galvanic corrosion from motor?

[fishon]

hi guys just wandering for those who have alloy boats with outboards connected to the battery how do you stop the negative

running thru the hull i havent done this yet but just wanted some opinions of people

that have gone thru this or not and what are your thoughts

cheers guys

[smithy744]

every negative ground connection is run back to the battery . never contected to the hull

[fishon]

every negative ground connection is run back to the battery . never contected to the hull

yeah but negative current runs thru the motor which is connected to the transom thats why i was askin does every body isolate

it somehow? just hard as there is 4 bolts to somehow isolate to that run thru the transom?

[fishon]

also if you do isolate the engine will it be a waste of time

whilst in the water will the water just conduct it straight back to the hull?

[dogtooth]

Hi Fishon ,

The only time you can isolate it is when your battery isolator is off , in other words when your not using your boat . All starter motors are earthed to the engine , so if your engine is bolted to alloy or metal , your hull is earthed zzzz. Just keep your anodes on the motor up to date to avoid electrolosis in your hull .

Cheers Dogtooth...... John.....

[fishon]

Hi Fishon ,

The only time you can isolate it is when your battery isolator is off , in other words when your not using your boat . All starter motors are earthed to the engine , so if your engine is bolted to alloy or metal , your hull is earthed zzzz. Just keep your anodes on the motor up to date to avoid electrolosis in your hull .

Cheers Dogtooth...... John.....

thanks mate i got an isolator on my positive might have to put one on the negative i was going to isloate the complete motor from the hull but im thinkin the water will just direct it straight back

im guessing well i know this must be a common occurance

just that ive heard alot of threads stating that bus bars that are earthed directly to the hull is disasterous

abit confusing

thanks for your reply dogtooth cheers

[Fester]

No need to isolate possitive and negative, so long as one side is cut, then circuit is incomplete!

[fishon]

after fitting my shift cables the other day i was talking to the guys down at ****** marine

and told them i had negative current running thru my hull

they gave me quite a weird look and said that aint right

got my test light out and showed them and they were shocked told me to isolate them straight away

what i was most amazed by is that theres millions of tinnys out there and theyve never heard of it before