Drilling holes for Annodes on Iron keels.

[Binman]

Just before I floated my Pandora 700, I brought a matching pair of Annodes European brand, there had been one previously fitted, all that was left was the bolts on one keel only. So I set my 240volt Drill brought some drill bits 1/8 th to 1/2inch, made a start but they kepted breaking, speed was right drills brand new, what might have I done wrong, When it comes out next year I'm going to hire a mag drill and clamp it to keels then use core cutters, I'm amazed just how hard the metal was.

 

[Tranona]

Why would you want to put anodes on an iron keel? There is virtually no chance of any galvanic action on an iron keel as it is just iron - there needs to be two metals in contact in seawater with one more noble than the other - for example a stainless shaft and prop with a high zinc content where the anode will erode in preference to the prop.

Most corrosion on iron keels is simple straightforward rust and the only way to reduce it is to blast the castings clean and coat them in epoxy or a dedicated protective paint system to stop the seawater from causing rust.

 

[longjohnsilver]

Why not weld them on?

 

[oldsaltoz]

If it is cast iron there is good chance you are hitting voids or contamination.

Cast iron is considered porous and often even has sant from the mold trapped.

Good luck and fair winds.

 

[Niander]

did you use cobalt drill bits?

 

[sailorman]

Just before I floated my Pandora 700, I brought a matching pair of Annodes European brand, there had been one previously fitted, all that was left was the bolts on one keel only. So I set my 240volt Drill brought some drill bits 1/8 th to 1/2inch, made a start but they kepted breaking, speed was right drills brand new, what might have I done wrong, When it comes out next year I'm going to hire a mag drill and clamp it to keels then use core cutters, I'm amazed just how hard the metal was.

WHY, do you think that the cast iron keel requires anodes

 

[Binman]

Hi, no just Metal drill bits, I thought they would work.

 

[Binman]

Hi, that is a good question, I did look on line but couldn't find a definitive answer, in my boat yard some were for and some did say don't bother, being new to owning my own boat, I must admit I didn't know what way to go, I fitted a new one to the outboard though.

 

[sailorman]

dont waste beer vouchers on anodes :encouragement:

 

[pvb]

You don't need anodes on a keel. The fact that there was one fitted by a previous owner is immaterial.

 

[sailorman]

nowt as strange as " a previous owner"

 

[pvb]

They certainly have some odd ideas!

 

[Sniper]

Am I right in inferring that you have a bilge keel model? Another vote for 'forget the anodes'. I had a b/k Pandora myself many years ago and had a lot of fun with her. The only issue with the keels was that they occasionally got caught in the rope mooring riser; on one occasion she lifted the mooring out of the mud and trundled across the river with it. They don't rust any more than any other cast iron keel.

Picking up on another thread, a 6hp o/b will be more than adequate; I managed well with a 4hp long shaft on mine.

 

[VicS]

Hi, that is a good question, I did look on line but couldn't find a definitive answer, in my boat yard some were for and some did say don't bother, being new to owning my own boat, I must admit I didn't know what way to go, I fitted a new one to the outboard though.

dont waste beer vouchers on anodes :encouragement:

But replace the one on the outboard regularly especially being in a well and presumably always immersed. Even consider bolting an additional one onto the anti-ventilation plate


If the keels needed anodes you would have to fit one on each side of each keel !

 

[Binman]

Hi, one thing I'm going to do when I have the boat out in March, is to get the measurement from the transom to the bottom of the keels then I will have a better idea of what length shaft to get on the engine, can only be either ,long or U/l, because the engine sits in a well it's impossible to lift/tilt it. I brought it last feb, done quite a lot of work on it, If I do have to buy another engine it's still going to be a cheap seasons sailing for a few seasons, only Antifouling to do.

 

[Tranona]

Hi, one thing I'm going to do when I have the boat out in March, is to get the measurement from the transom to the bottom of the keels then I will have a better idea of what length shaft to get on the engine, can only be either ,long or U/l, because the engine sits in a well it's impossible to lift/tilt it. I brought it last feb, done quite a lot of work on it, If I do have to buy another engine it's still going to be a cheap seasons sailing for a few seasons, only Antifouling to do.

Very much doubt you need an extra long shaft. The measurement you need is from the top of the mounting board to the static waterline. It will probably be about 20" which is the nominal dimension for a long shaft. You can measure while it is in the water. The depth of keel is largely irrelevant, you need the leg immersed just enough to cover the plate above the prop. Extra long shafts are usually specified for boats where the transom is very high and the engine is mounted on the transom or a bracket. The extra length means the power head is higher when the drive part of the leg is immersed to the correct level - not to get the prop deeper in the water.

 

[sailorman]

There is an engine for sale in Burnham-on=Crouch 2 careful owners ( @ the same time)

 

[Binman]

Very much doubt you need an extra long shaft. The measurement you need is from the top of the mounting board to the static waterline. It will probably be about 20" which is the nominal dimension for a long shaft. You can measure while it is in the water. The depth of keel is largely irrelevant, you need the leg immersed just enough to cover the plate above the prop. Extra long shafts are usually specified for boats where the transom is very high and the engine is mounted on the transom or a bracket. The extra length means the power head is higher when the drive part of the leg is immersed to the correct level - not to get the prop deeper in the water.

Thank you very much for your Wisdom, Its like many things, you cannot beleive every thing you are told. Why did the previous owner fit such a long shaft, was he worried the prop would come out the water on certain manoeuvres, As it is its low to the water sitting in the well, Agree on what you are saying, still need to get my engine repaired, i have got electric start with remote, got tiller on the boat, thats how it is set up. Could get a second engine long shaft as standby. I have one in my garage but that needs new rings, that a 6hp two stroke Yamaha again, At least i can lift the 6hp.Taking the 9hp out for a service is hard work with the shaft being ultra long, you have to lift it right up untill the prop is level with the transom before you can tip it over. The Carb does appear to be the problem, its been taken off twice and ultrasonic cleaned, will tick over lovely but as soon as you try to excelerate just bogs down. Think contaminated fuel left in the carb for so long has done it no good at all.

 

[GrahamHR]

Thank you very much for your Wisdom, Its like many things, you cannot beleive every thing you are told. Why did the previous owner fit such a long shaft, was he worried the prop would come out the water on certain manoeuvres, As it is its low to the water sitting in the well, Agree on what you are saying, still need to get my engine repaired, i have got electric start with remote, got tiller on the boat, thats how it is set up. Could get a second engine long shaft as standby. I have one in my garage but that needs new rings, that a 6hp two stroke Yamaha again, At least i can lift the 6hp.Taking the 9hp out for a service is hard work with the shaft being ultra long, you have to lift it right up untill the prop is level with the transom before you can tip it over. The Carb does appear to be the problem, its been taken off twice and ultrasonic cleaned, will tick over lovely but as soon as you try to excelerate just bogs down. Think contaminated fuel left in the carb for so long has done it no good at all.

Regardless of whether you need anodes or not, are you sure the keel is made of cast iron? Not wrought iron ? Cast iron is usually the most easy iron alloy to drill.

 

[Norman_E]

Regardless of whether you need anodes or not, are you sure the keel is made of cast iron? Not wrought iron ? Cast iron is usually the most easy iron alloy to drill.

Not always as easy as it should be. If the surface of a casting is chilled it can be almost glass hard. That usually happens on small castings where the metal cools too quickly, and plough shares were traditionally made by casting the metal so that one side of the blade was chilled leaving the other side softer, thus making it self sharpening in use. The other issue is contamination. If the casting is made from iron which was not sourced from pure iron ore, but included scrap iron its composition might be variable and if some scrap steel was included in the mix a casting with hard patches could easily result. My own iron keel has anodes at the trailing edge, and they do get slowly used up.