Aluminum tube sectioned mast

I'd be reliant on finding one that is a two piece which would need a bit of luck. However, I did find a German site that sells hobie parts which has a kit for doing this. It runs about $200 but it would really simplify the project.

 

21 feet, diagonally.

 

Scaled roughly off the web page image it looks as though the hounds are about 20 feet up the mast, so sticking with the 2 piece idea why not just make the second piece the top 6 feet? That way your shrouds, trap wires and jib halyard can terminate at the top of the main portion, which will fit in the garage. You would still need some sort of sleeve/plug arrangement to slot it in the top, but I don't think it would need to be as strong as if it were in the middle of the mast. An external main halyard would be KISS on such a set up.

Thinking further; I wouldn't even necessarily worry about a sail track for such a short length. You could terminate the bolt rope at the hounds and just haul the peak of the sail (it would probably need a length of dyneema sewn up the luff at this point) to the top of the extension. Tension the cunningham and off you go. The advantage of this is you could probably just use a piece of carbon tube for the mast extension, and if aesthetics are important add a foam fairing so it matches the alloy section. If the join ever fails it will look a bit silly, but shouldn't bring the rig down.

 

That sounds like a great idea. I'll want to double check the figures for the height on the hounds/trapeze and go and measure my garage to be absolutely sure, but assuming the numbers work out, this may be the best way to do it.

My only concern is getting a snug fit for the internal sleeve due to all of the rivets poking through the mast where the shrouds and trapeze connect, but I'm sure I can find some kind of workaround.

 

You can use those rivets to hold the lower side of the sleeve in place. The halyard tension will keep the upper section from sliding off.

 

That is a really good idea. I think is still want to use a cotter pin on the top section to prevent it from twisting independently of the bottom section.

 

This is idea appeals to me if the 20 ft mast be made to fit into the garage diagonally that is 21ft..?
The extra buoyancy from foam which could be shaped to resemble a wingmast and the light weight of carbon may add to performance and help avoid full capsize ..

 

Emailed Richard and he suggested possibly making the joint between the spreaders and hounds due to that spot on the mast being stronger but less under stress. He mentioned diamonds, though I wasn't aware that the H16 had diamond stays.

 

Hi. I’m reading this post a little late. Clearly. I am in Beijing and sailing is just taking off here I think. I built a Quattro 16 cat and a Zest dinghy; both designed by Richard Woods. I haven’t been able to find a mast here. I went with aluminum extrusion tubes after trying carbon fiber and epoxy resin. For the aluminum I used tube with 2.5 mm wall thicknesses. For the Quattro I used 76mm outside diameter and for the Zest I used 60 mm outside

The tube comes in 2.5 meter lengths. I used inserts 600mm long. Outside diameter of inserts being 2 mm smaller than inside diameter of the mast. So there is a gap of 1 mm between the 2 pieces. Epoxy resin to fill the gap and hold the pieces together.
I mixed the epoxy resin then added silica sand to add strength. Resin by itself will not hold, usually doesn’t adhere very well to aluminum. Once the silica is added you get sufficient adhesion and strength. I made sail-ways out of smaller tube. Bolt rope in the sail. The resin mixture for gluing the sail way to the mast I added silica until the resin is pasty but still workable.

As test for strength I took a 1 meter length of the larger diameter tube and glued a smaller tube to it. After a few days I beat up a block of wood with it. It holds completely. I supported the ends of each mast and sat in the middle of each one. Each mast holds my 100 Kg weight with some flex but no bending. I have the dinghy sitting in a lake and have had the sail raised for several weeks now. No problems.