Sunday, 29 July 2012

Some arrangements for fitting a storm jib.

I am going to a lot of trouble to give the boat a storm jib, mounted on a removable inner forestay. I think a storm jib is a sail that is often left in the bag on a boat - few people use them. But I have sailed all the way from the Canaries - Madeira - the Azores - UK under storm jib for 95% of the trip. I had wind on the nose varying from F6-8 all the way. I'd gone as far west as the Azores to pick up the south-westerlies to get me back to the UK, and did indeed set off from there with a fair wind, but it only lasted 12 hours. Then I was back to the storm jib and either double or triple-reefed main all the way to Start Point, all of it close-hauled.

I had an inner forestay on that boat (a plywood 32' monohull) which I'd fitted specifically for taking a storm jib but I did experiment with hanging the storm jib from the main forestay, to see how it might work. I could go to windward alright, but at only 2-3 knots. Hanging the storm jib from the inner forestay, so that it just about overlapped the reefed main, I got 6-7 knots. For two weeks crashing through waves all the way from the Azores, I was very glad to have that sail and that rig.

Besides allowing me to continue sailing at a reasonable speed in strong winds, the storm jib also allows me to sail slowly in lighter winds - to await daylight before entering a new harbour, to catch up on some rest, or to go fishing. I have already fitted a catwalk between the front aluminium beam and the front of the saloon, but I need bobstays to counteract the upward pull of the inner forestay.

The bobstay fittings that were previously used for the front beam were no use - they were fitted too high for one thing, making the angle too shallow. And the support inside the hull was inadequate too:

In the bows of the boat, a floor is glassed in about 20 cm above the water line. A block of wood has been glassed onto the wall of the hull at floor level to take the load of the old bobstays. I don't think this is strong enough, or low enough. The yellow area behind the text in the image above is a hole I dug through the floor and through the foam that fills that area to place a new load bearing construction.

I used a grinder to cut through the floor - which was surprisingly substantial - an Airex sandwich. And then a wire brush on a drill to pulverise the foam underneath with a hose from a vacuum sucking away the dust.

It would be crazy to do such work in such a confined space without the benefit of an air-fed mask:

These masks sell for £6-700! I was lucky to find one at the local dump, and acquired it for £3. It had no battery and the exhaust valve was ruined. Replacement parts are also very expensive, so I had to adapt it a little. A 6v battery charger wired in to the motor runs the fan, and a vinyl glove with the ends of the fingers cut off works like the valve. An old filter cut down and glued to a flexible pipe allows me to work with either filters or a tube leading to a supply of fresh air. The fan is a bit noisy, and I feel pretty constricted working in it, but I get fresh air to my face and so don't have to breathe either fibreglass dust or epoxy fumes. Ear defenders and a set of plastic overalls for epoxying add to the discomfort. I'm also working in a space where I can just about sit up... but that's enough wingeing! Back to work!
I glued a pad of plywood to the surface of the inner skin of glass with epoxy and fillers. I then glued in a plywood floor, and plywood to the front and back of the hole. I filleted the joins, and glassed it all together with epoxy and biaxial glass. From the outside, I ground away the outer skin, and the foam underneath, and filled the hollow with many layers of epoxy and glass:

In this way, there is no foam where I will attach the bobstay fittings - just solid glass and epoxy. And the load is spread between the outer skin and the inner skin, and via the plywood construction to the inner skin of the other side of the hull. I will use a stainless steel backing plate to spread the load of the nuts of the fitting evenly.

I think this structure is so strong it would be suitable for attaching my anchor bridle too, which I'll bear in mind when choosing the fitting I'll use here.

Phew - several days work grinding and epoxying to create a thing probably no-one will ever see or appreciate, except you reader! Thanks for your attention!

1 comment:

  1. Thanks for documenting your work. As someone who occasionally mulls over the idea of home building, it's educational to see the bits that might come later. Particularly the last post with the moisture removing tricks.