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Re: Centreboard Removal

Posted: Wed Nov 15, 2023 6:04 pm
by Peter T
Hi ian, have a look at these mate.
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shows how flogged out my holes in the centreboard case was. you can see here the recess in the fibreglass where originally there was a rubber seal fitted in there to try and seal around the bolt. they were fitted from inside of the cavity of the centreboard case and I have no idea how on earth you would ever get them to stay in place to be able to assemble the pivot bolt. As I had to re fibreglass the holes, I made up a plug of the green nylon ( which has a lubricant impregnated in it) to jamb up inside the case and fitted a dummy green nylon bolt prior to glassing it up. I used epoxy and woven rovings, super strong to glass it up on on the worst side and was then able to remove the dummy bolt and then put it in from the repaired side to be able to fix the other side the same way. I now dont use a seal on the pivot bolt but I dont need to as I have fitted a cap and then glassed over that to seal it all up as shown in previous post on here
Pivot Bolt and bushes.JPG
this is the new pivot bolt not yet cut to length and the washers and bush made of the same nylon
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This is the block and dummy bolt I used. note the two lengths of metal to enable insertion and removal of the block. The reason I used the green nylon is that epoxy does not stick to it due to the lubricant qualities if the nylon
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Above is the set up prior to glassing it up with epoxy and woven Rovings

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This shows it glassed up
and Below shows the tapered blocks as well as a bump block I fitted which does two things. 1 stops the centreboard from flogging side to side when board is down and 2. the bump block prevents damage to the end of the centreboard slot at the front when lowering the boar in case someone lets it drop and then it would slam into the front of the case and break through the fibreglass. which was the case with minr so I had to glass the front edge inside the case and that is why I fitted the block. It is also why I cut out a bit of the leading edge of the new centreboard. see second photo below the top front third of the leading edge. this cut out gave me clearance for the repair of the centreboard case
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Below shows cap fitted over bolt head and nut by using sikaflex. I then glassed over the cap to fully seal it. if removal is required in the future, the cap can be chisseled off again as its only a single layer of glass
20210515_153733.jpg


Hope this is clear for you and hope it helps. Cheers

Re: Centreboard Removal

Posted: Wed Nov 15, 2023 9:32 pm
by Andrew
Thay sounds right Ian, my one still had ok fibreglass walls to bear on. (and no flogged out hole either)

Also the fact i took everything to a precision engineer - (galv centerboard and my new pivot bolt. Plus the old bush/washers.) they selected the plastic and figured out fine tolerances/dimensions needed and made it all fit. Its stuff well beyond me, so left it upto them.

They made the new central bush a tight fit in the galv centerplates pivot hole, no slopping about. Also a snug fit for the pivot bolt and outer plastic washers (probably prevents leaking here, its like a propellor stern gland, tighten nut makes outer washers expand onto the shaft)

The big side packers of black HDPE made the centreplate snug and also help prevent the fibreglass centercase walls from crushing inwards, once the pivot bolt is tightened up. Also i never overtightened it, this could cause case damage or bindup the pivot.

Never wanted to glass over it again, only silicone, for easy future maintenance access.

Re: Centreboard Removal

Posted: Fri Nov 17, 2023 9:41 am
by IanS
Many thanks to both Peter and Andrew for taking the time to respond with more details.

It looks like Andrew's nylon washer is half buried in the fibreglass and Peter's nylon washer is sitting on top of the fibreglass. I hope to find time this weekend to clean up around the bolt and figure out what to do.

Peter's dummy bolt in place while glassing up the hole was a stroke of genius as it's pretty inaccessible down there.

Wish me luck, I'll report back.

Re: Centreboard Removal

Posted: Fri Nov 17, 2023 8:00 pm
by Peter T
Hi Ian. Don’t hesitate to get in touch if you need to mate. Good luck with it . If you send me a PM, I will send you my phone number. Cheers

Re: Centreboard Removal

Posted: Thu Oct 31, 2024 11:52 pm
by Kelpie
Just like to thank everyone on this site for their information on making new keels as I have just purchased a 563 recently that came without a keel in some of the photos it appears there is a slight kick in on them is this important got lots of other jobs to do on the boat still but will need to get it moving on getting it done soon as I'm keen to get her out sailing as possible I've owned several other yatch in my life and sailed the Queensland coast many times but the time has come to down size ps the boat number on this old girl is #16

Re: Centreboard Removal

Posted: Fri Nov 01, 2024 10:58 am
by IanS
Good luck with the keel.

There's a nice drawing here you can send to the fabricator: viewtopic.php?p=648#p648

Peter's is a bit different on the leading edge by the looks of it.

Cheers, Ian

Re: Centreboard Removal

Posted: Fri Nov 01, 2024 4:15 pm
by Peter T
Hi Ian. Just to explain the different leading edge on my centreboard. In the past, someone had let the centreboard drop fully down without controlling its weight on the lift rope. This then let the board smash into the front edge ofvthe centreboard case causing damage. I had to do a fibreglass repair to that area and then, to prevent the same thing from happening again in the future, I installed a specially shaped block of nylon as a bump stop to the front of the centreboard case. Then, when I built my new centreboard, I made allowance for the stopper block by cutting away some of the leading edge of the centreboard.
I hope this explains it for you. You can see on the right hand side in the photo below at the top where I cut its width down for the reason explained. If you look in my post two or three post previous to this one, you will see the photo of the bump stop and guids I fitted to the centreboard case.
20210202_141258.jpg
Happy sailing

Re: Centreboard Removal

Posted: Sun Nov 03, 2024 4:25 pm
by IanS
Ah yes, I see. Every detail was thought through. Nice one Peter.
Ian