A Photo & Discussion Forum for Wharram Design Enthusiasts
Hi - I need to replace my beams and prompted by this plan to make baot really trailerable eg replacing cockpit with netting.
- anyone any experience of aluminium beams - specifications/design?
- tube or maybe a box girder made of angle?
- anyone know who could specify this for me?
- anyone got a netting cockpit?
I did see a aluminium "H" beam on a Tiki 26. I think the builder said that he used the same specs as the wooden beam but buildt in alum.. I will send a pic when I find it. Rory Tiki 21 had netting for cockpit/deck . I believe netting was under a trampoline.
Thank you - they look very smart but I guess not much lighter - quite a lot of aluminium in theme! Yes I have seen Rory's tramploline
I don't know if you are still interested: this advert http://www.kijiji.ca/v-sailboat/oshawa-durham-region/catamaran/1109... mentions aluminium beams and you can see on the pictures that the owner replaced the aft beam with an I profile and the front beam with a tube.
I would be interested to know about the specifications for beams made out of aluminium tubing for the Tiki 21 or 26. It is interesting to see the Mana fitted with 2 square beams under each mast and no other beam. Obviously there is less compression on the mast beam without a jib. Their sections are about 6"x6" and 6"x12". Wharram has used glulam solid beam then I-beams then triangular beams before using square tubing. Any comments? Thanks
i have a Tiki 26 and would love to replace beams for aluminum, how did you get on finding out specs?
Sadly sold my Tiki 26 but had always thought you could make an open box beam with aluminium angle and ply - a new product I am using is "ply" made from recycled plastic - comes in standard 8x4 sheets and 19mm or 9mm.
So if you will homemade composite - use angle for edges and the plastic ply for sides - maybe rout out holes for weight reduction, and maybe some verticals in aluminium - a bit like you see on scaffolding sites.
Gone mono - Signet 20 designed by american Ray Kaufman if anyone has info! Its a £500 ebay project....
but thinking of converting to cat ketch with wharamm style sails
According to Aluminiumwarehouse.co.uk it's an industry name for 6082 T6. The 6082 refers to the chemical composition of the alloy, and the T6 refers to the heat treatment it is given to achieve the desired mechanical properties. It's quite a common alloy, I think it's the sort of material aluminium masts are made from. The following comes from their website:-
Also known in the metal industry as H30, our Aluminium alloy 6082 is a medium strength alloy with excellent corrosion resistance. It has the highest strength of the 6000 series alloys. Alloy 6082 is known as a structural alloy. In plate form, 6082 is the alloy most commonly used for machining.
Of the varieties of aluminum, probably the best choice for this is 6061 T6. It is tough and forgiving, and fairly resistant to corrosion as well as to fatigue.
Personally I feel aluminum is about the worst possible choice for something of this nature. It is extremely reactive and subject to electrolysis and electrolytic corrosion. It also has a far shorter fatigue life than wood, so if there is any flexing and bending, it will eventually end up with fatigue cracking. Wood, if you choose quality wood and build well is the most reliable of all materials structurally. Choosing the right wood, and using the right construction methods and protection, matters of course. My personal choice for this kind of application would be good quality knot free close grain Douglas Fir.
I've worked with metals all my life, welding, fabricating, repairing, and engineering.