reuse zinc?

[johngus]

just curious to see how many people replace the big zinxc on the transom every year.The one on the boat has 2 seasons on it and is still more then half.any reason why it needs to be changed every year?

 

[Lazy Daze]

Replacing anodes is not related to time. Anode condition is the sole factor. If it's about half way gone, replace it.

Any corrosion issues with your drive?

 

[Four Suns]

Any corrosion issues with your drive?

Seeing as he has inboards, the drive is probably fine.

 

[Go Aweigh2452]

After it is half gone, you need to replace them... Some newer ones have a plastic red or orange tab that when exposed, the zinc should be changed out. You could make your zinc more "active" by using a stainless steel wire brush on them. That would expose more of the good metal to the waters... But as long as you have more than half left, leave them... I would look at boatzincs.com or defender.com for replacements... Sounds like the end of this year is the time to replace...

 

[Henry Boyd]

'Zincs' work by converting the base metal to oxide (zinc, aluminum, magnesium depending on type). Ideally the oxide then flakes off and fresh material is exposed to the water. The issue would be whether the anode has become coated with an oxide layer. If it has then the oxide will act as an insulator and stop working. Remember anodized aluminum is just aluminum that has had the surface oxidized by electrolysis in an acid bath. If the anode has a white coating on it, but plenty of meat, you might want to pop it off go over it with emery cloth and get it down to bare metal.

Henry

Doug types faster the I do

 

[Lazy Daze]

Seeing as he has inboards, the drive is probably fine.

Ha! Good point!

 

[johngus]

I'm gonna hit it with a wire brush to get it fresh.figured I could get another year out of it,thanks for the replies.

 

[Redhook98]

We have some pretty flaky power issues at my marina. I replace them every year just for peace of mind, and so I can inspect the bottom. It's cheap insurance when it comes to replacing expensive running gear.

 

[Asureyez]

Cleaning the zinc periodically is a good idea for more even sacrificial action, but also to build up an base of observed knowledge of the progression of loss. Your boat will probably have a 12# - 20# slab hung on the back. and if you loose 6# of zinc in a season, I'd say the situation is very active and causes should be investigated.

Replacing the zinc at the half way mark is to also prevent its loss due to loosening around the attachment bolts. When loose it will not be as effective, perhaps not at all.

It seems wasteful, but it is there to prevent much larger and more costly damage.

 

[buddymac]

The zinc block sacrifices itself for the steel/brass on your boat, as it is higher on the galvanic scale then steel or brass. It is important that it has good contact with the bolts or metal otherwise the zinc sacriface will not take place. Instead the other metal piece (engines, coolers, etc) will corrode.