Like a thruhull fitting, however a lot of boat builders are now bonding all of those as well. Its why Groco and Buck Algonquin has tapped machine screws on their fittings. Its transport standard on this to use a 10ga green wire. Not transport canada, but most other places in the world
Bonding
- Once you have electricity on board, even if it’s just an engine, battery, cabin lights and VHF radio, the possibility exists of electrolytic corrosion to metal parts of the boat. The purpose of bonding, as described by ABYC, is to: (Upgrading the Cruising Sailboat, p. 273)
- provide a low-resistance electrical path inside the hull between otherwise isolated metallic objects, especially those in common contact with sea water
- prevent the possibility of electrical potential on exposed metallic enclosures of electrical equipment
- provide a low-resistance path for excessively high voltages, such as when the boat is struck by lightning
- to minimize radio interference. Boats without permanently installed electrical systems do not need bonding.
In the US transport regulations is has been a requirement for a long time. Unless its all the same metal type. Like a thruhull fitting, however a lot of boat builders are now bonding all of those as well. Its why Groco and Buck Algonquin has tapped machine screws on their fittings. Its transport standard on this to use a 10ga green wire. Not transport canada, but most other places in the world
ship happens
Crew Member
Its called Bonding. Aluminum boats are ground as soon as you bolt and engine to it, or any type of running gear. What bonding does in a shorter sense is gets rid of high impedance paths, and provides a more nominal resistance to ground throughout the different parts and pieces of a boat, while offering the same path to isolated parts such as thruhull fittings. In fibreglass boats since the thruhull fittings are all made from the same type of bronze, its not a requirement, however like I said most boat builders now are bonding those as well.
dance a jig
Active Member
Option A is 1) drilling how in pod, 2) grinding away powdercoat on inside of pod if any, 3) mount a 316 SS stud with big washer making contact with fresh aluminum on inside of pod, 4) apply some 5200 where stud exits pod then slip nylon washer, then SS washer, then nut on outside of pod to secure stud tight, 5) apply 5200 around big washer on inside of pod. With these steps, the power coating should be protected, and the pod aluminum is now in contact with the stud.
Option B is 1) big butt zincs mounted on both trim tabs, 2) grounding wire (copper?) linking trim tabs to mounting bolts of pod. The sacrificial zinks on the tabs should them protect the pod.
Proximity is important as many yachts with inboards which spend year around in an electrolyte where the dissimilar metals set up a galvanic action,, where the typical practice is to have a big hull zinc which connects via bonding wire to all the bronze through hulls that are underwater, and other underwater hardware including shaft brushes, but there are still separate shaft zincs located to safeguard the props and shafts. My take is "you cant have enough zinc protection", hence pod has own zinc, outboards have own zincs, trim tabs have own zinc, and if through hulls, they should be connected to something (tabs zinc?) to protect them. Because of this, I favor Option A because with Option B, some stray electrolytic corrosion may cause your pod powercoating to bubble if not protected as an independent component.
Lots of other opinions about this on website https://www.thehulltruth.com/
good luck. DAJ
Option B is 1) big butt zincs mounted on both trim tabs, 2) grounding wire (copper?) linking trim tabs to mounting bolts of pod. The sacrificial zinks on the tabs should them protect the pod.
Proximity is important as many yachts with inboards which spend year around in an electrolyte where the dissimilar metals set up a galvanic action,, where the typical practice is to have a big hull zinc which connects via bonding wire to all the bronze through hulls that are underwater, and other underwater hardware including shaft brushes, but there are still separate shaft zincs located to safeguard the props and shafts. My take is "you cant have enough zinc protection", hence pod has own zinc, outboards have own zincs, trim tabs have own zinc, and if through hulls, they should be connected to something (tabs zinc?) to protect them. Because of this, I favor Option A because with Option B, some stray electrolytic corrosion may cause your pod powercoating to bubble if not protected as an independent component.
Lots of other opinions about this on website https://www.thehulltruth.com/
good luck. DAJ
Brando
Well-Known Member
I understand what bonding is and it’s purpose and importance. What I am saying is your added wire offering a second path to ground for a high amperage alternator and all of the electrical components associated with the outboard you have now effectively made the large aluminum structure underwater part of that circuit. That will cause electrolysis I’ve seen it happen. Better off not to and only utilize the ground on the engine effectively keeping stray current from traveling through the pod aluminum is a very good electrical conductor. Bonding other components like thru hulls is a good idea.
ship happens
Crew Member
It's already part of that circuit. It's a bond for galvanic corrosion. I can show you pictures of boats that have been build by myself and other people that have been in the water for years. With no issues of galvanic corrosion. Is the bond nessesary? Nope. Does it help with some instances of galvanic corrosion? Yep. It's why the US transport regulations require it.
It's not really a second path. It's more like nominating the impedance throughput the entire circuit. The engine charging circuit will go through the least resistant path which is the 4 gauge or 2 guage battery cable. Which is why we move to 2 gauge after the 10 foot rule
It's not really a second path. It's more like nominating the impedance throughput the entire circuit. The engine charging circuit will go through the least resistant path which is the 4 gauge or 2 guage battery cable. Which is why we move to 2 gauge after the 10 foot rule
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Aquaholic
Crew Member
Do you need a transducer bracket too? Brando did my boat, not a pod, but both brackets were exactly as we discussed and perfect. Super happy with how it turned out.Great info here, my pod is just getting sent off for powder coat and I woulda forgot about the anode bracket but my pod builder remembered
A-a-Ron
Well-Known Member
I was gonna go with a thru-hull transducer
SpringVelocity
Crew Member
Great info here, my pod is just getting sent off for powder coat and I woulda forgot about the anode bracket but my pod builder remembered
Just advise before it goes in....Make sure you insist that whoever gets your pod powdercoating put an extra layer of primer (pre-treatment) under it, and it is properly done. Pay extra for the primer it's worth it. 4 step process if done right: sandblast, etch, primer, and then the powder.
A lot of the peeling is from shops just doing the acid etching and going straight to powdercoating which is not wise. Anything goes outside needs an under layer of primer before final powder is baked on.
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SpringVelocity
Crew Member
Do it. Its a pain and butt to put it on pod.
ship happens
Crew Member
Is there an emoji for this? Do you guys not understand how powder coat is a total nightmare and how you cannot have stainless fasteners below the waterline? You cannot have a weld on bracket and end the powder at the bracket. You also cannot disturb that powder on that bracket. You will induce galvanic corrosion and that powder will not last. Once you get that powder bubbling, it keeps going and you can't do anything about it. It will go eventually, especially when you Moore it. Put one stainless bolt through there under the line and I give it 6 months max moored.
Ps, to @DuroBoat
See those little what looks like number 8 tapping screws, or maybe machine screw holding that little buttplug in place? Yup that's not accepted in the boat world. Transport canada not accepted as new buildings procedures. Not even in Canada. That will induce galvanic corrosion so baldy those will snap off and the aluminum will be fully dicked. The only way on a powder coated pod to get as much out of that precious powder as possible is a welded bung FIP before the powder and use a merelon M-NPT plug.
Ps, to @DuroBoat
See those little what looks like number 8 tapping screws, or maybe machine screw holding that little buttplug in place? Yup that's not accepted in the boat world. Transport canada not accepted as new buildings procedures. Not even in Canada. That will induce galvanic corrosion so baldy those will snap off and the aluminum will be fully dicked. The only way on a powder coated pod to get as much out of that precious powder as possible is a welded bung FIP before the powder and use a merelon M-NPT plug.
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