Centreboard Removal

[Peter T]

Yes Andrew, exactly.
Thanks.
Regards Peter T

[Peter T]

Well, the new centreboard is going quite well, I purchased a 920mm length of 300mm x 10mm thick flat bar for $40.00 and traced out the shape and made the new board. No welding on this, it is all cut out of the one piece of steel.

took it off to the galvanisers and had it done at a cost of $66.00. Not bad I thought, a complete new centreboard finished for $106 and only took them a few days to complete. Excellent service.

Decided to prevent corrosion between the stainless "D "shackle for lifting the board by inserting a lubricant impregnated nylon bush as seen below

Turned up a new lubricant impregnated pivot bush and cut out the large nylon bushes to go each side of the board and fitted them to the bush as per below. The pivot bush is long enough to securely hold the large washers each side of the centreboard in place while the board is fitted back into its home within the centreboard case. Also, because I used 10mm plate instead of 12mm, I am able to fit two x 3mm large thrust washers each side of the centreboard. Had I used 12mm, with the thickness of the galvanising, it would have been quite difficult to get the exact thickness of those thrust washers. I will do away with the stainless steel wire strop for lifting the board and will use Dyneema cord all the way and terminate it around a thimble and held with the "D "shackle. ( Thanks again David for that idea mate.) Absolutely no chance of any corrosion with the centreboard as the only stainless is fully insulated from the zinc. Also, at the top end of the Dyneema, there will be a stopper to prevent the over lowering of the board leaving no chance for it to crash into the front of the case again.

Because of the repair that had to be done to the front edge of the centreboard case, I cut some off the leading edge of the board to allow for the thickness of the fibreglass repair that was done. After finally repairing the pivot holes in the actual centreboard case, I will make up a dummy top end of the centreboard out of craft wood, exactly the same shape as the new board and hang it in place. this way, I will be able to have the dummy board hanging vertical the same as where the new board will hang when the boat is in the water except it will be short enough to do so. I cant do it with the actual board as the boat is not high enough in the lifting frame, hence the dummy board will guide me. Then I will be able to produce a pad of that green nylon shaped to fit tightly to the front of the centreboard case and even grind a groove into it so the board will be held in place when its lowered and be cushioned at the same time and so not be able to damage the centreboard case again. I was going to use stainless steel for this, but thanks David for your suggestion of the nylon, excellent idea. It will be glued in there with Sikaflex into position and will be tight enough to hold there on its own as well as being very well sealed against the repair, and nylon does not rust, EVER, Ha Ha

[Kieran1234]

What does everyone thing of removing the centreboard completely and fibreglassing over the hole. I wouldn’t mind doing a bit of keel repair and was thinking it would be easier to just fully go over it

[Peter T]

I personally do not like that idea as your performance to windward would be quite badly compromised I would think. I believe that there were some boats built without centreboards, perhaps more so in WA. But personally I would prefer to work on mine, fix any issues that may have become apparent over the years and stick to original in this respect.

[Andrew]

My centerboard was rusted into the case when i went on the first sail. The performance upwind was terrible, made allot of leeway (sideslip), pointed poorly and the helm was unbalanced.

After restoring the centerboard, the difference was huge. she went up wind well with a lighter helm and pointed higher into the wind. On other points of sail (reaching and broadreaching) the plate can be lowered a little and adjusted to balance the helm too. A little plate lowered when off the wind brings the center of lateral resistance aft and help the boat track better in waves. Balancing the helm means less work on the helmsman or autopilot. (eg Autohelm ST1000 - the electricity consumption would be far less and the unit probably would last longer by not straining it) also less wear and tear on the rudder fittings.

The third point is when in unknown shallow esturine waters, the plate can be lowered and acts as an early warning system for avoiding grounding. A keel-base saver (see Peters posts on thin fiberglass keel bases)

The centerplate is a crucial component for good performance. I would hesitate to sail without one.. Kieran, I'd suggest under no circumstances permanently seal the centercase hole up, it would reduce the resale value (or make an unsuspecting buyer pissed off later) A tempoary hardwood plug silconed in, for easy removal in future, would be better if these performance issues aren't important to you.

If the plates still functioning, definitely keep it there. If my keel-base ever needs fiberglass repairs, i'd just glass up extra layers around the centercase slot (may not go to the extra length of bogging up the internal lip notch tho, it may be there for a reason like preventing pebbles from jamming the plate in)

[Peter T]

Excellent advice Andrew

[Ozzie]

Kierin, I would think that if performance is not an issue for you you could simply remove the board as you say but I agree that a removable wooden plug would be a good idea. That way you can leave the opportunity for a subsequent owner to reinstate it.

As said, WA boats have no cb and reduced rig. I always assumed this reduced rig was because of the lack of enclosed waters to use there. Most WA owners are forced to use open sea. You can compensate for weather helm with sail trim. If you do a search for trim on here you’ll find reference.

People sail for different reasons. I would not be interested in racing but I’m sure many get much pleasure on squeezing the last knot out of the boat and good on them. I’ve used my boat without the cb when it’s been stuck at the end of the season it didn’t reduce the pleasures I got from the boat at all, just took longer to get home, and is that a bad thing? My $0.02 worth.

[Ozzie]

As an afterthought maybe you could get some lead ingots of suitable size cast and fix them in your wooden plug. Extra ballast in the bottom of the keel would compensate for the standard rig. Just a thought.

[Kieran1234]

Thanks for the info I’d say I won’t be covering it up. I just wondering as I thought it could of made fixing the keel a bit cheaper and quicker but if it’ll sacrifice performance I won’t be covering it up.
I think in the next few weeks I’ll be setting up something to get the boat off the trailer and up high enough to do repairs. Where would the best spot be for the straps holding the boat up to be. Or can they sit anywhere

[Peter T]

Have a read through my post called
"Lifting Frame" under Technical information and you will see all you need to know. My lifting straps are in line with the posts of the lifting frame so just look at where the posts line up on the boat on a side on photo. What you will find is just a bit forward of the centreboard case and just behind it. Because of the profile shape of the front of the keel, there is a slight tendency for the straps to want to spread apart. Thats why I used a ratchet strap between the lifting straps to stop them spreading apart.
I just went and measured it for you. The lifting frame has its posts 1680 centre to centre front to back. The centre of the back lifting strap is 100 mm rear of the centreboard opening. The centre of the front lifting strap is around 600 mm in front of the front of the centreboard case opening. The front posts of the lifting frame is just about exactly in line with the front two staunchans. At the moment, I only have the rear lifting strap in place and replaced the front strap by using a screw type jack stand with a block of 90 x 90 treated pine on it which I placed just far enough to the rear of the front strap so I could remove that strap to be able to work on the bottom of the keel where the strap was located.
I still have to do the same to the back strap once the front one is back in place.
Let me know if I can help you with any other info