Changing a zinc anode in-between tides

[Rhylsailer99]

I don't. think its worth a lift out just to change an anode, so I am thinking next season to just attempt this job in between tides.
I did a good job with the anti foul this summer that way, but I think I will have to get some butyl tape ready in case I need to change the bolts.
The bolts were only replaced in 2021.

 

[Plum]

I don't. think its worth a lift out just to change an anode, so I am thinking next season to just attempt this job in between tides.
I did a good job with the anti foul this summer that way, but I think I will have to get some butyl tape ready in case I need to change the bolts.
The bolts were only replaced in 2021.

I always keep a pair of anode studs on board, plus some mastic. Unless your zinc has wasted away completely you should not have a stud corrosion problem. The bigest problem I have had is with a stud rotating when removing or refitting the anode which can break the seal/bond of the stud. This then takes a long time to reseal having to move between inside and outside the boat a few times if singlehanded. I have now overcome that by drilling 2 x 11mm holes in s strip of stainless steel, drop this over the two studs inside the boat, add another nut to each stud and while holding the lower nut with a spanner tighten the new top nut very tight against the stainless strip so locking the studs to it. Alternatively, if you have studs with a square outer washer welded on, as opposed to round ones, and you have a wooden hull, you can cut a square recess on the planking to stop the rotation.

 

[Tranona]

I don't. think its worth a lift out just to change an anode, so I am thinking next season to just attempt this job in between tides.
I did a good job with the anti foul this summer that way, but I think I will have to get some butyl tape ready in case I need to change the bolts.
The bolts were only replaced in 2021.

If this is a hull anode protecting your propeller then it should last far more than one season. Do you have a historic usage pattern that indicates life?

But to answer your question, yes, you should be able to change it easily between tides.

 

[Rappey]

Many of us can dry out, scub and pressure wash the hull, antifoul the boat and change the anodes in one tide. Its probably very dependant on fitness levels.

 

[alan_d]

Many of us can dry out, scub and pressure wash the hull, antifoul the boat and change the anodes in one tide. Its probably very dependant on fitness levels.

.... and possibly the tidal range?

 

[pandos]

Many of us can dry out, scub and pressure wash the hull, antifoul the boat and change the anodes in one tide. Its probably very dependant on fitness levels.

I did that a few years ago...when I got home I had a call from a cardiologist to say I needed a triple bypass (CT done a few days earlier).

Not sure that it takes too much fitness, more a case or organisation and stubbornness.

I use a vice-grips jammed in place on anything that may twist when working alone

 

[Dellquay13]

.... and possibly the tidal range?

AIUI, no matter the range, the tide is only out for the period in the tide tables, it can’t take more or less time, only the rate of rise or fall can change.

 

[Neeves]

Its probably very dependant on fitness levels.

and, maybe, the size of the yacht?

We often dried out with our cat and not knowing what unexpected problem might develop we would plan on staying through tides (and provision accordingly). We would drop the bower anchor at an appropriate location reverse in until we grounded, leave the engines running gently in reverse and dinghy out a, prepared, stern anchor from each transom. Then tighten the stern rodes.

Clean down the hull before the fouling dries out - it means wading through water, we drew 1m - we used waders.

Having 2 keels makes it all possible

If you are leaving at night, it helped us to beach bow out, rather than reverse out.

Jonathan

 

[alan_d]

AIUI, no matter the range, the tide is only out for the period in the tide tables, it can’t take more or less time, only the rate of rise or fall can change.

Yes, I agree that the times between successive high waters (say) will be the same whatever the range, but the ability to actually do things beyween tides is affected by how far away the water moves. Consider the examples of tidal ranges of 50 cm. compared with 5 metres - do you think you would be able to complete the same sort of jobs in each case?

 

[Dellquay13]

Yes, I agree that the times between successive high waters (say) will be the same whatever the range, but the ability to actually do things beyween tides is affected by how far away the water moves. Consider the examples of tidal ranges of 50 cm. compared with 5 metres - do you think you would be able to complete the same sort of jobs in each case?

In theory such a wild tidal range could affect the work you could do, although it would take the same time to rise 50cm as it would 5m, if that was the variation in tidal ranges on different days, but I haven’t heard of anywhere that has a spring range 10 times greater than it‘a neap range. I would guesstimate the typical spring to neap ratio being about 1.4 times greater at springs.
Springs and Neaps do affect some things of course, the boat hoist at Milford Marina can’t handle deep fin boats at neaps when there is insufficient depth on the slip at HW. The tidal ranges there are typically 5m at neaps and 7m at springs, a ratio of about 1:1.4? This proves your point for a fixed position, but a twin keel boat can choose where it dries out.

 

[Rhylsailer99]

It is a bilge keel and on the mooring spends more time sat on its keels than it does floating. I will just make sure I have some sikaflex and spare anode bolts/nuys just in case.

 

[alan_d]

In theory such a wild tidal range could affect the work you could do, although it would take the same time to rise 50cm as it would 5m, if that was the variation in tidal ranges on different days, but I haven’t heard of anywhere that has a spring range 10 times greater than it‘a neap range. I would guesstimate the typical spring to neap ratio being about 1.4 times greater at springs.
Springs and Neaps do affect some things of course, the boat hoist at Milford Marina can’t handle deep fin boats at neaps when there is insufficient depth on the slip at HW. The tidal ranges there are typically 5m at neaps and 7m at springs, a ratio of about 1:1.4? This proves your point for a fixed position, but a twin keel boat can choose where it dries out.

I was not implying that these ranges could be found in the same place, merely that tidal range might be something to take into account when judging whether or not the proposed plan was feasible. I was using tidal range in its normally-understood meaning of the difference of height between successive high and low waters; you seem to be thinking about the difference between Spring and Neap ranges.