Center Board


Taming Restless Nights

Sleeping well on a 26X highlights a problematic issue, rock n roll nights! Unless in the most sheltered of marinas, more than a ripple can have the boat swinging wildly from side to side. Coupled with its dancing tendency on anchor, the options are not too bright. Put the centerboard down to stabilise the boat and you get the board clunking in its' trunk like some orc drum beat from the depths of Moria. Leave it up and better strap yourself in!

This issue has been teasing me insanely ever since our first 'up till 4' morning. The thing is, a grp mould needs a certain angle (at least 4degrees) in order to seperate, hence the trunk is wedge shaped. This, with a sloppy hinge pin works well when sailing as the water pressure simply wedges it into position. Making a perfect bush bearing on the pin without support elsewhere would put far too much strain on the metal ware. The board stress is against the top and bottom of the trunk.

A solution appeared in my head quite randomly whilst looking at the cb and hanger components. A piece of 1/8 316 plate between the cb and the hanger could just fit in nicely.... that sorts out the slop at the head of the board. All that was needed then would be some sort of clamping arrangement for the lower part that could be deployed when peace was required. A brazen idea formed...

A visit to the scrapyard and I came home with a handful of taps and valves... perfect! I modified a body and silver soldered (brazed) it to a plate, and went about fitting it. It would be 2500 miles later in the Aegean before I could test it so the theory had to be good, and if not I would need to be able to remove it possibly with scuba gear. (ref pic below.. the red line is where I ended up cutting the final shape, yellow dot where the tap compresses. I love the fact that this piece slots into the top 'stop' bar and is held in with the same pin that holds the board in. A nice loose fit untill it gets clamped)


When this is fitted, I had the plate on the starboard side as that is where there is access to the trunk.




Bracing the board hanger point. A similar piece is on the other side, and the hanger is actually on the 6mm button head bolt on the lower right. I changed the wire for one with a swedged eye on the end... much better than the telurite mess. It also means it will pull up into the trunk through the hole in the fiberglass, which gives me an extra 4 or so inches of extra leverage when hauling the board up. In theory this can make a big difference, especially as I get ready to arm the board with lead!

The tap head on its 6mm plate. The whole assembly can be easily replaced and renewed if ever neccessary.




  Weighting the board      
  The other issue I fancied having a go at was adding some weight to the board. It is a long board, and by my reckoning a little weight would go a long way, the flipside being pulling the thing up without ripping the pin out!


These lead slugs were cast in some fine sand from some scrap roofing sheet and old windows. A hole slightly larger in the board allowed me to just pop them in. I then made a larger hole further up to get more in.. about 20kg for now. I've also just learned how to DIY pellets. An old navy diver sold me a load really cheap, explaining his bit of angle iron with a series of 1/8 holes drilled in the corner. This causes the lead to form small droplets as they run through. clamp this seiving arrangement a couple of feet above a bucket of water and fill your boots! As we like to scuba dive, the price of shot is around £7/Kg. So 2 weightbelts (15 +15) plus 30Kg for board = £420. Buy scrap @ £2/Kg yields a £300 saving! I will put in another 7Kg of this and then pour some resin in to stop it all flopping about. I put a cover plate on one of the holes, though I really don't think it too important. Eases the drag a bit.

A thing folk easly forget is the displacement of water. One could fill the board with resin, which would make it possibly heavier than this lead tippd one. However, if one then weighed the two boards under water, the leaded one would be 5% lighter, the solid board wold lose in the region of 90% (resin density is not far off water.. 1:1.2) Interestingly, concrete is about 2.2, so loses nearly half its weight whatever the size of the mooring block. Iron around 8 and lead sits at 11, whereas gold weighs in with a whopping 22!!!! Twice the weight for the same volume of lead.. mental!

I loathe the turning arrangement the cb wire goes through when coming through the top of the deck. With the extra weight and the massive leverage I decided to make some further mods. I hung a triple block on the mast and attached another to the cb wire. At this stage it does not work well. It does not need all that extra leverge to get the board up, in fact the blocks are a disaster, snarling up etc. At the moment if I need to move the board I do it at the mast. Bit of a pain, but no big deal for now.
  Sea Trials      

Anyway, I would like to report that the plan worked better than I could have expected. Though we didn't sail as much as I would have liked, we did plough through some fairly heavy seas. As to sleeping on the hook... it felt like a different boat. calm and quiet. I noticed too that in port next to 40' keel yachts that our mast was not flailing around any worse than the big boys. The board was a little more fussy to get up when underway as was to be expected, but such a small price to pay! This is one of my most satisfying mods, it really calms her down.. especially Mandy!!