Anodes

[bluefinch]

I am trying to make my own anodes as I have a steel boat and need a dozen of the large size. Not having much sucess melting them down on the stove. Does any one know the melting temperature and how this can best be achieved or if practibable?

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[Safran]

If zinc casting alloy then 375-400 deg C depending on the aluminimum content. Assume you are not melting magnesium alloy, needs a slag or inert cover gas and considerable care and melts in the 630 deg C range.

It is important to preheat all ladles and moulds above boiling point to remove all moisture - any water leads to an impressive explosion.

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[longjohnsilver]

Yes, be very careful, a good friend of mine was almost blinded when melting lead to make diving weights.

Mind you he shouldn't really have been using the church roof!! ;-))

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[chasroberts]

There was an article about this in one of the sailing mags about 18 months ago. Sorry, can't be more specific than this but a trawl of PBO, Sailing Today or Yachting Monthly websites might turn something up.

Basically, they were suggesting melting old partially eroded Zinc anodes in a tin on top of a camping gas stove or similar and then using one of those bricks with the hollowed out sides as a mould. Please don't take my word for though and have a look at the websites. All seems a bit dodgy to me but as far as I remember they didn't seem to be making too big a deal of doing it other than you obviously have to be careful when handling molten metal!!!!

Good luck

Chas

<hr width=100% size=1>Semper in excretum sum. Sole profundum variat!

 

[CharlesM]

... and of course it is probably not neccesary to point out the fumes can be poisoness so be sure to do this outdoors...

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[gus]

I also have a large steel boat and have found that Aluminium anodes from Jotun to be entirely suitable. The bonus is that they are a fraction of the price of Zinc anodes.

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[Piers]

Aluminium is used in brackish water, neither salt nor fresh - is this where you operate the boat?

<hr width=100% size=1>Piers du Pré
http://www.dupre.co.uk

 

[gus]

Boat has been used on the Clyde and west coast of Scotland for the past 9 years. I have no corrosion problems and the bonded anodes last about 4-5 years before they have lost about 50%.

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[alan]

I managed to do it with a camping gaz stove and a gas blow torch from above; the stove would not get the zinc hot enough on its own. I did it on the patio (whilst the wife was out !!!!) and make sure you use goggles gloves and strong shoes. Also if the zinc is 'dirty' you will need to ladle this off the top of the molten liquid before pouring into the mould. I used a plaster cast for the mold and lined it with talcum powder. I was copying a method described in PBO about 12 - 18 months ago (as someone else has mentioned) although in the article oiled sand was used for the mold - I tried this but the oil tends to burn and make a nasty smell. It worked O.K. with the plaster cast but you need to get a lot of heat onto the zinc to get it really fluid.

Alan
Nettuno, Italy.

<hr width=100% size=1>Alan Cloke