Discussion in 'Laser Class Politics' started by mattsterett, Jan 20, 2004.
Laser one-design! Gotta love the concept!
I still have; and use all the original spars for one of my full-rig 1974 lasers...They probly have over 1500 hours on them now, and I've never bent any of them, except the boom, which I managed to bend back into shape.
In my area, we have gusts of 25+ knots about 3-4 days a week, so I'd have to say that the older masts were made of stonger material, no doubt about it...
The manufacturers are opting towards using cheaper material now, which seems to be causing some problems with reliability. A few training partners of mine are having very bad trouble with their spars, one of which managed to snap their upper section just above the joint, on a day where the highest recorded gust was only 21 knots...
Manufacturors definelty need to start using better quality materials.....
They defiantly do need to, I have never bent my old spars, and as far as I know they're as old as the boat (1980s). In fact all of the old lasers down at my club seem to be indestructible, it's all of the new lasers that are going in for repairs, or maby the sailors care more for the newer boats.
Yes indeed! And on a closely related subject, why the difference in spars and fittings depending on origin? Aus spars are stiffer, and the collars are a tighter fit into the bottom section. The UK spars are softer, at least in my experience. I've sailed with both, a lot. Old and new. Interested to know if either lot break more or less.
The last I heard was the current Australian bottom sections are coming from the UK.
UK ones come from Poland.
I've a top mast from a boat around 100000 number (guy did look at me funny when i asked about it) but it is the best one i have. Higher and faster! Best one ever was an oz one which weighed 3.2kg.
Nothing like a one design class then.....
Apparently (I am sure some of the metallurgists here will blow this down) but if you buy a new top section to stiffen it up you should leave it outside (under your boat) for a couple of years. The theory is that the anodising gets thicker and makes the whole tube stiffer. Personally I am not convinced but this may be 1 reason why the older spars stay straighter than the new ones.....
I thought I'd already blown that one out, maybe not. No change will occur with the anodized layer other than it potentially getting damaged and breaking down as a result. The anodizing process occurs at quite high currents and then the oxide (sic) layer is soaked in boaling water to cause it to swell, filling the voids of the honeycomb structure. The more usual they is the spars will age harden if left outside for a few years. Whilst aluminium alloys will age harden, the alloy used for spars which is either 6061 or 6063, requires temperatures in the order of 150-200 deg.C to age harden.
The older spars were likely to have been a different alloy, probably had a different heat treatment and were probably thicker walled. The alloy used probably hasn't been produced in 30 years in bulk.
I still can't understand why the radiual sail wasn't cut to match a cut down version of the standard rig bottom section, instead of going to a thinner walled tube with a sleeve.
I remember you answered a threat on work hardening but I cannot remember if that covered age hardening or not. Thanks for the clarification.
As for the radial they did try a shorter top section for the M rig but found the mast was just too stiff IIRC. This lead to the birth of the radial. I also recall the M rig mast length overall is practically the same as the radial mast length (I do stand to be corrected on that though).
The M rig had a full size mast and luft pocket, but the effective head of the sail was part way down the mast from memory.
If you remember the dislocation movement in the work hardening thread, instead blockages caused by dislocations meeting each other, there are precipitates in the grain structure that block the dislocation movement. The aging process involves the growing of these precipitates, usually at elevated temperatures for extended times. There size impacts on how effective the blockages are, too small and they are easily bypassed, to big and the dislocation can move through them.
I didn't pick the old top mast for the age of it but for the construction. You can tell depending on what sail you put on it. North sail has about 2mm extra luff curve and fits better to modern masts where as the Hyde is suited to a stiffer rig. Hyde with a stiff rig is best but a north with a bendy rig is still better then a hyde with a bendy mast.
But is a North with a stiff rig better than a Hyde with a bendy rig? And is an Intensity with a stiff rig better than a North with a bendy rig, or is the Intensity with a bendy rig even better than a Hyde with a stiff rig?
I love this one design sailing.
No idea about copy sails but north with a stiff rig is only a problem over 25knots (bit over powered) but a hyde on a bendy rig is fighting for power and hight under 18 knots. The lack of luff curve causes luff curve starvation. This is the extreme of masts and no two bend the same ( as we all know ) so it just depend on what you can get hold of.
i know its a old thread but are Australian spars still superior? my radial bottom has a crack and is about to snap. if they are superior and last longer would it be worth it trying to get one in the us? thanks
They don't have a US distribution network and probably won't ship to a US address.
The last time I heard, PSA was sourcing their radial bottom sections from LPE, because what they could source from or region were far inferior to what LPE supplied, i.e you looked at them and they would bend. Having said that, the Radial bottom sections here still bend with amazing ease.
The UK Radial bottom sections are very prone to bending. Sailorchick who posts on here mentioned in another thread she goes through them on a regular basis!
Was at the Stokes Bay Q talking to lots of other radial sailors last weekend, its not just me. Consensus there was you were lucky to get more than one weekends sailing before a bottom section bent (this is folks who are finishing in the top 10 at the qualifiers). There were a couple of fine examples of very bent bottom sections in the boat park!
All the sections are made by seldon to the same specifications.. rumors about spars from different locations having different durability is bs.
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