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As part of my winter long makeover of Duckie I have begun to make a new lighter gaff.  I added four inches to the measurements from the plans to give me a bit more space to attach things like flag lanyard.  I also abandoned the gaff jaws that the plan lays out in favor of a 3/4 inch plywood jaw plan that will include the plastic fender I made to keep the jaws from catching on the shrouds as my current gaff is set up. 

The most interesting thing about the gaff is that I made it with a cooper layup.  I found Andrew Linn's article about how he makes cooper layup masts and followed that.  It turned out to be amazingly simple and easy to laminate.  It was very much easier to assemble than the bird's mouth masts I have assembled and came out equally as true along the length.  I reinforced it at the ends, nine inches of dowel at the jaw end, six inches of dowel at the halyard block, and another six inches at the other end.  I didn't pay too much attention to the diameter of the stick because I didn't think a little bit here or there would make a big difference its performance or strength.  As it turned out, the stick is 1 1/2 inches outside and 1 inch inside diameter.  This made it so that I could use a one inch dowel as the caps and reinforcement.  I glued the whole works up with epoxy.  After the glue set for a couple days I ton tested it with my considerable bulk aided by a little leverage and satisfied myself that it won't break under normal usage.  When it is all said and done I expect that it will be about 40% lighter than my current gaff.  It should float like a cork.  I don't know if I will be able to feel a difference in performance,  but I bet I will feel a difference when I haul up the main. 

So far it has been a fun project and not difficult at all.  If anyone is thinking about it I suggest you give it a try just for kicks.

Al

Any weight reduction that high up in the rig will be noticeable when you sail her. The problem I have with the cooper style of mast building, is stave alignment during the process and of course the difficulties, if you want to taper the staves. Most gaffs that I design have double tapers. The gaff end is usually tapered down a bit, the middle of the gaff is fatter and the outer end is also tapered a touch, so making the 22.5 degree edges on a table saw isn't practical , though I guess a router table jig could be arranged.

Way to go Al, looking forward to some pictures and reports of her sailing qualities, which I'll bet you do notice, especially in very light wind strengths.

Thanks Paul, I'm pretty pumped about it.  I wasn't kidding about how easy it was to do.  I agree that it wouldn't be easy to taper one of these things.  I am still trying to figure out the best way to taper a birds mouth layup.  I may not build a birds mouth mast this year, because I have four boats to finish up this spring, but I am going to build one for Duckie eventually. 

It is going to be interesting to try out the enhancements I am making this winter. 

Al

I just built a tapered in both directions birdsmouth mast. The staves started as 1x2's, ripped from a couple of lengths of white spruce. I then make a tapering jig from some aluminum angle stock and some 2x4's. I blocked up the staves 4 at a time, inside the tapering jig and using a power plane, whacked off the stave thickness dimension. This was to be 3/4" at the base to 1/2" at the head, but starting about 3' above the goose neck, to improve stiffness. Next using the same jig, but realigned and with the stock reshimmed, I cut the sides of the staves down, first from about half way up the luff to the head and again from the partners down to the heel. This makes the shape of the staves correct, so it'll have a taper from the partners down and the mid luff up.

With the tapered staves, it was pretty easy to set the table saw to make a dado blade cut for the notch at 45 degrees. Using a dado blade saws having to make two passes through the saw. So does using a flat bottom (flush cut) router bit. Setup on the saw is important as the stock is pretty small and will want to dance around unless you have good feather boards and an outfeed table. The dado cut was made on the same side of each stave. I used a symmetrical notch layout, so the bottom of the mast would have a true octagon shape, which is easier to fit into partner wedges. Above this I rounded the stick (starting just below the gooseneck) on a home made, 22' long lathe. The lathe is a relatively new thing for me, and really speeds up rounding over a mast, but I've done plenty by hand without a rotating mast. Rough it in with a belt sander, maybe a hand plane then fine tune by hand.

My primary concern with a cooper built, stick is the glue surface is reduced 33% over a asymmetrical notched birdsmouth.

Yah, I thought about the scanty glue surfaces in the cooper layup.  That is why I ton tested it before I put too much time into it. 

I got the whole thing assembled yesterday when the temp finally got above zero.  I doweled the jaws to the stick so that I wouldn't need a bolt to support the assembly.  The 3/4 inch plywood I used for the jaws is pretty rugged stuff so I doubt that a failure in the jaws is likely.  When I rounded it off I was careful to take only just what I needed in order to keep the glue joints as full as possible.  I have hefted canoe paddles that weighed about as much as my gaff does.  Granted they weren't the highest quality, but I swung them all day anyway.

When I make the birds mouth mast, I will probably not taper it at all until I get above the top of the gaff travel.  I want the sail to fit as snuggly to the mast as I can get it without monkeying around all day adjusting the lacing.  I also figure that a fuller mast will float better in the event of a capsize. 

I'll get some photos of what I have been working on when I get a little farther along.  And that is totally dependant on the cold. 

Al

test

The previous post is a test to see if I can post pics to this board with the new setting on my camera.  Apparently I can.

The pic shows the changes I made in Duckies' cockpit last winter.  You can see the bridge deck as well as the commercial hatch covers I bought from Duckworks.  I think these changes will help me a lot in various ways.  Now that it seems my tech is compatible with this board, I will post additional pics of the other things I have done last winter.

Al

Looking forward to seeing your work Al, that cockpit is pretty sweet btw!

Regards,

  Will

Getting back to the gaff,

Here's a couple of pics showing the construction of the gaff.  The first one is the piece I made up as a proof of concept for the cooper layup.  I laid the strips together with just the hint of a gap between each of them and the taper down.  I then laid a piece of masking tape across both ends and when I rolled it up, it looked like this.  I wrapped it with electricians tape to pull it tight and there you are.  When I did the actual gaff I used zip ties to pull the whole thing tight, but I still used masking tape every 16 inches to hold the strips together.

As I wrote before, the jaws are made of some 3/4 inch plywood scraps I had laying around doweled to the shaft and epoxied.  I may be wrong, but this seems to be quite a bit stronger than the original jaws that the plan called for.  It is certainly lighter.  The yellow fender screwed to the front of the jaws is my answer to the jaws fouling the shrouds.  The jaws still contact the shrouds, but they don't get hung up. 

Al

Oops, apparently I over wrote the first attachment.  Here it is.