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View Full Version : The tired old stem scarph....



ACB
08-12-2001, 04:18 AM
It's a bit slack. Can, in fact, see daylight through the outside bit, now that the paint's off. When the paint was on, the paint had developed that "interesting rippled effect", typical of a slack joint, drawing the surveyor's eye to it.

Can't blame it, really. The copper clenches holding it together have been fighting the pull of the bobstay for 56 years now (that's 64 years, less five for lay up during the Second World War, and three years for other times we have not fitted out, mainly due to refits!)

Simple solution - tighten the clenches.

Snazzy solution - make an internal shaped backing plate and an external plate with the bobstay eye in it, and through bolt the lot. One might put a second eye in for riding to a short nylon snubbing rode at anchor as per picture in "The Ocean Sailing Yacht".

So, folks -

Q1 - is this worth while doing?

Q2 - what material to use?

Lower bobstay is chain, keel is cast iron, floors are wrought iron, stem band is galvanised iron, so mild steel, galvanised, looks like first choice but that would involve iron bolt through oak stem, which I am un-keen on having just "done" all the iron floor to frame bolts, which had not enjoyed their contact with the oak grown frames and, in a couple of places, had triggered rot.

A bronze fabrication seems better perhaps in conjunction with a bronze stem band, on the grounds that a bit of "more noble" is OK, it's the bit of "less noble" that gets it, and 3 tons of cast iron is not going anywhere fast, but would I get huge galvanic action and alkali build up round the fastenings? I guess not if the copper planking nails and bronze hood end screws are OK.

Thanks for your thoughts....

Thad
08-12-2001, 06:55 AM
Thanks for your thoughts, thinking it through so well. My question is whether the scarf is really open. Is this a result of drying out? Is the opening between the shoulders at the end of the scarf? Was water coming in through the joint? Is there sign of weakness in the wood around the present fastenings? The AC Jubilee is at hand. Are you going to be over in time to race round the auld mug?

Dale Harvey
08-12-2001, 08:37 AM
Genuine wrought iron, smith forged in a coal forge, double dip hot galvanized. Seal the bolt threads with zinc/epoxy. If the galvanizing is properly done and the chain leads to a replaceable pin that bears the chafe load, it should well outlast the rest of the boat, not to mention your mortal shroud.

ishmael
08-12-2001, 09:13 AM
ACB,

Whatever you decide, why not take an afternoon and tighten the clenches? Aw, now what fun is that? Then you could just forget about it for another half a century(laugh).

I think you have thought it through quite well...so have after it.

Mirelle
09-11-2001, 06:14 PM
Thanks, everybody. We are going for the bronze plate and bronze bolts solution (my brain finally engaged and remembered that they were copper clench bolts so adding bronze would be no problem.

Yes, we tighten the old bolts of course.

The computer changed my name for me because it lost the old one when I changed my internet address, so I'm now named after the boat!