Centreboard Removal

[Peter T]

Hi ian, have a look at these mate.

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

this is the new pivot bolt not yet cut to length and the washers and bush made of the same nylon

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

Above is the set up prior to glassing it up with epoxy and woven Rovings

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

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

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

[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.

[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.

[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