? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damage

[191Seanymphstriper]

My younger brother has a 18 starcraft CC that I had never had a chance to see before yesterday. He lives in N.J. He is not like me as far as rebuilding and restoring aluminum boats. But he does love the aluminum boats.

He is the type to just do things quick and just go fishing etc. Well he has had some motor trouble and he brought the boat over to pops house yesterday and when we got home from fishing on my boat we took a look at her.

Well first off his zinc was eatin to the core. half hanging on. Almost totally gone. I crabed the zinc and it fell off the bolt into my hand. So he ran and got new zincs as I changed his plugs and coils and cleaned the carbs and she fired right up. So that parts fixed.

My brother then got back with the zincs and We were installing them and I got a close view under the hull etc... I fount that on the outer side spray chimes and the under hull keel chims there where lots of pitting, Along the stained water line especially in the outer transom there was alot of pitting as well where the water sits when the boat is docked.


He had painted the bottom of the boat with trilux 33 but he diddnt come up high enough with his water line with the bottom paint. He also just sanded it and applied the trilux 33...


Now when i paint the bottom they sell a primer that you use to apply before you add the trilux 33 and I do things a bit diff so I dont have this issue.

Also I have a dual battery charger by guess that after reaches full charge becomes a maintance trickle charger and shuts on and off to maintain full voltage of the battery. I also have a switch to turn off the dual batterys when im charging and not using the boat. I also keep my boat in salt water and charge it etc

Now my brother has a single battery and a single guess battery charger as I do but with no switch.

But he my brother just does things kinda half A%% .... So my question is this.

1. What are your thoughts as to what caused the electrolysis to start eating at his boat?

2.Is it the fact that he never pulled his boat out every month and checked his zinc and the boat started to get attacted by electrolysis?


3.Or is it the fact that he did not apply bottom paint to where the water line was supposed to be?


4.Or is it the fact that he did not prime before adding the trilux 33 and the bottom paint is causing the electrolsis to eat away?



5.Or is it the fact that his charger is charging a battery that is directly connected to the boat with no switch to cut direct current to the boat while charging?


What can he do to further prevent this from happening again?

I told him that Over the winter I will aluminum soder weld these little spots and sand them down to a like new finish for him but he dosent want me to
"Go all out he said" My brother is hard headed and I think he likes to do things himself! Like I said hes not as anal as I am about theses boats either.


6. So also what is a easy quick fix that he can do to fill in these little craters himself where the electrolysis ate the aluminum? G.B Weld? Is there a aluminum type bondo?


He brought the boat home last night and wants to put it back in the water asap But im trying to get him to do some type of a repiar before he puts her back in...........

Any input, advise, thoughts, etc would be greatly appreciated! So thanks in advance for any input.

 

[Silvertip]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

Since the ground side (negative cable) on the battery or batteries remains connected to the engine the hull is also at ground potential so disconnecting the positive side with a switch has no real advantage. Outboards become bonded to the hull with the bolts used to secure the engine to the transom. Perhaps everything you mention can have a bearing on corrosion. Perhaps the power wiring at the slip is also at fault.

 

[rwidman]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

If he's going to charge the battery with a charger while the boat is in the water, he should disconnect both battery leads before charging the battery. I suppose he could install two battery switches to make it easier. Or install a galvanic isolator. I've never heard of anyone installing one of these on an 18' boat.

 

[191Seanymphstriper]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

A gal isolater is great but would be to much for a small boat like his with a 6 amp battery charger on it. He keeps it charged for his auto bilge pump that goes off every 10 min.....


But the battery charger is supp to turn on when batt are low and trickle when full. So is there even that much current coming off the ac line connected to the charger? And keep in mind he is using a adapter with a regular extension cord that you would buy from home depot that is pluging directly into a guess battery charger that is hooked to 1 battery. ???????



On my boats I put a 2 circut breakers in the transome one on the positive coming off the motor and one on the negative coming off the motor. And I also have a daul battery switch. With daul batterys.

But when Im at the dock I disactivate the positive breaker and the negative breaker which basically is interupting a complete circut. It disconnects the motors positive and negative completly from the batterys. I then plug in the charger that is hooked up to both batterys.


Now The only thing hooked to those batt is the bilge pump and the acc control panel switch which is always turned off so thers no complete circut there as well... Also the battery switch is turned off so the acc panel dosent even have power to it. So the only complete circut on the boat is the bulge pump and the battery charger charging the batterys ......

Correct me if im wrong please, but Am I in the right for leaving the negative breaker disengaged as well as the positive while the boat is charging? Or should I leave the negative breaker on so the boat has direct ground to the engine block?


Because if this is the case i will tell my brother to buy a set of breakers and install them in his boat like I was doing. Or 1 breaker if what I am doing is wrong... ????? This is a subject that stumps me and confuses me everytime bc the boat is aluminum.....


All I know is after seeing his boat I do not want that to ever happen to my boat! Or any 1 elses.... it was upseting


Please help

 

[191Seanymphstriper]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

Since the ground side (negative cable) on the battery or batteries remains connected to the engine the hull is also at ground potential so disconnecting the positive side with a switch has no real advantage. Outboards become bonded to the hull with the bolts used to secure the engine to the transom. Perhaps everything you mention can have a bearing on corrosion. Perhaps the power wiring at the slip is also at fault.

So lets say I put 2 batterys connected to nothing in plastic battery boxes on the wooden floor in the middle of no where on my boat, and then I hook them up to a battery charger at the dock while the boats in the water.

Would this still cause The boats negative magnectic fields (because the motor is still a ground) to still hold the aluminum accountable as the weekest link?

Or is the motor not a ground because the batterys arent hooked up to it?


And after the zinks are done doing there job will the fact that the batterys are charging on the boat in the water, will it still cause electrolysis to deform and attack the aluminum boat just because the motor is a ground causing a negative field on the boat?


So any foreign charge (positive) power etc will still cause electrolysis? Lets say someone dumped a old engine block under where he is docked. Electroylosis would still attack a aluminum boat because of that. Correct?


Geese.... My heads spinning here..... This is the one thing I hate about aluminum on water.


Listen his zink deff did its job. Do you think that the fact that the zinc was basically that far gone that then the electroylosis started eating his boat? i would have thought it would have attact the prop or engine housing etc first???

Im thinking that if he did check his zinks and had a good zinc on there that this would have never happened.

The charger is so small as in amps 1amp trickle charge 6amps full charge and it says on it. Good for small aluminum boats!

What do you think?

Also he stated that the boat never looked like that 4 months ago. So Im gussing in 4 month that zinc was way over due. I change my zincs every month if it starts looking a little eatin up...


Im kinda pist off that this happened to him and that little boat is really nice. I told him to mount a 2 zincs on port and starb of the outboard on the transom below the water line. This is what I have been doing as a extra precaution.

My boat is always hooked up to the shore power. Even last year before I had the extra zinks. And When i pulled my boat last year 4 times I only changed my zinc one time. But it was never falling off like that...


He has all plastic fish holders etc. Nothing stainless or foreign material etc... I just dont get it....

Its a shame!

 

[rwidman]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

A gal isolater is great but would be to much for a small boat like his with a 6 amp battery charger on it. He keeps it charged for his auto bilge pump that goes off every 10 min.....


But the battery charger is supp to turn on when batt are low and trickle when full. So is there even that much current coming off the ac line connected to the charger? And keep in mind he is using a adapter with a regular extension cord that you would buy from home depot that is pluging directly into a guess battery charger that is hooked to 1 battery. ???????



On my boats I put a 2 circut breakers in the transome one on the positive coming off the motor and one on the negative coming off the motor. And I also have a daul battery switch. With daul batterys.

But when Im at the dock I disactivate the positive breaker and the negative breaker which basically is interupting a complete circut. It disconnects the motors positive and negative completly from the batterys. I then plug in the charger that is hooked up to both batterys.


Now The only thing hooked to those batt is the bilge pump and the acc control panel switch which is always turned off so thers no complete circut there as well... Also the battery switch is turned off so the acc panel dosent even have power to it. So the only complete circut on the boat is the bulge pump and the battery charger charging the batterys ......

Correct me if im wrong please, but Am I in the right for leaving the negative breaker disengaged as well as the positive while the boat is charging? Or should I leave the negative breaker on so the boat has direct ground to the engine block?


Because if this is the case i will tell my brother to buy a set of breakers and install them in his boat like I was doing. Or 1 breaker if what I am doing is wrong... ????? This is a subject that stumps me and confuses me everytime bc the boat is aluminum.....


All I know is after seeing his boat I do not want that to ever happen to my boat! Or any 1 elses.... it was upseting


Please help

DO NOT put a circuit breaker in the negative side of the circuit. If the breaker trips, everything is still "hot" from the positive battery post, through the load, and to the breaker.

To isolate the battery (like I posted above), you could put a switch in each side of the circuit (near the battery and near each other so you remember to operate both of them at the same time). The best solution would be a double pole switch to switch both conductors but I don't recall ever seeing a double pole marine battery switch.

Most circuit breakers are not designed to be used as switches. Using them as switches will wear them out prematurely.

 

[191Seanymphstriper]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

Ok but what you are saying is it is good to have both positive and neg disconected while charging right?

 

[191Seanymphstriper]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

Ok but what you are saying is it is good to have both positive and neg disconected while charging right ? Sotheres no direct connectiong with the boat? Is this correct?

 

[rwidman]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

Ok but what you are saying is it is good to have both positive and neg disconected while charging right ? Sotheres no direct connectiong with the boat? Is this correct?

That is correct. There is no connection from the actual boat to shore power. Even through the charger.

 

[191Seanymphstriper]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

Ok thanks for the help. I will install a another switch to cut all power in my boats and I will tell my brother he needs 2 switches etc! Thanks... P.S I also called black lab and a few other aluminum boat builders. They all said to mount another zinc to the transom below the water line directly bolted to the boat. They said the zinc on the outboard is not enough to protect the whole boat! So I guess i will be adding zincs on my boats as well so they dont look like my bros boat. I will also tell my bro about the zinc as well... Thanks for explaining it in simple terms. Thats what I had thought and thats why I have the huge breakers that would never trip. But just incase as you said, I will look into that and add a 2 way on off switch! Thanks for the input!

 

[Triton II]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

Since the ground side (negative cable) on the battery or batteries remains connected to the engine the hull is also at ground potential so disconnecting the positive side with a switch has no real advantage. Outboards become bonded to the hull with the bolts used to secure the engine to the transom. Perhaps everything you mention can have a bearing on corrosion. Perhaps the power wiring at the slip is also at fault.

SNS,

Silvertip is spot on with his post above. I makes not a jot of difference where the anode is as long as it's galvanically bonded to the hull and its in the water when moored/anchored - hence my argument against your "always put an anode on the hull" post in NB's thread. Here in Australia we use alloy boats in saltwater on a big scale (lots of boats per head of population and not much fresh water) and sure you can (and many do) put anodes on hulls however it doesn't mean the outboard bracket anode is wrong or ineffective - it isn't and most boat manufacturers here use a similar anode system as per my photo in NB's thread. It works and to say it doesn't is incorrect.

TII

 

[191Seanymphstriper]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

Ok after my last post I had called around several boat companys suck as black lab pacific skiffs basically the same company ,,, And 2 other companies and they too said If you are keeping your boat docked in saltwater! That the zinc on the bottom bracket of your motor housing that yes is connected to the boat is not be enough to stop electroylosis from eating your boat.

The manufacturer of the outboard company did not and does not put zinks on the outboard bracket (anodes) to protect your aluminum boat.

They put zincs on the motor to protect the aluminum housing on the motor. Will that zinc on your outboard also protect your boat????? Yes and no... Yes if your just trailering and using the boat in salt water etc yes,,,,,,,,,,,,,


If you are leaving the boat in water with a high rate of electroylosis NO NO NO!


The anode on that outboard bracket within 1 month will be eaten to shreds. But with a zinc attatched to the boat under the waterline and the outboard bracket you bet that both zinks will hold up better and for longer and The boat itself will be protected directly!

And you know what. If a 10K or 50K motor has its own anode. So should my boat... What is my boat not worth it? It sure is to me... The reason why lund starcraft etc never installed zincs on them is because most people use them on lakes and dont keep them in the water, they trailer them...


And triton your boat looks way to clean to have been kept in salt water for 3 months strait especailly with no bottom paint on it at all... You may have used the boat 3 months strait in salt water but it diddnt sit for 3 month in salt water it was deff trailered! Otherwise you would have a scum line, water line, Your outboard bracket wouldnt be that clean etc. The livewell ports would be a little discolored etc etc etc etc

 

[Triton II]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

Ok after my last post I had called around several boat companys suck as black lab pacific skiffs basically the same company ,,, And 2 other companies and they too said If you are keeping your boat docked in saltwater! That the zinc on the bottom bracket of your motor housing that yes is connected to the boat is not be enough to stop electroylosis from eating your boat.

The manufacturer of the outboard company did not and does not put zinks on the outboard bracket (anodes) to protect your aluminum boat.

They put zincs on the motor to protect the aluminum housing on the motor. Will that zinc on your outboard also protect your boat????? Yes and no... Yes if your just trailering and using the boat in salt water etc yes,,,,,,,,,,,,,


If you are leaving the boat in water with a high rate of electroylosis NO NO NO!


The anode on that outboard bracket within 1 month will be eaten to shreds. But with a zinc attatched to the boat under the waterline and the outboard bracket you bet that both zinks will hold up better and for longer and The boat itself will be protected directly!

And you know what. If a 10K or 50K motor has its own anode. So should my boat... What is my boat not worth it? It sure is to me... The reason why lund starcraft etc never installed zincs on them is because most people use them on lakes and dont keep them in the water, they trailer them...


And triton your boat looks way to clean to have been kept in salt water for 3 months strait especailly with no bottom paint on it at all... You may have used the boat 3 months strait in salt water but it diddnt sit for 3 month in salt water it was deff trailered! Otherwise you would have a scum line, water line, Your outboard bracket wouldnt be that clean etc. The livewell ports would be a little discolored etc etc etc etc

SNS. This is utter boloney mate. Sure, more zincs the merrier - however that zinc, as stated before, connected to the boat's hull via the through bolts and to the trim/tilt via the stainless wire. To tell all alloy boat owners that they NEED to attach zincs to the hull is UTTER crap. The less holes in your hull the better. Finally, I never stated the boat was moored for three months, I stated the boat's been in saltwater for three months over two years - I keep a log.

TII

 

[191Seanymphstriper]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

SNS,

Silvertip is spot on with his post above. I makes not a jot of difference where the anode is as long as it's galvanically bonded to the hull and its in the water when moored/anchored - hence my argument against your "always put an anode on the hull" post in NB's thread. Here in Australia we use alloy boats in saltwater on a big scale (lots of boats per head of population and not much fresh water) and sure you can (and many do) put anodes on hulls however it doesn't mean the outboard bracket anode is wrong or ineffective - it isn't and most boat manufacturers here use a similar anode system as per my photo in NB's thread. It works and to say it doesn't is incorrect.

TII

Ok I never said that it diddnt work. what I did say is that it will better protect your hull! And just to let you know there isnt a outboard made without a zinc (anode) on it... Y???? To protect the aluminum from electroylosis.



So if you have a aluminum boat. It 2 should have a zinc (anoyde) on it


And they sell special anodes for fresh water versus salt water...


And Im not saying that the anode on the outboard bracket dosent work...

Because it did. It got eaten right off my brothers outboard and then attacted the boat....


Now if he would have had a anode on the boat and the outboard both zincs would have gotton hit at the same time thus lasting a longer period of time because the electroylosis would have been eating 2 anodes instead of 1... And that would take longer....

Also i am just thinking that if you do own a aluminum boat no matter how big or small they all really should have zincs on them to protect them at all times from electroylosis...


And after speeking to a couple of alloy boat builders this is why they do it! To have the boat better protected... Plate boats are usually bigger heavier and harder to trailer and most who own them keep them in the water.. So thats why they do this!



Also electroylosis is found most at the dock when around elec shore power and other boats electrical systems etc


So if you trailer you can have the same anode zinc on that outboard bracket for years without needing to replace it!


But if kept in water a month maybe 2 and its eaten up totally......

 

[191Seanymphstriper]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

As I thought! You never moored it in salt water...


And you could bolt it threw hull... But I would just weld aluminum bracket off the transom like the pacific skiffs have... So no holes in the boat.... Just 2 welds... And sry you think its crap. But i think if you have a nice painted aluminum boat and you are mooring it ... YESSSSSSSSSSSS YOU SHOULD MOUNT ANOTHER ANODE TO YOUR RIVETD OR PLATED ALUMINUM BOAT!!!!

 

[Triton II]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

I'm saying that to state all alloy boat owners need an anode on the hull is crap. My boat is 5mm plate 5083 alloy and doesn't have or need an anode attached directly to the hull because it has four motor zincs and the larger boat/bracket zinc which do a wonderful job of protecting the boat, bracket and motor. I started to argue with you because of your original post in NB's thread which said:

Put a zink on her attatched right to the hull bellow the water line. I know you are not going to be leaving her in the water, but just do it for precaution. My brother has had some serious issue with his 18 cc starcraft and it really upset me to see it looking the way it did. So just for precation its a good idea..

And for all you other tinny owners you should all do the same! Alum is very funny.

I'm merely saying that statement is, in my opinion, incorrect and I think my boats condition after two years of use weekend in, weekend out all year round, is testament to that. Thanks for the opportunity to set the record straight.

TII

 

[191Seanymphstriper]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

I think if you are or docking or as you say mooring the boat then the zincs on your outboard are not enough especially when you are leaving the boat plugged into a dockside powerline and are running a charger etc...


But if you are trilering your bueaty queen then the zinks on your outboard should be ok... Because there is no electroylosis on land above water! But I still think that all aluminum boats should have zinks on the aluminum hulls hull.

Because most outboards have trim and come out of the water. yet the bracket is under the water line still when docked.

Even though the outboard is mainly kept out of the water other then use it is protected.



( BUT FOR A ZINC (anode) TO PROTECT YOUR BOAT IT (the zinc) MUST BE UP AGAINST BARE UNPAINTED ALUMINUM (the boat)! AND THATS A FACT!


So your motor may have a zinc on it but if the pritty motor is sitting on a nicly PAINTED transome With your nice shinny new bolts on the inner transom against your nicly PAINTED inner motor bracket where the bolts screw down then HOW MUCH OF THAT Zinc is really protecting your boat on that motors zinc,,,???????



I think you my friend are wrong!

I think to fully protect your aluminum boat from electroylosis you should have a HULL MOUNTED ZINC iether directly bolted or A unpainted aluminum bracket on a unpainted spot on your transon below the water line.....


Thats why they say do not paint the zincs (anodes) at all and do not paint where they are mounted!!!!!!!!!!!!!!!!!


And further more your nicly painted outboard when you remove your zincs to change them you will see bare aluminum unpainted flat spots where the zinc gets mounted to on the outboard bracket and is tightened down to....


So you explain to me how your little zincs are protecting your fully painted inside and out boat and your painted motor bracket is connected to your painted boat and your large stainless screws are going threw your PAINTED holes in your painted outboard bracket?

 

[191Seanymphstriper]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

I'm merely saying that statement is, in my opinion, incorrect and I think my boats condition after two years of use weekend in, weekend out all year round, is testament to that. Thanks for the opportunity to set the record straight.

TII

You said it! Just your opinion! And the reason why your boat looks so good is because its still fairly new, and its a trailer queen! And prob garge kept or carported etc.... And also because she was never kept in the water EVER for a long period of time ,,,,,, And that has nothing to do with your zincs or (anodes) keeping your new boat looking like new..

The reason why she looks that way is bc of whats stated above........


And the only record you set strait here was that you have an opinion! As we all do!

 

[rwidman]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

If you want to protect your hull, the best bet is to attach one or more anodes to the hull.

While the motor is bolted or clamped to the hull, it may not make good electrical contact because of sealant or corrosion. Also, the motor anode is sized to protect only the motor. Rather than take the chance, anodes attatched directly to the hull are the best plan.

The point about different anodes for salt, brackish, and fresh water is a valid point. Be sure you have the correct anodes for the water you typically boat in.

 

[191Seanymphstriper]

Re: ? About bottom paint on aluminum , electrolysis , Charging , Repairing elec damag

Thank you! Thats what i was saying and thats what i have always believed and done. I had also called up and asked around yesterday to be sure. So thanks for confirming My theory....