Saildrive anode

[mick]

I have a Penta D20 with 130S saildrive. Last season's anode is still in place and is only partially worn (perhaps 75% left). The boat has been in the yard since last September. Can I leave the anode in place for the coming season?

 

[Tranona]

Yes. Make sure the fastening screws are still tight.

 

[VicS]

I have a Penta D20 with 130S saildrive. Last season's anode is still in place and is only partially worn (perhaps 75% left). The boat has been in the yard since last September. Can I leave the anode in place for the coming season?

As Tranona says

Do you have prop anodes as well.

The one on the sail drive behind the prop protects the saildrive.

Prop may or may not be protected by its own anode(s) depending on make and type.

 

[mick]

As Tranona says

Do you have prop anodes as well.

The one on the sail drive behind the prop protects the saildrive.

Prop may or may not be protected by its own anode(s) depending on make and type.

The prop is a Flexofold 2-blade, which doesn't have an anode. I'll just leave the saildrive anode in place then. Thanks, Vic (also to Tranona).

edit: Forgot to ask. Should I wirebrush the anode or do anything else to it?

 

[Stork_III]

The prop is a Flexofold 2-blade, which doesn't have an anode. I'll just leave the saildrive anode in place then. Thanks, Vic (also to Tranona).

edit: Forgot to ask. Should I wirebrush the anode or do anything else to it?

Good idea to clean up. Some say wire brushing leaves bits of steel on/in surface and accelerates anode loss. I use an anglegrinder with coarse disc to get bright zinc.

 

[Sailfree]

This anode used to corrode extensively on the hamble and often came completely loose.

I found the solution was to cut down some c/s screws with allen key head so they can be really tightened up. I am suprised only partially eated I would check for continuity between the anode and prop and saildrive leg.

No continuity no protection.

 

[Tranona]

This anode used to corrode extensively on the hamble and often came completely loose.

I found the solution was to cut down some c/s screws with allen key head so they can be really tightened up. I am suprised only partially eated I would check for continuity between the anode and prop and saildrive leg.

No continuity no protection.

The 130 anodes are different from the earlier type, being in 2 halves and don't suffer from the same problems of erosion around the fixing screws.

 

[sailaboutvic]

Mine normally last two years , may be because we don't use marinas for 8 months of the year , what does wear are the three around the prop ,

 

[VicS]

Mine normally last two years , may be because we don't use marinas for 8 months of the year , what does wear are the three around the prop ,

You'd expect the prop anodes do be consumed failry quickly as they are fixed to a prop, which is presumably a mainly a copper alloy, with a fairly large surface area. Depending on the exact alloy of the prop there will be a emf of something in the region of 0.7 volt driving the process.

The anode on the saildrive is protecting the aluminium alloy which is largely covered with a protective coating anyway and there will only be about 0.2 volt driving the consumption of it.

Rapid depletion of the sail drive anode, if it occurs, should start alarm bells ringing because if that goes the next in line is the leg itself!

 

[mick]

You'd expect the prop anodes do be consumed failry quickly as they are fixed to a prop, which is presumably a mainly a copper alloy, with a fairly large surface area. Depending on the exact alloy of the prop there will be a emf of something in the region of 0.7 volt driving the process.

The anode on the saildrive is protecting the aluminium alloy which is largely covered with a protective coating anyway and there will only be about 0.2 volt driving the consumption of it.

Rapid depletion of the sail drive anode, if it occurs, should start alarm bells ringing because if that goes the next in line is the leg itself!

Vic, thanks for that. What would you do to prepare the saildrive anode before launch?