Are these for electrolysis ??

[MAW31]

I've often wondered what these 'rock' type extensions are on my boat.

I'm guessing they have something to do with electrolysis but i'm just guessing.

If they are, am i better served by cleaning them??

thanks

 

[robert graham]

Re: Are these for electrolysis ??

They're zinc or aluminum sacrificial anodes and you could clean that corrosion off with a wire brush. Might be good to remove each one to clean it and it's contact surfaces with boat/motor. Looks like they've been in salt water? Good Luck!

 

[dingbat]

Re: Are these for electrolysis ??

They are beyond shot. They need replaced.

 

[MAW31]

Re: Are these for electrolysis ??

beyond shot? What makes them 'shot' ? Won't the electrolysis process continue to work until the blocks are gone?


does this explain the fuzzy gunk thats appearing on the motor surface ?

 

[Home Cookin']

Re: Are these for electrolysis ??

I htink fuzzy gunk is from electrolysis; if it appears overnight you may have an electrical "leak". Happened to me once when I left the key on overnight by accident.
I assume they are "shot" because the surface is all corrosion no zinc, so it can't work any more. Likewise if the connection with the motor is so corroded, it's like a corroded battery connection.

 

[MAW31]

Re: Are these for electrolysis ??

well ok.

i got 1 off the other feels like i'm gonna break the bolt.

This looks like a place where siezed bolts might be a common problem.

for now, i can get 1 replaced.

should I try to 'crush' the block so i can gain access to the base threads and work em with WD40 ?

 

[dingbat]

Re: Are these for electrolysis ??

The amount of protection a zinc anode provides depends on its surface area. The zinc surface area needed varies but you can use 1% of the surface area of the protected metal as a starting point.

If the surface area is reduced so it the protection level. Zincs should be replaced when about half of the anode has been lost to corrosion.

 

[rodbolt]

Re: Are these for electrolysis ??

see the color, means they have calcified and are just another piece of metal along for the ride. NEVER clean a zinc or AL anode with a steel wire brush. clean with 60 or 80 grit sand paper not carbide paper.
wire brushs can transfer steel to the anode surface rendering it useless.
we see anodes like the one in your picture mostly on trailered boats. about 5 wet and dry cycles the anode calcifies and quits being a sacraficial anode,its whole purpose in life is to sacrifice,go away,dissapear even.
if they dont dissapear they simply are not working either due to that white scale or loss of bonding to the metal its supposed to protect.