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Broken luff track?

Posted: Mon Jan 21, 2013 8:06 pm
by paul manning
Rick and I were talking about this today and he came up with a possible good idea.

What about a strop of Progrip stuck to the luff track where the batten ends are?

It would be easy to hoist the sail and then mark each batten for max. on and fully off...

Just a thought :!:

Re: Broken luff track?

Posted: Mon Jan 21, 2013 8:23 pm
by Rick
Thats a STRIP of progrip :D a strop is what you have if the track brakes :x

We thought that the soft "cushion" between the track and the batten end pocket protector would reduce the point loading on the track.

A strip about 150 x 20mm on each side ... stuck on the track.

Probably only needed on the bottom 3 batten locations.

Anyone suffered with this going to give it a try?

Re: Broken luff track?

Posted: Mon Jan 21, 2013 10:07 pm
by paul manning
You are right, but it might stop a strop...

Re: Broken luff track?

Posted: Mon Jan 21, 2013 11:14 pm
by Serega
a strip of progrip
to stop a track strop

Re: Broken luff track?

Posted: Tue Jan 22, 2013 9:48 am
by Rick
Serega wrote:a strip of progrip
to stop a track strop


Yep, try it :D

Re: Broken luff track?

Posted: Tue Jan 22, 2013 2:52 pm
by RUS213
Both my masts suffered this damage - cracked sail-track in the region of lower button. One mast was repaired, but other is still un-repaired since my friend (specialist in all repairs) broke his shoulder and still under treatment. But, frankly speaking, I didn't understand anything :-). Perhaps, I need to see the sketch or picture to understand. Otherwise, it is too difficult even to quickly pronounce: strip-track-strop-stop-progrip ...

Re: Broken luff track?

Posted: Tue Jan 22, 2013 3:33 pm
by Rick
Progrip is a thick but flexible self adhesive rubbery material.

See http://www.sailboats.co.uk/Product~ProG ... 76915.html

The suggestion is to cut a strip about 150mm x 20mm and stick it on the mast track at the point where the batten pocket hits ...

Re: Broken luff track?

Posted: Tue Jan 22, 2013 5:16 pm
by Besty
not sure i understand this...

if progrip on inside of track then it would stick to luff when hoisting making this a nightmare.

if stuck on the outside there would still be direct contact between the batten end sockets and the mast track

???

Re: Broken luff track?

Posted: Tue Jan 22, 2013 8:05 pm
by Rick
Put it on the outside of the track so you have a thin cushion between the batten end pocket and the mast track. Thus removing the point loading.

Re: Broken luff track?

Posted: Tue Jan 22, 2013 9:13 pm
by RUS213
Can we address this issue to the mast/sailtrack manufacturer ? If they have feedback from sailors about this problem, may be they will strengthen some problematic places somehow ? I mean for the new masts, for future ...

Re: Broken luff track?

Posted: Tue Jan 22, 2013 9:23 pm
by Rick
Paul and I have discussed this with Selden a number of times and they state that the material they use is the best they can source. It has to be stiff enough to retain the bolt rope but also flexible.

But the failures are a right pain to fix.

Fun off Freo

Posted: Tue Jan 22, 2013 9:28 pm
by paul manning
Thor

Just for the record, did you see the post about Progrip on the mast?

Tim Hill mentioned the track damage (which is something we've had, but have not yet resolved)

I think it would be worth trying, as it seems to be caused by sudden impact of the batten ends against the track. The likely hood of damage seems to increase as the batten tensions are increased, so we thought this might work as an impact softener.

Re: Broken luff track?

Posted: Tue Jan 22, 2013 9:34 pm
by paul manning
The problem has increased as the class has straightened the mast and increased batten tensions. The sudden impact can be too high for the plastic track and we are trying to think of a way to reduce the shock.
As Rick says, we hope the Progrip will act as a cushion between the two materials.

Re: Broken luff track?

Posted: Tue Jan 22, 2013 9:40 pm
by Rick
Note that I think some people are applying far too much batten tension.

Re: Fun off Freo

Posted: Wed Jan 23, 2013 12:39 am
by Thor
paul manning wrote:Thor

Just for the record, did you see the post about Progrip on the mast?

Tim Hill mentioned the track damage (which is something we've had, but have not yet resolved)

I think it would be worth trying, as it seems to be caused by sudden impact of the batten ends against the track. The likely hood of damage seems to increase as the batten tensions are increased, so we thought this might work as an impact softener.



Hi Paul,

Yes I saw that post earlier and was intrigued.

In the 12mths I have been sailing I have only broken track one (last time I sailed which was last day of the AUS nationals). I am yet to drop my rig and have a closer look but I have seen Mark fixing his a number of times. I agree it’s related to batten tension but I am not sure exactly how the pro grip will go towards fixing the problem. My humble opinion is that it’s breaking due to the excessive sideways force on the track. And I believe is not necessarily due to the point loading from the batten end causing the fracture. I would have thought that the bolt rope would have reduced the point loading somewhat significantly. My thoughts are that seeing as its breaking the track out sideways (the only form of failure I have seen) is that its due to a combination of the main being let out completely until it touches the shrouds such that the main inverts with the boom all the way out. Use of cunningham while the main is like this will only exacerbate the problem. I have thought that a solution to this would be strengthening the track in way of the batten pockets. I had an idea to glue a small strip of rectangular/box (say 5mm x 3mm or there abouts) carbon/plastic along the outside of the track right near where the sail enters the track such that it’s on its end (the 3mm part of the rectangular section is glued to the track). You could round the ends off and sand it down such that its nice and smooth and un obtrusive. The reinforcements would have to extend 150-200mm above and below the mean batten position and taper down such that there is support where its required and the end points of the reinforcement don’t create another hard point.
I bought the boat off Tim Hill last Jan and have not touched the batten tension in the main(s) at all. I have always thought that the top two battens in the old main (which is now completely shagged and the only main I used up until the nationals just gone) were a little loose but never bothered to fix it. This may be one of the reasons I have been lucky to have only just broken my first bit of track. This top section is only 2mths old so UV damage to the track making it brittle could almost be excluded as a contributing factor.

Anyway…. That’s just my thoughts on the matter as opposed to upgrading the track to a thicker wall/ carbon/ali section/ new mast profile with inbuilt track solution.

Unless I missed how you were saying to apply it I would have thought that the progrip would have just peeled off when hoisting and lowering the main? I find there is enough friction there to warrant McLube.