Wood for sacrificial shoes underwater.

[Mudisox]

I wish to shoe my keels with wood to provide a sacrificial strip for when I ground. I have access to free, and plentiful supplies of native UK wood- Which is best? Elm seems to ring a bell somewhere in my mind.

 

[sarabande]

Elm was used for harbour piles and water pipes as long ago as the Romans. It is very resistant to decay under water. But, given that the UK has lost nearly all the elm trees (bar Hove and Selsey, and few other isolated places) unless you have asecret supply, that wood may not be available.

Otherwise, green oak, which steams quite well to shape, and which is pretty abrasion resistant ?

 

[bobgosling]

Excuse me for pggy-backing on this thread but I have just replaced the runners under my rigid pram dinghy with Sapele ( a kind of alternative Oak according to the bloke in the woodyard ). It won't be subjected to quite the same duration of submerssion but I'm wondering now whether I have been sold a lemon and have the wrong type of wood ?

 

[srp]

Sapele an alternative oak? Never heard that before. Oak is more durable underwater, much tougher, a different colour, easier to work - in fact I can't think of many similarities between the two apart from the fact that they come from trees. I'm sure sapele will be fine on your pram dinghy, but it's amazing what people will say to persuade you to buy what they happen to have in stock. Robbins have an informative website, and they understand about marine timber - well worth a read.

 

[Norman_E]

I seem to remember sapele being called "[--word removed--] mahogany". It is much softer than oak, and softer than true mahogany.

(They "word removed" the word that refers to an illegitimate person)

 

[Gunfleet]

You can find elm, but you have to go to country woodyards - the sort who'll cut down and plank a tree for you. They've always got some.

 

[Birdseye]

Did both keels on my Prout with green oak, bonded on with west epoxy. They were still there when I sold the boat 7 years later and still sound as a bell.

 

[Robin2]

They are sacrificial - don't spend to much money on them !

 

[Bajansailor]

If you were doing this job in the Windies, you would probably be looking at using greenheart - a very durable, hard wearing, heavy timber - blunts drills quickly!
There are plentiful supplies here (obtained from Guyana) at a reasonable price - what is availability like in England?

 

[richardandtracy]

How much sacrifice of time are you prepared to put up with? A fairly dense pine coated with marine grade tanalising repair fluid will last a year/two or up until you use the shoe a few times - then it'll rot like there's no tomorrow. This may be OK if replacing the shoe costs little more than time. If you have to pay for a haul out, then stick to hardwood. The pine would have to be considerably thicker than its hardwood equivalent to absorb impacts.

Now, I know tanalising repair fluid is a 'Trade Only' material, but I got it by turning up while splattered in paint wearing old [read charity shop reject] clothes and a white van. To be honest, I've a threadbare jumper that's got me trade discounts worth hundreds of pounds..

Regards

Richard.