International Moth 3848 mast step puzzle

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Pike
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International Moth 3848 mast step puzzle

Post by Pike » Sun Dec 02, 2012 9:46 pm

I've just got hold of International Moth 3848 (thanks to JB9 on here :) ) which is a Sean Cox Dragon, I'm a bit puzzled regarding where the mast passes through the deck as the forward compartment is open. Is there meant to be seal/boot of some sort around the mast at deck level? Hopefully the photos will help identify the issue.

I did have the thought of modifying the mast step so that it was similar to a Laser with a tube that was sealed from the compartment or alternatively changing it to a deck stepped mast.

Any advice will be gratefully received.
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jpa_wfsc
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Re: International Moth 3848 mast step puzzle

Post by jpa_wfsc » Sun Dec 02, 2012 10:01 pm

Photos?

It sounds like the way the OK worked... with a rotating mast and no stays? So you cant easily convert to deck stepped.

The theory is that the small compartment the mast rotates in will not flood when you capsize as the mast foot will stay above water level. This is often the case, but you do get a puddle in that small space which is sealed - the only way to empty this is to bail it out with a sponge. I have never seen a gaiter or similar on these.

Usually either the foot, or the deck hole, will be adjustable for/aft so you can tune the mast rake.
j./

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British Moth, 630, early 60's 'Pisces'

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Pike
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Re: International Moth 3848 mast step puzzle

Post by Pike » Sun Dec 02, 2012 10:15 pm

Can you not see the 2 photos in the post?

It is a rotating mast but also has stays. The mast does not go into a tube but is open to the whole forward compartment which has bulkheads in it but they have lightening holes in them so potentially it could take on an awful lot of water as it is at present.

alan williams
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Re: International Moth 3848 mast step puzzle

Post by alan williams » Mon Dec 03, 2012 9:55 am

Hi Sean was an old friend of mine and tended to think out of the box. The holes in the bulkheads were most likely to have been covered with "fablon", He also used to use it instead of hatch covers. Sean also was the first moth designer to produce the one of the first British at the time impossible to sail (unless you were Sean), ultra thin skiff moths called the Demon. The first narrow moths were developed in Switzerland for sailing on the lakes.
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JimC
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Re: International Moth 3848 mast step puzzle

Post by JimC » Mon Dec 03, 2012 10:35 am

Sticky back plastic was quite common back in the day for such purposes. Never really appealed to me. Of course its one thing getting a seal on new perfectly flat bulkheads, and quite another getting a seal on bulkheads covered with years of dreck...

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JB9
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Re: International Moth 3848 mast step puzzle

Post by JB9 » Mon Dec 03, 2012 12:33 pm

There was an old mast boot/seal which looked as though it should stop any water but never did.
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PaulM
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Re: International Moth 3848 mast step puzzle

Post by PaulM » Mon Dec 03, 2012 3:09 pm

As I remember, on the last of his Demon Kings and his first Dragon he used a neoprene 'boot' glued to the deck and then tied round the mast once it was stepped.

Paul

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jpa_wfsc
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Re: International Moth 3848 mast step puzzle

Post by jpa_wfsc » Mon Dec 03, 2012 4:29 pm

Pike wrote:Can you not see the 2 photos in the post?

It is a rotating mast but also has stays. The mast does not go into a tube but is open to the whole forward compartment which has bulkheads in it but they have lightening holes in them so potentially it could take on an awful lot of water as it is at present.
I can see the photos now - could not earlier - odd!

I also now see the problem - quite a substantial problem! I think the neoprene boot is rather a must there!
j./

National 12 "Spider" 2523
Finn K468 'Captain Scarlet'

British Moth, 630, early 60's 'Pisces'

!!!! Not CVRDA !!!!
Comet Trio - something always ready to sail.

Pat
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Re: International Moth 3848 mast step puzzle

Post by Pat » Wed Dec 05, 2012 7:23 am

The photo change may be due to the forum migration to a server with newer software.
(Half Cut and What a Lark Removals Ltd)

Pike
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Re: International Moth 3848 mast step puzzle

Post by Pike » Fri Dec 21, 2012 11:37 pm

I've just found some pictures on the Moth Archive of a Dragon 2, I noticed that the design was changed to a deck stepped mast. I've removed the deck now as most of the plywood bulkheads were rotten or loose so will look into modifying the structure to support a deck stepped mast and hence creating a sealed buoyancy compartment.

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Re: International Moth 3848 mast step puzzle

Post by JimC » Sat Dec 22, 2012 6:46 pm

Pike wrote: I've removed the deck now as most of the plywood bulkheads were rotten or loose so will look into modifying the structure to support a deck stepped mast and hence creating a sealed buoyancy compartment.
Seems reasonable. Make sure that the inwards compression loads from the shrouds are dealt with as well as the straight downward load from the mast, and also think about what's happening with torsional load from the wings.

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