What bits to antifoul?

[sighmoon]

Please excuse the stupidly obvious question, but do you antifoul everything under water?

In particular, what about the anode - will it still work if painted?

What about the paddle wheel log and echo sounder transponder? I would have thought so, but neither have any paint on them at the moment.

 

[tcm]

no, you don't antifoul the anode - it has to stay raw to do the electroylis thing so it gets eaten instead of the more valuable things. You shd replace the anode if more than half eaten.

 

[Wansworth]

Whilst your at it make sure the anode is properly touching and boltedon tight,metal to metal.

 

[twisterkai]

Technically, if the paddle wheel & echo sounder transducer are plastic, you should antifoul them with a water based antifoul. Apparently, the solvents in conventional paints can damage the plastic. Anyone bother with that? Personally, I've never bothered - The paddle wheel is always removed when not in use (whatever antifouling's on it, it still stops working after 3-4 wks) and the echo transducer I can reach with a long handled deck brush from dinghy, so it gets a scrub when it needs it.

 

[Evadne]

and another thing..

There are usually 2 or 3 debates per month at this time of year on whether it is better to antifoul the propellor, or to polish it, or to coat with anhydrous lanolin. Opinion is apparently divided about equally on those, tho' polishing a prop. is probably only effective if it is a bronze one. Oh, make sure you use the correct antifoul on aluminium (outdrive legs, that sort of thing).

 

[andy_wilson]

Anodes!

Given that zinc has gone up in price 10 fold, I think I might anti-foul mine to make them last a bit longer.

Surely the copper in the a/f paint will start to erode instead.

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OK, only kidding.

I'm not anti-fouling anything this year, waste of £100 and 5 hours DIY labour. Gonna dry out in June for a scrub (2-3 hours labour) to see how things are going on and take a view then. My A/F has started to get a bit thick anyway so a couple of scrubs should get it back to a reasonable coating. Last time I did this I got close to the epoxy peeping through in a few places.

In answer to your question, if you must, give the hull, keel, rudder 1 or 2 coats as per the directions. Use any spare on the pointy bit of the hull, around the waterline to a depth of 30cm and on the p-bracket and leading and trailing edges of the keel and rudder, all of which have a bit more water action to erode the coating.

Do not paint anodes, metal skin fittings without using suitable primer first, or the echo sounder transducer face.

I have used the boot topping (hard) A/F on my log wheel in the past but it did no better than when simply scraped and scrubbed clean.

Little point putting A/F on shaft or propellor, mine seem to last longer polished, though some advocate the use of sheeps droppings or similar on the prop.

If I A/F in the summer I think I will try Chilli powder in the mix. Anthing has to be better than the stuff that comes in the tins. When I suggested to my yard that they uphold the sales of goods act if I buy some off them they said my original plan sounded very feasable!

Remember James Jermains recent report on his patchwork bottom. The telling comment was that some areas of the previous years A/F - between the patchwork of brands on test - had less fouling than the more recent stuff.

 

[sighmoon]

Re: Anodes!

Thanks guys.

I didn't realise the contact was so critical for the anode. I have one on the prop shaft, which I thought would suffice, but I don't have one on the cast iron keel. Should I?

 

[billmacfarlane]

If you have a saildrive don't use a copper based antifoul on it. Use a metal free one such as Trilux.

 

[Evadne]

Re: Anodes!

If the boat is of any age and there isn't one already, then I wouldn't bother, although it wouldn't do any harm. An anode is put in place to protect a piece of metal from corroding because a more noble piece of metal is nearby. Your keel is not very noble, even when covered in antifouling, but I'd be surprised if it's in any real danger of corroding away. FWIW my boat's exposed cast iron keel has survived without any anodes for the last 40-odd years.