When I built Scratch I swithered between building the daggerboard, as per the original design, or the centreboard for which John had prepared an additional sheet of plans. In the end I went for the daggerboard on the grounds it would be easier to build and if others were happy with it, why shouldn’t I be?
I had two bad experiences with the daggerboard, once hitting a rock at North Berwick, and then hitting the only shallow gravel bank in Loch Ness. In the first incident the daggerboard jammed, and I could only free it by using the oar as a hammer – all the while drifting towards more rocks. In Loch Ness the glass on the board splintered and I cut myself quite badly. Both incidents were the result of my carelessness, and I will try to avoid doing the same again. I’ve also found the daggerboard to be difficult to raise and lower while sailing singlehanded, which makes sailing on and off the beach a bit tricky.
Last summer I decided the daggerboard had to go. I had to adapt the centreboard plans slightly for this retrofit, but is was mainly plain sailing – though of course it took longer than anticipated!
Here are a few photos of the project. It was a little while ago now and I’m a bit hazy about some of the details of what I did!
Here’s the original daggerboard case. I’ve cut out the extension to the seat front that ran along the inner edge of the case (which the rowing thwart rested on). I’m making cuts into the rest of the seat front prior to cutting it off. I’ve already made the new board, but the only photo of that I can find is this one of the newly poured lead:
Judging by the date on the photo, I made the board over the winter – I’d forgotten that!
The adjustable ‘comb’ for the stretcher (footrest for rowing) has now been removed, and the slot cut in the floor.
My (then new) Japanese saw has cut the top of the daggerboard case off nice and cleanly.
Trying the centreboard case for fit. A great deal of the project involved ‘offering’ parts up and making adjustments.
Case log and horizontal for rowing thwart now fitted. Still all a dry fit.
You can see on the right that I made a mistake cutting the slot in the floor – I forgot to take account of the fact that the actual case isn’t as long as the outside wall of the case.
Gluing in progress. Clamps and screws.
And the other side glued. It took a while to work out a sequence that allowed me to glue the case securely while only being able to work from one side. If one were doing this when originally building the boat, neither the seat nor the planks would be in place yet.
Trying to work out how to rig the uphaul. The plans show a block well forward of the case, coming back to cleat near the front of the case. I wanted an alternative, as that set up (a) prevented someone sitting forward of the case, and (b) meant leaning right forward from the helm to work the cleat.
The long slot in the seat is the original daggerboard case. The hole to the left is just a gap in the ply sandwich that made up the daggerboard case. One end of the pivot pin lives in the long slot. I spent many hours fiddling with the washers, grease and nuts in that slot – and it was too small for my hand, so long nosed pliers, sticks with tape etc, etc. Luckily I could also access the gap from below as well, but still very fiddly.
At the top left of the case you can just see the aluminium plate that the up haul attaches to.
Same stage, but from the other side. You can see the head of the pivot pin. The pin is below the waterline, so careful fitting was essential.
These people were my saviours. The pivot pin is a stainless steel tube with chamfered ends; exactly the same width as the case – to the outside of the case. Trying to source this took ages. On the forums everyone says ‘go to a metal shop’, but there are very few small scale engineering business around here.
No tubes are available in the width required, and buying a short length – about 12cm – was tricky, most places wanted to sell metre lengths. Eventually I tracked down The Metal Centre which specialises in supplying small quantities. They also do some metal working – but unfortunately their lathe operator was on holiday. They sent me to George Brown & Sons est. 1828, where my wife’s uncle did his apprenticeship before ending up chief engineer on oil tankers. Very kindly someone turned my steel rod into a chamfered tube.
Fitting cleats for the stretchers. Note two ranks – one for for rowing solo and one for rowing tandem.
And the other side.
Fast forward. I took the opportunity to scrape back the floor, and to repaint the inside of the boat.
Boat standing on its side so I can cut of the bottom of the case – this was built over size to project below the slot. Fibreglass tape was used over the joins, and the old daggerboard slot blanked off.
The slot covered with gasket to reduce drag. No idea if it’s necessary – opinion differed!
The centreboard performs wonderfully – so exciting being able to adjust the depth with a pull on the line, and being able to sail on and off the beach without a hitch.
I don’t seem to have taken my camera with me sailing since fitting the new board. When I do, I’ll provide an action shot.