tiki 30 beams for 26

[paul anderson]

hi everyone i have just read scott williams latest excellent blog and he suggests making tiki 30 beams for the tiki 26 as it is far less complicated to glass and all the structural bits are inside the beam itself.any help or suggestions would be appreciated as always.

cheers paul.

[boatsmith]

I would add that the tringular shaped beams take away useful space. The aft beam if rectangular makes a great seat. The mast beam also makes a better seat and also provides a safer place to step than just a narrow top. I have the triangle beams on my T30 rectanfular beams on the T8ms I have built. My next boat will have rectangular beams as well made of divynicel foam and carbon/glass fiber. JMO

[Thomas Nielsen]

It seems that when a Wharram fails, it fails at the beams. Here are some thoughts. If there is a place to over build a wharram it's in the beams. Really, how much weight can you actuall add here and sink your boat!? Some ideas - make then out of aluminum (I am contemplating having one made up this way just to see what it looks/feels like.). Go to your local housebuilding lumber store and get a couple of Doug Fir glulams, get the pressure treated kind and then wrap them in glass - sure they will be a bit heavy but will you be able to break them. One thing I noticed when I built Tsunamichaser was that once I finished the hulls I wanted to be done. I built the beams carefully to spec but the idea of splicing plywood for the web well I think about that when I'm out sailing!

[paul anderson]

thomas you have made an interesting point and i would have to agree with you on the idea of over engineering the beams for a weight penalty that really is not much in the greater scheme of things.p.s what exactly is a glulam?

cheers paul.

[Thomas Nielsen]

A glulam is an engineered wood beam made up of multiple layers of timber. They are used in house construction in North America and can be bought in many differet widths and depths

[paul anderson]

thanks thomas,so are you suggesting to forego the whole beam as designed for a solid laminated one,or to incorporate the glulam into the existing design?

cheers paul.

[Thomas Nielsen]

I have been thinking about building a standard Tiki 26 beam and then to do a load test to failure just to see. This of course instantly raises questions about static and dynamic loads and where to apply the load. Also I built a temporary beam last summer out of 2 2x4 and a 2x6 screwed together while I worked on one of the beams from TsunamichaserLast summer when Scott Veirs launched his Tiki 21 we "took" it apart at sea, well 10 meters off the beach. Not a pretty thing. So between that and the failure of a couple of Wharrams, one in NZ and one in England and these musings I've been thinking about beams some. Really what I should do is stop working and go sailing!!

[kim whitmyre]

I haven't built a tiki 26 beam from scratch, but I did take the front beam off to repair a locating pocket for the deck pad for said beam. While it was off, I took it down to wood and applied fiberglass and epoxy, something that should be done as a matter of course. . .ahem.  I am also a woodbutcher (carpenter/cabinetmaker, etc.), and the tiki beams as designed are hard to improve on, imho. Lightness is much appreciated, without a doubt, but make it so light that you win all the "races," and your cruising safety may suffer. Choices, yes, so many choices.

 

My front beam appears to be using Spruce for the solid wood parts, not Douglas Fir: much lighter. With the application of fiberglass/epoxy over the whole assembly of wood and plywood, it is very strong and resilient.

 

 

[Scott Williams]

Hi all, I regret that my post regarding the Tiki 26 beams may have been misunderstood.  I don't have any doubts about the strength of the Tiki 26 beams as built to plans.  I used good Doug fir for all the structural members and I'm glassing all exposed surfaces (solid wood and ply) as a precaution against future checking, which in my experience is common in these beams, leading to eventually rot, especially in the plywood fairings. 

 

My point about Tiki 30 beams is that they are a later version of the Tiki 26 beams.  Still the same shape and similar structural design, it's just that they are put together in a different way, so that most of the solid wood structural members are enclosed in the ply wood fairing, web and bottom plate rather than external.  Having built beams for both boats (mine and David's Tiki 30) it's obvious which construction method is easier and faster to build and which is easier to sheath in glass.  As Thomas says, by the time you get the hulls done, building complex, time-consuming beams is no fun. 

 

I didn't suggest that I would use full-sized Tiki 30 beams on a Tiki 26 (though I suppose you could).  I  meant that if I were doing it over again, I would build them Tiki 30 style, scaled down to Tiki 26 dimensions.  It should go much faster and be as strong, look as good or better, etc. 

[Thomas Nielsen]

I have no doubt that the beams I built for Tsunamichaser are plenty strong enough but the quantitative yet experimenting engineering side of my brain is always asking what if? It would be interesting to build a beam and then load it to failure. Things going for the beams are the short span relative to size and the fact that they are attached at two points on each end. This limits the effective flexural length to about 7 feet. I think if there is one area to stay on top of maintenance with extra attention is the beams. Other beam ideas - jungle beams made up of many bamboo poles all lashed together and lashed to the boat.

[boatsmith]

The beams and the beam attachments do seem to be one of the first areas to show signs of deterioration on Wharrams.  Routine inspection and and maintenance of these parts is a god idea.

[paul anderson]

well thankyou for all the responses,the consensus seems to be that the beams are fiddly to build and need to be carefully looked at during maintenance,also the beams as designed seem plenty strong.

cheers paul.

[Scott Williams]

I think I'm going to take the precaution Boatsmith suggested on the phone the other day and laminate a few layers of uni-directional carbon fiber tape on the bottom plates of the mast beam.  This is the area under tension from downward pressure of the mast, and from what he has experienced and what I've seen on my Tiki 21 and Hitia 17, it's uncertain how much good that short dolphin striker does to distribute the load out to the hulls.  The carbon will barely weigh anything and may make me feel better when hard-pressed offshore.