Warren's Build Log, CAN 573

[Warren Nethercote]

I have always had a bit of a leak in Blondie, probably around the keelbox, but it's buried under 'berth flats' and hard to access. One day .... Until then the underdeck volume tends to be a bit fetid, so this year I added a couple of cowl vents. The aft one was easy - I just bored a hole in an existing hatch to fit the ventilator opening. Forward I needed to run a tube from the foredeck to the cockpit sole to access the below-deck volume. A 100mm pipe would have been ideal, but this is inches country for building centre pipe.

I wrapped a cardboard mailing tube with bubble wrap to bring it up to diameter and laid up 2 layers of 6 oz cloth, a single layer of 14oz uni, and two more layers of 6 oz cloth, all glass. Cutting the glass tube to fit between the deckhead and the sole was fun and I can't vouch for the beauty of my filleting.

The cowls get replaced by blanking plates when we sail. Time will tell as to effectiveness.

[Tim Ford]

Interesting.

Folks may remember my mentioning I have the same issue. It's well ventilated but I'd still love to find the leak and fix it.

Any thoughts on where your water ingress may be located, Warren? Mine fills dedicated empty spots on both side of the keel box. Without tearing everything out, I'm at a loss as to how to address the issue....sheesh.

Luckily the boat is dry-sailed.

[Warren Nethercote]

Mine is more of a seep: a litre a day maybe and less as the leak path swells up. If you review my build log you will see that I prefabicated the keel box, including a 'pad' at its bottom to double the bottom thickness in way of the cut out. I think I didn't get enough thickened epoxy on that pad when I glued on the bottom planking. I need to cut a few more holes in the berth flats to access the edges of that pad. The forward end of it had clear voids. I also did my best to seal the edges of the keel cut-out in the bottom skin, but was my best good enough? And it might be somewhere else entirely, but I doubt it.

[Warren Nethercote]

Update on the cowl vents - they seem to be effective in holding the below-deck humidity down.

[rballentine]

Hi Warren
How well does your spinnaker launcher work? I am considering something similar. Any changes you would make if building it again?

Great photos and description of your build! Thank you!

Roy Ballentine

[Warren Nethercote]

Hi Roy,

Initially we struggled a bit with the launcher. It worked well with our 29M2 A3, but quite often choked on our 40M2 A2. The A2 generally went up well but often hung up coming down.

Two years ago I modified the deck opening by increasing the radii everywhere the chute 'rubs' and after that the A2 went up and down quite well.

But we also got a new, 33M2 A 1.5 that proved to be just like Goldilocks' porridge. Juuust right. It is a lighter cloth than the A2 as well as smaller, so goes up and down really well, and is effective across a broader windspeed range. Our crew weight is often under 450 lbs so the 40M2 A2 was often just too big for us in afternoon sea breeze conditions. I do wonder about the monster chutes that many people have, but then again, not everyone is blessed with reliable 10 to 12 kt sea breezes.

Our A3 sees little use after acquisition of the A1.5, since the A3 doesn't like to go very deep at all.

(Edit - here is a picture of the A1.5, from another computer)

Note of caution: since the halyard tail is the recovery line (like a 29er), rigging is picky and whatever spinnaker we rig is going to be what we use all day.

[Warren Nethercote]

Supplemental to the last: I neglected to mention two things. First is the importance of the recovery sock and specifically its size. I will add an edit with dimensions. It took three attempts to make one 'fat' enough so the sock could swallow the pig without choking. And if I were to build again I would use skiff sheeting for the main rather than a centre traveller because the traveller compromises sock length and placement.

Finally, recovery has to be fast - take up tension on the recovery line, blow the halyard cleat and pull like mad on the recovery line. If you go slow the chute gets in the water and you are toast.

[rballentine]

Hi Warren,
Thank you for your reply. If you can stand it, a few more questions. For context, I am likely to be sailing single-handed much of the time. My other rides include a Corsair 760 and an iFly-15 foiling catamaran, both of which I sail solo. The Corsair has a giant spinnaker, which I have arranged to fly solo.

1. What dimensions do you recommend for hole in the deck for the launcher? I am thinking about putting mine just behind frame 18. As you know, there is lots of room there.
2. Dimensions and other recommendations for the sock would be really helpful, please.
3. I am surprised by your comment about the sock interfering with the main traveler. The sock comes that far aft?

My hull is still completely open, so I can go any way I want with the above issues, but not for much longer....unless I delay construction during sailing season.

Thank you!