Spindrift 10N - mast size - aluminum 6063 T5

[bassoan]

Graham,

I

[ricardo]

First try was to make an hollow wooden mast. Birdsmouth, Parana Pine. The thing was beautiful but quite heavy and cracked in a poorly made glue joint.

Then I went to an aeronautical junkyard in Campinas, and was lucky enough to find the right tube to the lower section. Middle section is not T-6 and upper section is wooden. Worked fine 'till now.

If you

[wardm]

Hi Andre

I am not sure if you saw these threads. I had trouble with a weak tube section on my S10 as I could not get 6061 either, you can see the pictures of what happened at the bottom of this thread. I could not get 6061 T6, but am now using 6063 T6 with a stiffener in the bottom section. So far so good 

http://www.messing-about.com/forums/index.php?topic=5760.0

There is also some good information on this thread.

http://www.messing-about.com/forums/index.php?topic=2015.0

Some of the interesting points from postings on this thread

- The two alloys are fairly comparable.  6061 is optimized for strength, where 6063 is optimized for corrosion resistance and formability.  The yield strengths are like 40,000 psi vs. 32,000 psi.

- The 2 1/4" od x.065" wall 6061 T6 is just strong enough for your boat. As 6063 probably T5 is a lot weaker, then your only option is to use the heavier 2" id x 3mm wall if you can't get the right stuff. For the next section you can get whatever will fit inside the lower section and you can make a wood top piece.

Wikipedia also has information to explain the difference between the two alloys and the different tempers

http://en.wikipedia.org/wiki/6061_aluminum

http://en.wikipedia.org/wiki/6063_aluminum

Rgds

Mark

[bassoan]

Ricardo,

I guess I won't find anything around R$ 100 (cost of Al tubes) at the sailing clubs. But it is a good option that I

[wardm]

Andre

You could try http://www.onlinemetals.com. shipping might be expensive though.

I think a Laser sailing dinghy mast top section and boom match the required dimensions and are also 6061 T6, if you could find

an old section lying around it might do the job for the bottom half of the S10 mast.

I had a lot of old sailboard mast sections lying around from my windsurfing days, but they were all a little shorter than the S10 required mast length, so I used a Fibrespar carbon sailboard mast top section and alloy tube bottom section for my S10.

Good luck

Mark

[Garry]

My question to Graham remains. The dimensions given on the second thread are for the S11. I was wondering if I could use something lighter for the S10.

Andre,

If you have a specific question for Graham, it's best to email him directly. He's good about responding to email but there is no guarantee that he will read every post on the board.

Garry