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    • UnderDawg

      A Few Simple Rules   05/22/2017

      Sailing Anarchy is a very lightly moderated site. This is by design, to afford a more free atmosphere for discussion. There are plenty of sailing forums you can go to where swearing isn't allowed, confrontation is squelched and, and you can have a moderator finger-wag at you for your attitude. SA tries to avoid that and allow for more adult behavior without moderators editing your posts and whacking knuckles with rulers. We don't have a long list of published "thou shalt nots" either, and this is by design. Too many absolute rules paints us into too many corners. So check the Terms of Service - there IS language there about certain types of behavior that is not permitted. We interpret that lightly and permit a lot of latitude, but we DO reserve the right to take action when something is too extreme to tolerate (too racist, graphic, violent, misogynistic, etc.). Yes, that is subjective, but it allows us discretion. Avoiding a laundry list of rules allows for freedom; don't abuse it. However there ARE a few basic rules that will earn you a suspension, and apparently a brief refresher is in order. 1) Allegations of pedophilia - there is no tolerance for this. So if you make allegations, jokes, innuendo or suggestions about child molestation, child pornography, abuse or inappropriate behavior with minors etc. about someone on this board you will get a time out. This is pretty much automatic; this behavior can have real world effect and is not acceptable. Obviously the subject is not banned when discussion of it is apropos, e.g. talking about an item in the news for instance. But allegations or references directed at or about another poster is verboten. 2) Outing people - providing real world identifiable information about users on the forums who prefer to remain anonymous. Yes, some of us post with our real names - not a problem to use them. However many do NOT, and if you find out someone's name keep it to yourself, first or last. This also goes for other identifying information too - employer information etc. You don't need too many pieces of data to figure out who someone really is these days. Depending on severity you might get anything from a scolding to a suspension - so don't do it. I know it can be confusing sometimes for newcomers, as SA has been around almost twenty years and there are some people that throw their real names around and their current Display Name may not match the name they have out in the public. But if in doubt, you don't want to accidentally out some one so use caution, even if it's a personal friend of yours in real life. 3) Posting While Suspended - If you've earned a timeout (these are fairly rare and hard to get), please observe the suspension. If you create a new account (a "Sock Puppet") and return to the forums to post with it before your suspension is up you WILL get more time added to your original suspension and lose your Socks. This behavior may result a permanent ban, since it shows you have zero respect for the few rules we have and the moderating team that is tasked with supporting them. Check the Terms of Service you agreed to; they apply to the individual agreeing, not the account you created, so don't try to Sea Lawyer us if you get caught. Just don't do it. Those are the three that will almost certainly get you into some trouble. IF YOU SEE SOMEONE DO ONE OF THESE THINGS, please do the following: Refrain from quoting the offending text, it makes the thread cleanup a pain in the rear Press the Report button; it is by far the best way to notify Admins as we will get e-mails. Calling out for Admins in the middle of threads, sending us PM's, etc. - there is no guarantee we will get those in a timely fashion. There are multiple Moderators in multiple time zones around the world, and anyone one of us can handle the Report and all of us will be notified about it. But if you PM one Mod directly and he's off line, the problem will get dealt with much more slowly. Other behaviors that you might want to think twice before doing include: Intentionally disrupting threads and discussions repeatedly. Off topic/content free trolling in threads to disrupt dialog Stalking users around the forums with the intent to disrupt content and discussion Repeated posting of overly graphic or scatological porn content. There are plenty web sites for you to get your freak on, don't do it here. And a brief note to Newbies... No, we will not ban people or censor them for dropping F-bombs on you, using foul language, etc. so please don't report it when one of our members gives you a greeting you may find shocking. We do our best not to censor content here and playing swearword police is not in our job descriptions. Sailing Anarchy is more like a bar than a classroom, so handle it like you would meeting someone a little coarse - don't look for the teacher. Thanks.
    • B.J. Porter

      Moderation Team Change   06/16/2017

      After fifteen years of volunteer moderation at SA, I will no longer be part of the moderation team. The decision to step aside is mine, and has been some time in the works but we did not wish to announce it in advance for a number of reasons. It's been fun, but I need my time back for other purposes now. The Underdawg admin account will not be monitored until further notice, as I will be relinquishing control of it along with my administrative privileges. Zapata will continue on as a moderator, and any concerns or issues can be directed to that account or to the Editor until further notice. Anyone interested in helping moderate the forums should reach out to Scot by sending a PM to the Editor account. Please note that I am not leaving the community, I am merely stepping aside from Admin responsibilities and privileges on the site.

constantijn

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  1. here we go again....
  2. Doug lord, if you would go sailing, you would find out that half the stuff you post is BS....
  3. doug, try not to post so much BS. get out your rocking chair and go sail boats. this way you would get practical experiance and be able to seperate the marketing bs strories from real stuff (and save us from all the frustration...). on top of that you could even build up some credibility..... my 2c.
  4. wait, let me get my popcorn!
  5. reaching back and forth semi foiling (going nowhere) is something completely different the foiling around the race course! non of these boats in the light wind pics are going upwind, only reaching around
  6. sk 99 has a very high creep, similair to that of sk 75. The E modulus is higher the the other Dyneemas, which is nice, so low stretch. Although more then strong enough it will creep considerably when sized to breakload only. (do not go too thin) Please note that the creep is very temperature sensative. sailing in Auz summer will create creep problems, while in UK summers you are fine ;-)
  7. aramid is yellow, PBO is deeper gold/ orange in colour. is this the plastic covered stuff from navtec, or does it have a braided cover? if any fibre is visible, tape it up to prevent further UV damage. the strength loss is less then 12% (maybe if you produce it very bad) and water is not a problem for PBO (acid is)
  8. what is the brand? any pics
  9. if you dump the rig a lot, as suggested, the cap shroud angle becomes small, resulting in the mastcompression going through the roof (most likely resutling in a "bang" and an expensive black dust could)
  10. No, Dynex Dux is a brand of rope from Hampidjan. Hampidjan is an Icelandic company, very big in offshore ropes and netting. the DD is produced from SK 75, so not the best grade for this aplication (in my opinion) Again, for high performance boats stretch is a more important value/ property then break load.
  11. Hi Mike, You shroud will be more then strong enough, that will not be an issue (strength is not the limiting factor in most cases). The only thing I am trying to point out is that stretch is also a very important property when building rigging. the max (non dynamic) load on a multi hull will be when just flying a hull, while sitting in. my guestimate is, that this will be your body weight + boatweigth. If you keep the loads below 20% of the BL then creep will be less of an issue. You then will have saved weight compared to wire, be bigger in diameter and will have a bit more stretch. money wise it can be cheap, but is depends what work you can do yourself. However, for a high tech, light weight boat like an A cat, stretch is a very important property ,as stretch equals energy absorbed in elongating the rigging, instead of being transferred into speed. Keep in mind that we are discussing very small amounts. (but still a few boat lengths in a full leg) my 2c
  12. As mentioned before herewith a small write up. It compares different materials used in building of standing rigging, without going to much in detail about each materials up and downside: When you design rigging there are 2 parameters; - breakload - stretch breakload is understandable for everybody and quite easy to do/ match stretch is a bit different. the engineering value for rigging is EA (MN), where E stands for the E modulus and A for area or cross section. Unit is in Mega Newton When replacing steel rigging you can measure what you have, and look for an alternative. As steel is the standard, most often we build to these equivalents. - rod rigging is the standard on bigger boats (and has the least amount of stretch of the steel rigging), you can measure the diameter, calculate the cross section, multiply it with the E modulus of Steel, hussle with the zeros and out comes the EA in MN. - for wire it is a bit different as it is spiral wound and has about 30% of air within the strands. furthermore due to the air it will compress and extend when you load it up. This is called construction stretch. - dy form or compacted strand is in between the 2 above. basically it is wire which has been pushed through a dy, changing the shape of the individual strands from round to a compacted shape. due to this there is less air, so more steel for the same diameter and also less construction stretch. We have measured the real stretch of lengths of wire and dyform to get their real EAs, as the values available from various suppliers are often not correct! When you have the EA of the steel rigging it is easy to match in any other material (as long as you know the E modulus). does not mater if it is carbon, pbo, dyneema, polyester, shockcord or bamboo! Obviously if the E modulus goes down the A must come up to keep the end result the same. Herewith a comparisson of different E modulusses: Carbon 295 GPa Carbon (low grade extrusions) 240 GPa PBO (Zylon) 245 GPa Nitronic 50 (rod rigging) 190 GPa Dyneema (SK 90) 130 GPa Aramid (Kevlar 49 & Twaron 2200) 110 GPa Dyneema (SK 78) 110 GPa Dyneema (DM 20) 93 GPa Carbon laminates always have between 30 and 50% resin. Dry carbon is not relieable. Carbon with resin can be fragile and hard to store/ coil PBO needs a UV shielding. The thin sizes only come with a braided cover and no compression layer and environmental barrier like the bigger stuff. PBO loses breakload over time Dyneema has creep (all grades, though the amount varies!!) Aramid needs UV shielding A braided construction (rope) will always have construction stretch, which can be pulled out, but which returns after coiling. All UD dry fibre solution need some kind of cover to keep the fibres together. A few words about creep: this is something which is misunderstood by lots of people. Creep is elongation under load, but it does not shrink again after unloading (like pulling on chewing gum) Creep is a property of the molecule of the fibre and cannot be taken out, whatever you do. Most of the man made fibres have creep, the amount varies. Eg Aramid and PBO have so little creep that its already gone when the construction of the rigging is finished. Dyneema has the most creep of the discussed fibres (and it never stops). Depending on load (load as a percentage of the break load) the creep will vary. A higher percentage will result in more creep. The creep also depends on temperature. Construction stretch: All braided or twisted constructions have this. Compressing and pre tensioning can limit this (like in Dyform or heat threating dyneema rope). When the stay or rope is higher loaded then before it will compress / elongate further. Hope this helps ;-) Cheers, C.
  13. hi Bob, if it is SK 90, the EA will be around 0.6 MN, so you will have 30% more stretch then with dyform. If you would switch to 3,5mm or 4mm diameter the stretch could be similair as in 2,5mm dyform. you seem to mix up the properties creep, stretch and construction stretch. Stretch is elongation due to force. when unloaded it will return to its original length. Construction stretch is what you have in a braided construction. When the fibres are loaded, the will compress and try to straighten themselves. Rope manufacturers try to do this in their factory by pre tensioning and heating with steam. This helps, but will not be able to prevent the construction stretch from occuring. each time you store and coil your rigging, you will have to pull it out again. (as the rope will shrinks a bit due to coiling). when you load up a rope higher then before it will compress (and elongate further) Creep is non returning elongation under load. compare it to pulling on chewing gum. it does not shrink back after unloading. This is a property of polyethylene molecules (the stuff Dyneema is made of). Although rope manufacturers sometimes claim differently, there is NO way to take out creep in the production of the rope while SK 90 has relative low stretch and high breakload, it also has the most creep of all Dyneema fibres. You will see that after a day on the water in higher temps and a bit of breeze, that you will have lost rig tension. Cheers, C.
  14. Hi Bob, the stretch you are mentioning is construction stretch. Stretch under load is not something you will easily see, because your windward stays will just stay tight, but will elongate (which means less wind energy transferred into speed)(Which is probably so small you will not see it on your GPS, as a direct speed difference). I presume you have SK 78 for side rigging. When you calulate the EA for the 3mm dyneema shroud it is about 0.54 MN. 2,5 mm dyform has an EA of 0,82 MN. This will result in 35% more stretch in your dyneema shroud, for the same load, compared to your dyform shroud. You will have saved weight, but have lost stiffness.
  15. yes you can build rigging in dyneema, but no I do not think it is a good idea. self spliced rigging will have lots of construction stretch. on top of that most ropes will be dyneema, which develops creep when under tension. the creep in dyneema varies with temperature, load (as a percentage of the breakload of the rope) and type of dyneema used. If you want to limit the creep, you will need to go up in size quite considerably, resulting in thick, not so lite stays (but still lighter then steel wire) with more construction stretch. so yes it is possible to build rigging in Dyneema. It helps if you do not care if you have repeatable rigging settings. (or do not mind bigger diameter shrouds) preferably low load stays as forestays and capshrouds on A cat. For diamonds it will not be possible to get any repeatable rig tension. (especially if you sail in an area with temps higher then 25C) If anyone is interested I can do a more elaborate piece about (composite)rigging Cheers, C.