Centerboard questions

[Tipster1]

My boat has a 2-1 uphaul cable to block arrangement attached to a continuous line line exiting through the bottom of cuddy bulkhead that returns back through bulkhead to uphaul opening higher on front of trunk.

Is it characteristic for DSII CB to raise spontaneously while sailing? We were sailing in 8-10 knot breeze and it would pop up slightly from time to time, even when I believed (but can't prove it) I was is deep water. We marked the down line when fully lowered specifically to keep an eye on it and it would retract through bulkhead into cuddy anywhere from 2 to 6". Does cb need to be cleated in down position to keep it down while sailing in 8-10knots of wind? This is something I'd hesitate to do in variable depth New Jersey bays. If CB moved freely, I might bungee it leading to next issue.

We noticed that CB lowering difficult. Raising is very easy even considering 2:1 mechanical advantage. Shouldn't the board drop with minimal effort?

We tried raising and lowering maintaining some tension to prevent tangling, but lowering seems to be a problem. One time I had to pull straight up inside the cuddy to get it down and I was pulling a lot harder than I really wanted to. Is there any easy way to examine and deal with this without careening the boat somewhere?

[jeadstx]

You have the standard DS2 centerboard control line arrangement. The DS2 centerboard uphaul/downhaul (UH/DH) can be a problem and at times can jam. I have more prblems getting the board down that pulling the board up. When it isn't cleated, it can come up a little on it's own. Also water will get into the cuddy cabin from the front of the trunk where the UH cable goes thru. If you can get under the boat on the trailer you can look at it without careening it, otherwise careening is the way to go.

Do you have a centerboard bolt or the plates holding the centerboard in place?

John

[Tipster1]

Thank you for reply John. I'll get under boat in next few days to look around.
In Roger Conrad's book the diagram on p75 shows that the insertion of down line is much closer to pivot point than up line. This would seem to give very limited mechanical advantage. However there is a 2:1 pulley system that I do not have. Was that pulley arrangement standard or a modification? Can insertion point on CB tolerate that amount of tension?
I'm afraid I don't understand question regarding bolt or plates.

[jeadstx]

You might want to check out this discussion of the DS2 centerboard. viewtopic.php?f=2&t=4378

The difference between the bolt or plates is the early DS2's used a bolt as a pivot point for the centerboard. The later DS2's used plates with pins as a pivot point for the centerboard. If you have a bolt you can see it thru the inspection ports in the cockpit, if you have the plates you should be able to see them on the underside of the boat. The plates are probably easier to remove the centerboard if needed. My boat has the bolt. Both Tim Webb and I have "mystery goop" on our centerboard bolts which make removal of the bolt difficult.

John

[jdoorly]

My CB jammed in the down position a couple days ago, a problem I had thought I had fixed several times now! Of course my hopes (that the CB would un-jam or at least get back in the trunk somewhere in the process of encountering less and less water as I approached the ramp) were soon dashed and the following process was more reminiscent of scenes from "The African Queen" with colder water and less leeches. Now, here's the rub, somebody let 18" of water out of the lake that day leaving the ramp, and my trailer, at such an impossible sideways angle I couldn't get the keel to catch a trailer roller and the boat kept falling off to the side. I was having a day!

So, now what? What haven't I tried yet to stop the dreaded jamming CB? Hmmmmmmm. The "Hmmmmming" went deep into the night. And then it hit me, try a BIG FAT rope on the uphaul. One that can't slide to the side of the CB. The largest rope size I have on hand is 7/16" so I did some calculations and found that it could work. I drilled out the up-haul hole in the trunk to 31/64" and upgraded its sheave, and enlarged the anchoring hole in the CB to take a single overhand knot in 7/16 line. I'm leaving the 1/8" dyneema down-haul as is, as well as the 3::1 tackle on the down-haul and the 5::1 tackle on the up-haul.

So now we wait and see...

[Tipster1]

I feel your pain and understand your insomnia, Jdoor. I am waiting for rain to stop to get under my boat. One thing I wondered is your ratios of uphaul and downhaul. 3:1 and 5:1 is a whole lot more than diagrams I have seen and what I have on my uphaul. Pulleys on both up and down haul are really only 2:1 advantages. Turning blocks which change direction of pull, such as block at mast step, don't count. Actually they just add friction, though trivial amounts.

[Breakin Wind]

Somebody within the last week (2 at the outside) made a comment in another thread about clipping off the top of the CB housing to find/fix whatever their centerboard problem was, and then replacing & sealing the top of the CB housing again with a teak board. I can't find the posting now, but why isn't that a good idea, or maybe it is a good idea?

Taking it (of course) one step further, why couldn't such a teak (or other acceptable replacement top material) be made to hinge, seal and latch, with the obvious future benefit of being able to open it on demand to resolve whatever immediate centerboard issue one is facing? Its above the waterline so it would only need to seal against splashing water actions, not "airtight".

Thanks - Scott

[jdoorly]

Hi Tip, there is precious little on my DS2 that remains standard, that is if anything on a DS2 can be considered standard.

Hi Scott, a flip top CB trunk sounds great to me too, but the loss of the strong "box section" design would introduce flex probably just where you don't want it. Maybe if you kept all the 3-way corners intact and just made a small cut-out in the middle, you know- under the standard cleat table...

[jeadstx]

I have thought about putting a 1/2" to 1" hole in the CB trunk just aft of the mid-section to be able to use a rod to push the CB down if jammed in the up position. Any time my board has jammed, it has been in the up position. I've never had a problem with the uphaul. Just something I was thinking about.

John

[Alan]

John,

I was thinking the same thing, with a 1/2-inch pipe nipple between the cockpit and hull moldings so water doesn't get into the bilge. It seems to make a lot of sense, and I can't think of any reason not to do it.

[Tipster1]

To Alan and John.

Regarding installing a CB poker hole:

Before I got the DS II I had a 1977 Sunbird (SB) that had a factory designed 3/4 - 1" hole in top of CB trunk toward the aft end specifically to help lower CB. My boat was supplied with a length of steel conduit that PO told me might (heh heh) be needed to get CB to drop. On first launch CD wouldn't drop at all. We inserted conduit in hole in trunk and beat the hell out of it, to the point that the conduit was so flared out it was stuck in boat for a while. The CB dropped a little. We careened boat on nearby beach, beat the CB back into the boat. We repeated this cycle numerous times over an hour or so until CB finally loosened enough to come down all the way. Bystanders were amused/startled/appalled. In the SB, the CB hooks over a pivot so it can be removed easily from bottom of boat. Once out, back in yard, boat was careened again, and CB was sanded down enough to swing easily. Although, in many ways a more modern rig than a DS, the fatal flaw was a CB filled with iron filings that would swell up once water got in causing all sorts of problems. Once I got CB sanded down to it moved easily, pipe was replaced with piece of PVC that served same purpose. Fortunately, I did not have to rebuild CB, since sanding just removed a mm of Gel coat. Other SB owners had to fillet open their CB, remove the junk and rebuild them.
The top of inside of CB trunk was in direct contact with cockpit liner. You can actually see touch the aft edge of the CB when it is retracted as it was no more than 1/2" away. When sailing at some speed, a fountain often spouted through top of CB trunk into cockpit. First time this happened was quite startling, especially for first mate, who got first dousing from sailing geyser. Subsequently we learned to plug hole with piece of foam. SB also has a nice simple line running from aft edge of CB through top of trunk to raise the board. No fancy pulleys.

I hasten to add that the DS is a far better sailing boat. More stable, faster, and a lot more roomier than the extra 9" in length would suggest.

Having confirmed that my difficult CB raising is caused mostly by the early design of my DSII with no mechanical advantage and maybe some dirt, I am considering installing a 2:1 block between down haul and cuddy roof as has been described and pictured in many posts regarding later DSIIs. But the poker hole solution is also attractive.

Question 1:

Given all possible options, what is the best way to attach a block to ceiling of cuddy? I noticed a transverse cross brace nearby, but I don't know if it solid so that I can attach with ss wood screws, or hollow, in which case I might drill through and place some sort of anchor. Or do I go straight up through cuddy top and just use nuts and bolts to attach a strap? All the photos I have found do not show this detail.

Question 2: If you go the poker hole route, how big is the gap between top of CB trunk inside the cockpit and a the top of the trunk as it comes up from bottom of hull? And how much room is there at the top of the trunk when the board is all the way up for trailering?

Sorry this got so long,

Mark

[Alan]

Mark,

My upper block is attached just inside the cuddy opening, but I'm away from the boat and can't give you specifics yet. I THINK the block is attached by two screws going through the top of the cuddy, right at the edge where it's stiffened by the shape of the fiberglass.

The "fountain of water" problem could be solved by screwing a pipe cap onto the nipple.

I'd wondered about an uphaul cable attached to the aft edge of the centerboard. How did yours pass through the trunk? Was there a hole with a bushing in it?

The hole idea sounds better and better. No time to try it before the next time I sail, but it's a likely winter project at this point.

[Tipster1]

For the CB uphaul on the Sunbird there was a small rectangular slot in top of trunk into which was set a Harken Thru-deck Bullet block http://www.harken.com/productdetail.aspx?id=5041&taxid=1328 leading aft to a small clam cleat mounted on top of trunk

Please remember, as mentioned before, the top of inside of trunk was contiguous with inside of cockpit so there was no leakage into bilge risk and there was room at top of trunk for this block in this location in the Sunbird. lower part of SB CB was tight up against trunk when retracted. Anatomy and clearances inside DS trunk is unknown. Pipe nipple and cap would work, but wouldn't want to risk sitting on it. That's why we wound up with a foam plug.

[Tipster1]

John and Tim,
I looked through inspection ports and saw bolt head on starboard side and large nut on bolt on port.
Starboard:

Port:


It looks like this is the older system, and this board would be difficult to remove, if the need ever arose. Correct

[TIM WEBB]

Ah, lucky you: no goop!

The plates/wedges might be a little easier - don't know as I have no experience with them - but with either system, it's the getting the board back in that seems to give folks the most headaches ...

Oh, and I posted a couple more pix in my gallery of the CB DH arrangement: