A Photo & Discussion Forum for Wharram Design Enthusiasts
Okay. Please correct me if i'm wrong on any of this.
I'm looking for masts for my Tiki 46. I would prefer aluminium but i cannot find 7-8 inch diameter with a 3/16 wall anywhere in north america. (except from a couple of flagpole companies that will not even return my call when i mention i'm looking for a mast. They wouldn't even sell me two lower, untapered, sections that were the exact right dimensions. I even had a friend who worked for a tent company try to buy the lower sections and they refused!!!)
The closest i could get is 1/4 inch wall but that weighs 345 lbs for 48 feet (need extra for 2 splices to make 42 feet, as they usually come in 20 foot sections)
So i resigned myself to build the two masts out of douglas fir using the birdsmouth method. I figured i needed about 150 bd ft of douglas fir per mast and THAT weighs anywhere from 2.2-2.5 lbs a bd ft, making the total weight anywhere from 330 - 375 lbs?!
That seemed like a really heavy mast and was the reason i didn't go with the 1/4 inch aluminium tube in the first place, so is that a reasonable weight for a mast? and if it is i might as well go with the aluminium tube at 1/4 inch.
Any suggestions? It's been keeping me up at night and i've even bought a used regular monohull type mast but i can't bring myself to use it. (the gaff and sleeve wouldn't work anyway)
On Peace IV we have wooden masts made of mast quality (fine grain no knots) Douglas Fir from Canada. Peace has done over 50,000 miles with no trouble. Our masts were made by Nobel Masts in Bristol because of Nev's allergy to epoxy at the time. They weigh too much for us to even lift them. I find that comforting. They are plenty strong and needed to be that strong on several occasions. Peace can do 16 knots and that is plenty fast considering how over loaded she always was. You know all about that though!
Alloy or wood. Get 'em strong.
When we were visiting John James in Rhode Island last month, he was building a wooden mast using bird's beak construction and it was not hard. But his boat is a Tiki 30 so that is more light weight than your two Tiki 46 masts will be. However, it is not difficult. John and I and a friend had a pleasant but busy morning gluing them and fitting the glued pieces together in a cradle and then John and Nev planed and sanded and it became satisfyingly round and lovely. It is an interesting project.
We fiberglassed our masts and had a lot of paint on there too because we wanted to minimize problems and maintenance aloft at our age.
Mike, it is just great to see this project come to completion. I had hoped to sail our boat with yours one day, but Peace is now for sale and there is lots of interest. I am sure you will be delighted to see those sails curve to the wind and hear the bubbling and chirping of the water as she glides along effortlessly in even light air. It is a great design! Ya done good!
Love, Ann and Nev
okay, the 24' sections just arrived(4 of them) The question i have is stainless or aluminium rivets and 3/16 or 1/4 inch? super excited to have two masts by next spring.
Ah,! Mike, that is wonderful to think about... You will turn off the motors and then raise the sails to the wind one by one until she is powering along with only natural sounds. I loved the way the sunlight played with the water surface and the wind and water. And then Peace came along and played with all three and took us out into the ocean life again. Magic!
Very exciting Mike..
Are you going to keep to the 12m height or go slightly longer? and where will you make the splice, at the bottom end or the top? Hope you post pictures of your progress as i'm sure everyone would love to follow the process..
For what its worth i think that aluminium rivets would be best to eliminate any galvanic action, but i'm sure someone with more experience on mast making will give advice.
Just chucking this idea in here............it is something I thought about many years ago, meaning to give it a try if ever I needed a low budget aluminium mast with a constant section. But now that it looks as though I may never get around to using the idea, and maybe someone else might give it a go. Aluminium is great for a mast surface, especially if for a sail like a soft wing, but is too prone to bending and fatigue for my liking. So I would prefer a composite laminate build-up inside the ally tube......This could be created by pulling long fibres into the tube and which are held in place with a vac bag on the inside. seal the vac bag after folding it back over the tube ends and infuse epoxy resin into the laminate. A recirculation resin infusion molding process would be best to make sure of complete saturation, before applying full vacuum to the bag and bleeding out excess resin.Welding together a number of thin wall tubes would make the length required, without too much worry about structural weakening due to the weld, because the composite laminate inside should be calculated to provide the main structural strength.