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Post by paultp on Aug 17, 2011 15:09:49 GMT
At the nationals I found that my hull (Skinner built 784) under the cockpit was still flexing and showing signs of cracking again.
I discussed the issue with a couple of people and my options seem to be a rehull (which I am not capable of doing) or strengthening the cockpit to stop it flexing.
The rest of the hull is sound but the middle part of the cockpit floor is definitely flexing which is probably the result of having first Roger Wollin and then me leaping about in it.
I aim to repair the underside over the next few weeks but does anyone have any suggestions as to what to do to strengthen and stiffen the cockpit floor?
Not too bothered about weight but don't want to add too much.
Cheers
Paul
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Post by Pie-eyed on Aug 17, 2011 16:20:59 GMT
I think you need to ask the man who is king of light and strong.... Mr John Claridge
He is a wealth of hands on knowledge having used all sorts of materials and i'm sure could advise.
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Post by pegasus on Aug 18, 2011 7:35:18 GMT
Paul
When I bought Bertie the floor certainly flexed. I used materials from Epoxy Resins to strengthen the hull (and fill the gaps!).
Email me your home address and I can send you a sample. But talk to me first before using it as I the instructions they gave were not very clear.
Simon
BM708
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gmc
Mothist
Posts: 77
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Post by gmc on Aug 18, 2011 9:16:14 GMT
seems to be a problem with that generation of Brian's boat; had to get Rupert Whelan to rebuild the cockpit floor ion 787 after the king-post tried to escape duuring the 2006 nationals; too. Might be worth Might be worth speaking to Gary as well
they won't take much rig tension
Mark
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Post by george on Aug 18, 2011 12:37:23 GMT
It is my experience as a former builder of wooden boats that plywood does deteriorate. It delaminates, warps, and rots!!
You are talking about boats which are 28 years old so you can expect problems all the time, nothing lasts forever, and a new floor is the only proper fix.
George.
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Post by paultp on Aug 18, 2011 17:40:08 GMT
I think I'm coming to the conclusion that a re-hull is the best option. Trouble is all the moth boat builders are down sarf whilst I'm oop north.
There is a local builder who builds Streakers, Solos and miracles so I might have a word with him.
My worry is that I'm just spending too much money on the boat and I would be better off just buying another. Losing 784 would break my heart though (awwww!)
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Post by paultp on Aug 21, 2011 23:03:55 GMT
It is my experience as a former builder of wooden boats that plywood does deteriorate. It delaminates, warps, and rots!! You are talking about boats which are 28 years old so you can expect problems all the time, nothing lasts forever, and a new floor is the only proper fix. George. Right George, money where your mouth is - stand by for some photos and a stupid plan. Grateful for your comments. <edit>Stupid plan on hold as local boat builder is going to look at 784 </edit> |
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Post by Fatboysfly on Aug 23, 2011 10:50:30 GMT
Advice on hull strengthening. Currently stripped 713 Meritlock decks off. Going to put in complete false floor using 5mm Elite and epoxy fillets around perimeter and drill through hull for epoxy rivets. Absolute nightmare getting the old part false floor and tape off, ha ho done now. Whilst my decks are off any advice on strengthening the mast strut area greatly received! bracing ? adding struts to along keel line ?
Any suggestions would be appreciated.
JH
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polyfiller
Mothist
14 x winner of the annoying git on the water award.
Posts: 126
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Post by polyfiller on Aug 23, 2011 12:24:08 GMT
From memory the meritlock only has a solid bit of wood bracing from the bottom of the front of the plate case to underneath the mast. I reckon a major improvement would be to make some triangulation frames up from ply to spread the load along the hog and a space frame / bulkhead out to the shroud plates. JC seemed to have come up with the lightest approach but am guessing Gordo could also advise.
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polyfiller
Mothist
14 x winner of the annoying git on the water award.
Posts: 126
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Post by polyfiller on Aug 23, 2011 12:25:13 GMT
I meant Goffo in the above ....poxy auto spell corrector !
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Post by paultp on Aug 23, 2011 12:58:59 GMT
Advice on hull strengthening. Currently stripped 713 Meritlock decks off. Going to put in complete false floor using 5mm Elite and epoxy fillets around perimeter and drill through hull for epoxy rivets. Absolute nightmare getting the old part false floor and tape off, ha ho done now. Whilst my decks are off any advice on strengthening the mast strut area greatly received! bracing ? adding struts to along keel line ? Any suggestions would be appreciated. JH I don't have a false floor in 784, it seems to be a single piece of 4mm ply each side. There are some horrid bits of cork glued to the inside of the cockpit which seem to have no structural use whatsoever but would be a pig to get off. I didn't want to take the decks off so my stupid plan was to drill guide holes round the edge of the inside of the cockpit then turn the boat over and cut out that part of ply on each side. I was going to then scarf the edges of what was left on the hull, plane off the ply left on the frame bits round the centreboard case and the hog (?) and then replace the ply using scarf joints and then filleting and taping inside the cockpit. I suppose some pics would be useful. I'm going to find out what the local boat builder will charge me to do it as he has the knowledge, facilities and materials which is more than I do. I've (hopefully) attached a pic of the mast strut in 784 (built by Brian Skinner), please excuse the leaves, they are the last remnants of a field mice nest from the late 90's! The pointy bit of the boat is behind the strut so it looks like the various frames of it go along the keel line and to the shroud plates as Toby suggests. Attachments:
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Post by godfrey on Aug 23, 2011 14:21:02 GMT
I dont always reply to these threads but I'm getting a rather bad feeling about this one, Paul.
I'd think carefully about the fairness of shape and integrity you are likely to achieve with this approach. Frame-less hulls from female jigs bring their own issues. Its a pity that you can't throw it on any empty trailer heading south and sail your Streaker for a month & I'd be happy to help you out!
It sounds like your best bet would be to clad the original floor with a new inner skin, retaining as much of the original as possible. Claridge & myself used to use 4mm & either staple or screw through/remove screws after. You must be certain not to leave any un-glued voids between, but you get a 9mm floor! We have 10mm in the Solo.
All this is similar to what Jeff is doing. Fillet the perimeter neatly and there is little evidence of the repairs to be seen.
Some Meritlocks had trouble in this area when the kit assembler failed to achieve a 100% bond and moisture got between, but if the problem was local, a patch would suffice. Give me a call if you like (phone No on website still unchanged)
G
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Post by godfrey on Aug 23, 2011 14:40:07 GMT
Talking about Jeff's Meritlock, most of those old king posts usually fell out by themselves! People heard somthing rattling about in the front tank and thought they'd left a paddle in there. It was actally the king post and tennon blocks that had fallen off when the cascamite glue failed.......
If the decks are off you're laughing. Build a strongback/web everywhere between the king plank and the keel seam. I use 9mm gaboon cos it won't bow out of column,- the front part can be cut away to save weight but its also a chance to replace the grp tape with a double epoxy fillet. Sorted....
Before you ask I'm currently out of 9mm but you could try scrounging off Jacko. Not easy, I know! The bugger made me pay for 10" of brass keelband for me Merlin! (and its one of his!)
PS Hamlet now floats, but we've got too much weed for the Merlins. Will send photo to Jacko.
G
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Post by Fatboysfly on Aug 23, 2011 15:58:58 GMT
Thanks for advice Goffo, yes Jacko still squeaks when he walks, charged me for a bit of sand paper once!. I was thinking of laminating 2 skins of 5mm Elite ( cos I 've got some sheets)? Would you leave the diagonal strut in place, all be it epoxied in, and what about bringing the loads together from the shrouds framing to the bottom of centre board case, or is that over the top. I think I can take some weight out as you say from the mass of ply at the front end, also reduce the size/corners of the shroud plate pieces, rear deck beam etc.
Good to hear from you, thanks again
JH
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Post by Fatboysfly on Aug 23, 2011 16:05:21 GMT
Nearly forgot, thanks for pic Paul, I think I will frame up like that. Regarding the floor I think double floor is the way to go. I had to use a router to shift the ply until I hit a previous bad repair that just fell off, cleaned it all up with sharp chisel, lots of sanding, now ready for double floor.
It's a lot of work though, serves me right for buying a cheap boat under the influence of to much speckled hen on ebay, oh well at least 713 will have new lease of life.
Thanks
JH
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