Mast section.

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trebor
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Mast section.

Post by trebor » Sat Mar 29, 2014 7:56 pm

I have bent bottom section of my Mast today, quite badly, whilst being rescued from an inversion,(curse of the safety boat).
Would it be better to replace like for like, or a slightly thicker section?
The Mast is a 2 part sectional Mast, top half is buoyant, bottom section is 50mm diameter, their are only 4 holes drilled in it, 2 are at top with pop rivets to prevent top section from going down to far, the other 2 hold bracket for small block, the mast material is approx 0.3mm thick and very flexible.
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Re: Mast section.

Post by JimC » Sat Mar 29, 2014 11:01 pm

trebor wrote:Would it be better to replace like for like, or a slightly thicker section?
Likr fpr like would be my choice, better too bendy a mast than too stiff, but how on earth you specify it I don't know... The question is whether it was ordinary stock anodised tube or heat treated for extra stiffness as almost all spar material is. I imagine it would be the heat treated stuff, but who knows...

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trebor
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Re: Mast section.

Post by trebor » Sat Mar 29, 2014 11:39 pm

I have posted the video that led up to this inversion, warts and all, comments on a postcard :D
Their is a seller on ebay who specifies his tubes are spar material, £9.00 per metre.http://youtu.be/10TUATCFHGk
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Nessa
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Re: Mast section.

Post by Nessa » Sun Mar 30, 2014 7:49 pm

From what we can see you needed a lot more out haul to flatten that sail and get it under control. More kicker on the upwind leg for the same reason. You need to look around more so the gusts don't catch you out.

The most striking thing though, is how uncomfortable you look. You are so scrunched up you are always steering behind you so can't react to what the boat is doing until it's too late. You can't really see up into the sail, and it's tricky to really look around. You can't use body movements to steer the boat, so you're resorting to being over firm with the tiller.

Realistically you need a bigger boat so you can sit in it more efficiently, or a bigger, stiffer sail that will give more power. I would be favouring the bigger boat if I were you.
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Re: Mast section.

Post by Rupert » Sun Mar 30, 2014 8:10 pm

There are certainly techniques for being more comfortable on a sailing surfboard - at some point we shall have to have a get together again Rob to take a look at that.

I couldn't see as much from the video as Nessa has, but would certainly agree about the outhaul.

As for the mast section, go for what is available, and if you think it is too bendy, you can always sleeve the mast at the bottom by putting a slightly smaller tube inside.
Rupert

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Re: Mast section.

Post by jpa_wfsc » Sun Mar 30, 2014 8:29 pm

It can be very frustrating stalling every time you tack.. with most single handed single sail boats (and to be honest, most others also) the improvement in fun once you know how to roll tack are immense!.

I can highly recomend the Rooster 'Boat Whisperer' videos - there are some on Youtube but the best bet is to buy the DVD from Rooster. Yes - its all Las**r sailing but the techniques will apply perfectly to your Aquabat. The one on Gybing will be of particular interest just now.

And also - I'm sure - that once you have got the aquabat powered up and you can hike you will find its big enough.

As for the tube - yes - go for the orriginal section - if the bottom is very much stiffer than the top, it may cause sail shape control problems.
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Re: Mast section.

Post by phil58490 » Sun Mar 30, 2014 8:55 pm

When you are 'in irons', remember 'push and push'.

That means push the boom out and push the tiller away from you and it will come round and you will be on the correct side to sail away.
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Re: Mast section.

Post by trebor » Sun Mar 30, 2014 9:04 pm

Hi all, above comments all correct, in my defence or perhaps not, I have Flu and should probably not have been out (probably definitely).
I had forgotten completely Outhaul, Sail was a big bag. :oops:
The start was in Hellfire corner, this is a 90 degree corner of pool and wind gets trapped here, I was proppelling like mad to get out of irons, the wind and gusts were virtually coming from both sides, wind was 16 mph with gusts to force 5, all excuses I know, however I was not the only one stuck here and actually came through start in 4th place and kept this to number 1 buoy, this is the longest leg on pool and upwind all way, I then turned to "reach" to number 7, this is where Gybe and gust threw me over.
(I have not put rest of video on, it does not look good for quality of safety boat cover.)
Instructors who wish to use this video for guidance on how not to do it, are more than welcome :D
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Re: Mast section.

Post by Spiderman » Tue Apr 01, 2014 8:33 pm

Hi Robert,

Having now watched all of the video there are a few points that I would like to add to the comments already made.
Firstly, as has been mentioned, the outhaul was far too loose which would be one of the main reasons for your difficulties upwind and would certainly have contributed to the frequency of failed tacks and getting stuck in irons. More kicker would bend the mast and flatten the sail, but with the outhaul so loose would have increased the leech tension and made getting out of irons even harder. The push and push technique that has been suggested works up to a point, but a tried and tested Laser method of getting out of irons is cunningham on hard, kicker eased and daggerboard raised at least half way. This will result in the nose of the boat paying off one way or the other and doesn't require any of those vigorous tiller movements. Once the boat is below a close hauled course onto a beam or close reach keep the boat flat and sheet in till the boat starts to accelerate and regains steering control. Only then should you put the board back down and pull the kicker back on. If you watch a crowded Laser start in a bit of breeze when they all tend to rack up a couplke of lengths below the line you will see the odd person using a variation of this to avoid getting into irons and ending up stationary on port tack just before the gun!
Replacing the two shackles holding the bottom kicker block to the mast with a swivel will allow the cleat block to turn towards you when you pull the rope giving you much better control of the kicker tension from either side of the boat.
I don't know if you already have a wind indicator attached to the mast, but it appeared to me that you weren't always totally aware of the wind direction in relation to the boat and sail. For example, you had the sail in to far on the downwind leg which is one of the reasons you capsised on the gybe. It looked as though the mainsheet wasn't running freely enough through the blocks to help ease the sail on the bear away which may help explain why you were oversheeted at times.
I think that an "on the water session" with Rupert would definitely be of benefit and help you improve your technique, especially the tacking and gybing so take him up on his kind offer!
Finally, don't be disheartened as we have all been there at some point and it takes time on the water and sometimes a bit of help to overcome some of the obstacles to progress.
I though you looked pretty cool donning your shades on the way down to the start if that 's any consolation.

Regards

Ian

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trebor
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Re: Mast section.

Post by trebor » Tue Apr 01, 2014 10:14 pm

Hi Ian, thanks for comments, I also play golf and I know how bad habits can creep into your game that can only be seen by someone else, same with sailing.
A few more facts to go with video.
The Aquabat deck is same size and shape as a Laser, the cockpit is also same depth, but with benched sides for comfort.
The sail is 80 square feet.
The boom is over 10 feet long and sticks past the transom by about 16".
Their is some distortion in video, either depth of field or digital, I may look like the Michellin man, but I am 5 feet 9" and weigh 10 stone.
Their is a wind indicator on mast, it is just out of shot.
The section of video where I am beating up to buoy 1, you can see me being chased by several boats, the only one that gets close is the Comet, he nearly takes out the Laser in his attempts to catch me, if you then follow video to where I go round Buoy 1, you will see that I have left him for dust and all the other chasing boats, the Aquabat points really well.
I have found with the Kicker that if I set it for reaching, I can pull boom down with the main sheet for beating and not have to adjust kicker ( I may be wrong on this ?).
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Re: Mast section.

Post by Rupert » Wed Apr 02, 2014 8:49 am

Using the main, not the kicker, works in weather where you are looking for power, not spilling wind. As soon as the wind is at a point where you need to spill, then the kicker has to be tight, or the boom rises as you let the main out, and your sail powers up instead of spilling wind. Even in the ligher breeze you may well need a tighter kicker on the beat than on a reach, too - you just want the boom to rise in the lulls (when you free the sail a little to "let it breathe") enough to create some sail shape, not to have it lose all shape.

Rob, are you coming to the Minisail Nationals and training? It sounds like your sailing has come on a lot since last time you were at Whitefriars, but is in need of some input from outside - I suspect the people you are racing against are also setting their boats up wrong, and making some errors. You can only race those put in front of you, but watch out for picking up their bad habits!
Rupert

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Re: Mast section.

Post by trebor » Wed Apr 02, 2014 5:42 pm

Hi Rupert, I will be attending Nationals, but will probably have to bring Aquabat, (I would also be interested in the autumn training that was mentioned in another topic).
I have realised that you need to mix up your sailing, that is why last year, I approached Greensforge to set up an inter-club racing league.
re- Main sheet, the mainsheet on boat at the moment is my "winter main" it is 16mm diameter, ( but it is easier to grip with numb fingers), their is also a jamming cleat, I use this continuously, plus following advice from Rupert some time ago, I allowed enough mainsheet to let boom go slightly forward of mast when running, this means their can be a lot of slack in cockpit, sometimes you have your foot on it.
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Re: Mast section.

Post by Rupert » Wed Apr 02, 2014 8:55 pm

16mm!

I had a 10mm mainsheet on the Lightning for a while when my grip was poor, and that was too big. 8mm would be about right - it would explain the mainsheet not running freely.

I get tangled in the mainsheet, too. When sailing the Firefly with Kathryn, she always sorts it out for me. Singlehanded, I find nice ankle wraps at just the wrong moment.
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Re: Mast section.

Post by fcdbm » Wed Apr 02, 2014 9:04 pm

Returning to mast tube enquiry....

Laser topmast section is 50mm outside diameter, 2mm wall thickness.

As these regularly bend and snap most Laser sailors will have some broken section lying around. Approx 3m length (broken)

Alternatively checkout Needlespar at http://www.hawkmarineproducts.com/needle.htm

Good luck.

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Re: Mast section.

Post by trebor » Wed Apr 02, 2014 10:28 pm

Hi Rupert, I think it may be 12mm, not sure now, definitely thicker than 10mm though.
Hi fcdbm, The bottom section of mast is longer than 3 metres, it is also incredibly thin, a lot less than 3mm, in fact less than 1mm, the top section is 43mm diameter, however I do not know what thickness it is, it is plugged both ends to make it buoyant, I have also increased length of mast overall by 4", mainly to increase clearance under boom, the extension was attached to top section of mast.
I would probably need to increase Kicker to the "Laser cascade kicker" to bend a 3mm section ?
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