Some boats ground the tank only but the better arrangement is a ground wire to the tank and then a wire from there to the sender flange tab. It is important for a metal tank to be grounded for several reasons; galvanic action is one.
fuel gauge
- Thread starter Gibsonsky
- Start date
Yea.. cant confirm where the ground wire goes. Thinking I may cut and attach to philips ground screw
Since you grounded the pink wire at the sender, you know the tank is grounded. You're good. Don't cut the ground wire - if you want, add another ground wire.
blindmullet
Well-Known Member
My tank builder recommended installing a zinc just to be able to check when your tank is being attacked. Thought it wasn't a half bad idea.
I was thinking about that, too. I suppose something like a round trim tab zinc could be used. Use the sender hole as access and drill a hole to use a through bolt. I'm just not too keen on drilling holes near huge vat of gas fumes!
But, I wonder how accurate of a "test" the anode would actually be? I mean, there's always moisture around a tank so the anode would naturally wear away just from the fact it is in contact with a more noble metal (the tank).
A zinc anode is less noble than the aluminum tank but for it to sacrifice itself to protect the tank it is attached to, both items must be submerged in an electrolyte. Seawater is a good one. In the air though the zinc can't become sacrificial because an electric charge can't envelope it. I think hooking a ground wire direct to the battery negative is as good as you can do on our small boats. I think what kills our aluminum tanks is corrosion pitting not electrolysis.
Actually, air is still an electrolytic solution - just less of one that fresh water, which is less of one than seawater. Galvanic corrosion still happens in air - the warmer/moister the air, the faster it will happen. Just a little side point, there!
blindmullet
Well-Known Member
The zinc isn't sacrificial like on a motor. The zinc would be attached to the tab via a bonding wire. It could be positioned so you could check the zinc without removing hatches. IMO, this would be better with tanks that are foamed in. I'm doing my little boat right now and might give it a shot to see if it's practical.