alloy strengths is all different all over the world! our british ones are flexible but bend easily and always need re-straightening. where polish ones are very stiff and strong (according to rooster) so i might buy one if they still have some in!
James, better get it from Australia. A German racer just got 2 from there and know sells (or has sold) his nearly new ones from Europe - why? Maybe, the Australian ones are the stiffest/best, I guess.
Making "a" selfmade mast is not interesting for me, I get original used masts here in good condition and not to much more expensive, than a selfmade new one. And: selfmade ones are of course not classlegal!!
Not different is the situation for a boom. For training or temporay replacement (or if I would not get a used original one) I would make one from the material of a merchandizer for spi-booms (f.e. Pfeiffer Marine, Germany. Maybe you can get there material also for the upper mast section). Its much less expensive than the original (new) ones. But I have not the solution for getting the inner sleeve into this replacement-boom and: of course a selfmade-replacement boom is also not class legal.
But, I´m a non racer - what should me interest the Laserclassrules.... haha ;-)
At least I remember to my words at another, older thread:
If in nearer or farer future our Laser get´s its carbon masts to be cometitive again to the Byte CII. Then all the racers must get this new stuff and I will get really cheap as much from old alu-mastes/-booms as I would need for the rest of my Laserite-live, haha
I want to make a mast because I'm cheap! A lower mast costs about $225. I think I can get a bare piece of aluminum for about $50.
There are lots of aluminum alloys but only a few that are appropriate for extrusion and even fewer that are typically used in sailboat spars. I'm guessing that 6061-T6 is the one but 6063-T5 is a possibility, too. Anyone know for sure? I won't be racing this boat so I don't care if it is legal or even optimal. It would be nice if it didn't break, though!
The dimensions of the lower mast are pretty standard: 2.5" diameter,1/8" wall thickness, 112.125" length. This is a standard extrusion so I'm gonig to guess that they used a standard alloy, too - 6061-T6 is ubiquitous. (BTW: The radial rig is not standard: 2.4" diameter, 1/16" (!) wall thickness, 88 11/16" length - my guess it that this is a Vanguard custom extrusion.)
I'm pretty sure that tempering is a steel thing so I don't need to worry about that. Anodization only affects corrosion resistance. Since I will be sailing in fresh water I'll just put on some wax and forget about it.
Well i have heard that this has been done but for a laser 4.7 bottom section! (very hard to do when you think about the bend!) amazingly illegal so i recommend not making your own mast as if you read the laser hand book you can be banned from sailing a laser all together. the laser sections are very sheap so just buy one cheap and easy and its going to be legal if you want to race your boat in any laser association events in fact any regatta's as in the race instructions so yeh i recommend just buying it mate save you the hassel and keep the class going strong and within the one design rule.
I sailed with a home made top section for about a year. I found a metal yard that sold 6061-T6 tubing, they had the right size tubing, but it had thicker walls than the standard Laser top sections. As a result of the walls being thicker it was less flexible and a tad heavier.
It was actually alright to sail with, I couldn't really notice any lack in performance, and my usual positioning in races stayed the same. If you manage to find the tubing with the correct wall thickness it would be perfect. The only reason I don't use it anymore is because somebody with a Micron (Mini Laser) offered to buy it off of me, apparently it's identical to their bottom sections.
...I'm pretty sure that tempering is a steel thing so I don't need to worry about that. Anodization only affects corrosion resistance. Since I will be sailing in fresh water I'll just put on some wax and forget about it.
Actually, aluminum is annealed, hardended, and tempered very much the same as steel. The "T6" tells the particular kind of treatment the metal got after it was formed (in the T6 case, a complex heat and chemical treatment).
Annodizing isn't only for corrosion resistance. It also imparts some strength to the item (some high-performance Aluminum masts are annodized on the inside for this reason).
In you case, probably neither is terribly critical. You won't be doing anything to the extrusion to change the temper it has from the supplier, and the lack of annodizing probably won't affect the section much.
the sentence in Reply No. #8 Tom is quoting from the official Laser-Handbook for ILCA members (2004 Page 24) is dedicated to all the people, that do Laser-racing with wilful setting them selves the goal, to win with illegal methods of tuning their boat (cheating).
I sure believe, this was not the intention Tim had, by asking for making a selfmade-mast.
But an important point to notice to the selfmade-stuff is:
If you make an accident with that selfmade-stuff (that is not class-legal) and this stuff is the reason (more or less) for the accident, then you maybe have a big problem, with your insurance or the lawyers of them, you maybe unfortunately have hurt. I´m not quite sure about this aspect.