Aphers

Hi there, I sourced my epoxy and the tape from MB fibreglass who are based in NI. I used the 'Epolam' epoxy which was substantially cheaper than any other option I found. Their tape is 315gsm. When I ran out of that, the second roll I bought was from Fyne Boat Kits and that was only 200gsm. I'm not just how critical the weight is, I doubled up in a few places when I had to switch to the thinner tape. I would say there is a certain degree of wiggle room in exactly what materials you use, and the quantities you'll need. E.g. the bill of materials suggests considerably more epoxy than I have used, but only one roll of tape. I bought 4 lengths of 25x50mm ash and will have hardly any of that left over.

And that's me all ready to start painting tomorrow!

I'm thinking along similar lines. I intend to use eye-nuts rather than wing-nuts at the nesting bulkhead. I will also have pad-eyes on the floor near the aft seats, as lifting points. The distance between these points is about a metre. I'm trying to track down a suitable inflatable fender or buoyancy bag that can be strapped fore and aft, one on either side. This would give useful extra flotation nice and low in the boat, and reduce the amount of water shipped in a capsize. And if partly deflated they would also create a nice padded cushion for the bow section to sit on when nested. Hopefully what I'm describing makes sense- if not I'll show off my MS Paint skills :D:D

I've used chisels extensively to trim off high spots and tape edges, but you need a steady hand.

Looking good. The other way I've seen to add buoyancy to the bow section is to build in a compartment amidships encompassing the centreboard casing. I've wondered about how the boat will cope when swamped. Buoyancy bags fitted low down in the bow section might be another approach.

I feel like I'm very close to opening the paint tin now. Still some final sanding to do, and a couple of places that would benefit from a bit more epoxy. The underside of the gunwhales being the worst culprit. Maybe I should make the cut-outs for the self bailers now, so that I can epoxy seal the edges? Rather than doing it after painting? Anything else I am best off doing prior to painting?

Well before reading Graham's reply I had already prepped the area, sanding back and putting a bit of a radius on it. So I decided to bash ahead and have a second go at taping it. Given how badly my first attempt went, I didn't want to take any chances. I made up a set of formers to hold the tape in position- two plastic wrapped pieces of ply for inside the slot, held in place with wedges, and two battens to hold down the other edges against the bottom of the hull. Securing these took a lot of messing about with clamps and straps. With everything set, I applied the wetted out tape... and it just stayed nicely where I wanted it, no signs of it trying to lift or for any bubbles to form. So I didn't bother with all the battens, clamps, etc etc, as that would just have disturbed it. Ah well, no doubt if I hadn't gone to the effort, it wouldn't have wanted to stay in place!

So... I wanted to tape the edges of the centreboard slot. For whatever reason, I just couldn't get the tape to lie flat, and ended up removing it before it cured. That was the last of my second 50m roll; I'm looking at about a week delay to get any more. I think the problem was probably that I didn't put enough of a radius on the edge of the slot. It's a very fiddly little job, and I don't think the instructions specifically said it was necessary- did anybody else try taping here, and is it ok to just move on without doing it?

Great progress. I didn't think you were going to use a cradle, until I watched it descend from the ceiling like a Mars rover. Very good!

The self bailer flap won't seal perfectly if it's been damaged in any way- in my experience you need to pull the bailer closed when below self-bailing speed, otherwise water will seep in to the boat.

I've not completed my Spindrift yet so cannot comment specifically, but I have done quite a lot of sailing on dinghies equipped with these bailers. They are really designed to keep up with green water and spray coming aboard in lively conditions. And they do that very well indeed. You need to be going pretty fast for them to work- in fact when going too slowly they can let water in, so you generally only open them when going upwind at a good speed. I don't think you'd ever have a significantly higher water level inside the boat than outside. The boat will be designed to float when swamped with the centreboard case out of the water- otherwise it becomes unrecoverable. Opening the bailers on a swamped boat that isn't moving won't do anything, and my gut feeling is that it could be counterproductive. A swamped dinghy cannot be sailed fast enough for the self bailers to work. You'll need to bail some of the water to lighten the boat, then run off on a broad reach and let the bailers do the rest. All this time you'll have almost zero stability due to the free surface effect. Unless you are an Olympics-level rower I don't think you could row fast enough for bailers to work. My experience is on large traditional dinghies like Wayferers, and some more modern open transom types which don't really count for this discussion. Perhaps the Spindrift behaves differently, but the laws of physics are the same so I guess not.

That's a good milestone passed- the centreboard casing is in place, marking the last major piece of hull construction.

Well I couldn't put it off any longer and last night cut the slot for the daggerboard. Just as daunting as when I sawed it in half- it feels so wrong to take a good solid structure and take a power tool to it! I used an oscillating multi-tool which was perfect for the job, no breakout and a nice neat cut. My building platform yet again proved itself useful. I can sit the boat up on its side; the slots for the keel in each cradle are also the right size for the gunwhale. The boat balances perfectly like this, but a couple of clamps help guard against an an accidental knock. Being able to easily work on both the inside and outside was very handy when making the cut for the slot, and put everything at a convenient height without having to climb into the boat. You'll see in the close up photo of the slot that I have strips of plastic between the hull halves. I have filled up to these with micro-fibres, to help create a sharper edge on top of the taped seam, which of necessity is rounded off. This should give a seamless joint between the hull halves.

That's good to know about not needing to paint inside the casing. I have a very good layer of epoxy on there, two coats on top of the filled out weave of the cloth. One downside of painting it would be that I couldn't add any sort of fillets inside without the epoxy going on top of the painted area. I was given a tip to form fillets inside the casing by using a dowel to smooth down the epoxy, sounds a little fiddly but perhaps worthwhile. The paint I'm using is this stuff: https://www.smlmarinepaints.co.uk/topcoats/lustre/LustreGlossPolyurethane I'll have a good read through the datasheets etc. My workshop is easy to ventilate (windows on both sides, and it's currently blowing 45kt here) but I'd be worried about any odours becoming impregnated into the building. Once the boat is finished I need to turn it back in to a house! I've been fairing the inside as well, just because it seems a shame not to. I'm not aiming for perfection but I figure that a smoother surface will be easier to keep clean, and sharp edges and corners are where the paint is going to get chipped and abraded.

Quick question: I'm about to put the centreboard casing together for final assembly. Is it worth painting the inside first? It's been glassed and a good coat of epoxy over the top. I quite fancy painting it as I'll never really get another chance, and it will give me a good opportunity to see how the two-pack paint handles. The downside is that it will delay everything by a couple of days, and the time I have left in my workshop is limited.

Fairing, sanding, and coating does seem to take an eternity! But I am getting there. I made the decision to add bilge strakes, which are not on the plans. I think that these will provide some extra protection to the hull, as well as stiffness. I am going to be adding lifting eyes and will through-bolt them into the strakes. It's harder than you think to mark a line that is parallel to the keel- not quite as simple as just measuring a set distance down the hull, because of the rocker. I opted to just have the strakes on the stern section. Each piece of ash, after planing to shape, weighed about 350g, so they will be adding less than 1kg to the finished weight.

Also the lifting points are down on the floor, so perhaps the force on the bulkhead is mostly compression... I think... but I am an not an engineer and don't even play one on TV (although I do work on and drive boats for a living...)

I see what you're saying but doesn't that depend upon the distance between the davits? I've not fitted mine yet so I can have them further apart than on Graham's drawing.

In my post above, I mentioned that I was considering adding bilge strakes- primarily to reduce wear and tear on the bottom of the boat. Well tonight watching Sailing Florence, I spotted that their S9N has these. Theirs are pretty long, reaching the transom, and are further inboard (closer to the keel) than I had envisaged. I like the idea of through-bolting into these strakes to create the aft lifting eyes- the load would be spread right across the bottom of the boat. I'll probably use something like 19x19mm ash for the strakes. This would probably put the rear davit eyes slightly further aft than Graham showed, maybe around 12 to 18 inches, assuming I want the eyes coming through next to the aft seating. Or I could move the strakes further away from the keel. I am planning to use a small Bison trolling motor on the boat and that extra weight on the transom concerns me. Moving the lifting points slightly aft feels like the right thing to do... although I don't want to put extra stress on the nesting joint. I suppose it's a trade-off. And I guess the forward eye would have to move a similar distance forward. Would be interested to hear any thoughts on this plan.

Question: second coat of epoxy is on, and there are some runs/curtains. Do I crack on with the third coat within the overcoating window, and then sort everything out afterwards? Or should I stop coating, wait for full cure, flatten everything off and key,then do final epoxy coat? Obviously I'm inclined towards the first option! Thinking that everything will need flattened back ready for sanding anyway.

That's the outside faired and first epoxy coat applied. I said all along that as a utility tender this boat would not have to be pretty, and I wouldn't spend a lot of time on cosmetic things like fairing. So why have I spend the last week doing just that I suppose I'm this far in and I can't stomach the idea of seeing all the taped seams through the paint. I guess I have a bit of pride after all! I've decided to go with a 2-pack polyurethane paint finish, in the scheme of things the extra cost is minimal and it would be daft not to take advantage of having the boat in a dry, warm, environment for the job.

Graham, thanks for that. My own anecdote about the dangers of davits is that a large yacht local to me got caught out in heavy weather. Their console RIB complete with outboard ended up swinging by one strap, sweeping the cockpit at head height. It took a very well timed scramble up the davits to cut it free. Terrifying. We only plan to use the davits for overnight storage and shorter day sails- if we thought it was a viable permanent option we wouldn't have chosen the nesting dinghy. We do indeed intend to sail her. I have an old ex-club dinghy that I am stripping parts from, so I already have the two Andersen bailers that I'll need, along with rudder fittings, cleats, blocks, etc.

Thanks for the update, and thanks for being brave enough to try something different. How do you think it would have gone if you had glassed one side only of the core, then formed the hull?

Thanks Graham, that's perfect. Similar to what I had first thought of, although I had considered using the front face of the aft seats. Another thought was to add rubbing strakes near the chine, and through bolt to those, to help spread the load over a bigger area. My yacht is 39ft and 13'10" in the beam, any smaller and the 11ft Spindrift would look pretty silly up there.

So, I appear to have run out of glass tape, there will be a slight delay as I wait on another roll arriving. Does this mean I've been glassing places that I should not have?? When I installed the keel, I used stainless screws every 6". But to be honest I think it looks pretty nasty and I would like to hide them. Covering over with thickened epoxy and a layer of tape would do, but it's all extra weight. Maybe I should just remove the screws and fill the holes? The keel is faired to the hull with fillets, I was wondering about glassing over these as a precaution before removing the screws. I understand there's not a lot of point in glassing the underside of the keel itself, better just to add a keel band.