For those who are dreaming about building an F16 in a remote corner of the world and have trouble finding masts. This thread in the builders forum could be worth to watch.

http://www.catsailor.com/forums/sho...4&an=0&page=0#Post134804


We are using cut down Tornado masts which we will move the fittings on to suit the F16 sailplan on our boats. But if it is possible to build a wood mast at the same weight as an alu mast, it opens some very interesting opportunities.

Yea, I think we should change the rules to make wood mandatory. Oh, don’t forget the bamboo sails because we can’t leave out that technological leap.

Hey, dont knock wood <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Yeah

Timber - epoxy hulls here mate and still going strong !

Wouter

wood is so 1930s.
Haven't you heard that most big manufacturers use 400lbs of epoxy these days? It is the "new" thing. wood would keep things too light <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Bamboo is being used for flooring, socks, blouses and who knows what else. Why not hulls, sails and masts! <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />

Talking about masts, the same could be applied to beams I think.
I remember paying about US$300 for two alu beams for a 16 foot cat 7-8 years ago. For that price I could build composite beams instead. Just need some engineering done first, any volunteers <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

Hi Rolf,

have a look at http://shop.ezentrum.de/2461261/sTVeLqG5...amp;artid=71646

It is in German, but it is a CFRP tube for about 150mm diameter and 5m length, or not other crossections with same perimeter. It gives you a nice +-45 basis (which shoud be topped by some UD cloths). It is certainly not the cheapest shop, but it gives you an idea (it is certified for aircraft structures). Correctly done you dont need a dolphin striker = less nasty drilling in CFRP. Regarding engineering: Well I cannot give you full engineering support (but do you relly need it?), but some stress calculations, sizing and so on. But not within the next two weeks. Just let me know.

Cheers,

Klaus

Even better, I know a hippie that can grow some hydroponic bamboo. It will be so strong NASA will be calling you.

Aren't the re-entry shields on the Chinese space capsules made of balsa? Don't knock wood.

Sign me up for that re-entry...NOT!

How do you like your Chinese; rare, medium or well done?

Actually the "re entry" surface "tiles" used by the old USSR on all their personnel carrying orbital vehicles was/is wood. It is only used once then completely replaced and is very effective and cheap (apart from being non reusable). The first shuttle for the USA was for some time before it's completion also going to use wooded tiles until they came up with a much more expensive but reusable "tile" system. It has been said that if NASA had/did use wooden tiles there would be a few astronauts that perished still alive today.
(The tiles are, I believe "cork" so "Corksfloat" is very appropriate?)

<img src="http://www.catsailor.com/forums/images/graemlins/smirk.gif" alt="" />
In real world it is some combination of phenolformaldehyde fibre and resin. No wood hard enough in our forests.

Actually, the use of wood and situations of heat/fire is actually largely misunderstood by the main populace. What else is new here ?

For example, Firefighter prefer buildings with timber trusses over steel ones. The reason being simple. It will take a very long time for a thick timber truss to burn through enough to fail. Steel and aluminium versions can weaken and bend or fail within minutes.

This effect is caused by the fact that wood chars up on the outside isolating the untounched timber on the inside and the fact that timber is largely insensitive to heat and conducts heat very badly.

Basically the core of the thick truss remains largely unaffected for long times of directed heat influx.

Metals conduct heat very well and will soften up quickly when heated up. As soon as they have heated up they will deform, bend and break bringing down the roof or walls.

The fact that Timber trusses need to be much thicker then the steel variants in order to carry the same loads actually increases this difference in behaviour favouring the timber trusses even more from the perspective of maintaining integraty under fire.

Someone said to me several years ago. "If wood was discovered today then it would mean a revolution in material use."

And it is indeed a largely misunderstood material.

Wouter

there you go

if you home build your mast out of over sized section wood , you keep it in your garage over the winter which catches fire , you can be happy in the knowledge it won't bend or melt bopping the fire peeps on their heads <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

I prefer my mast made of carbon from wood compressed over millions of years(or wherever the carbon comes from ) and knitted into a new shiney stick, which I expect would burn like it was going out of fashion (the epoxy that is ) .after the fire reknitt the carbon and remould again .

When I was at JP's place it was amazing to see the rolls of prepreg carbon in his freezer which can quickly be transformed into a lightweight mast ,

anyone want an alluminium saarberg A class mast still like new ! , unfortunately the West Epoxied A class hulls burnt rather well after a hard life !

Now that is what I call forward planning! <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />
With all the ridicule, I really hope Gato pulls something good off <img src="http://www.catsailor.com/forums/images/graemlins/laugh.gif" alt="" />

I read here some while ago somebody said he used less epoxy to save the environment. If somebody is caring about the environment then have a look at the process of producing carbon fibre, it’s absolutely eating energy...
http://pslc.ws/macrog/carfsyn.htm
It’s not the same thing that the carbon the blacksmith use in his forge...
<img src="http://www.catsailor.com/forums/images/graemlins/smirk.gif" alt="" />

Unless you have a huge amount of hydroelectric power available. Loss during transfer of electricity is a problem, so runnin a carbon fiber production plant close to a hydroelectric dam makes sense. The same thing is done with aluminium plants here in Norway.
Only problem is that they are building lots of new transfer lines to export electricity now, as the price abroad is so high that it justifies the loss during transfer (which again raises prices for electricity here in Norway, both for the industry and regular people)..

There is a small flaw in your soup Rolf. Even close from a hydroelectrical plant it’s not wise to produce carbon or alu. in execs. The energy could be used for something more useful and the price kept low...

With respect to aluminium this only applied for produce NEW aluminium from its ore (Bauxiet).

Recycled aluminium is MUCH less energy intensive. Interestingly enough recycled aluminium is practically undistinguishable from new aluminium even after having gone through many cycles.

That is why recycling aluminium (soda cans) is such a wide spread activity.

I keep saying it. Aluminium is a pretty wonderful material. Only it low 0.2% yield stress limit is somewhat of a party pooper.

Wouter