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Re: Broken luff track?

Posted: Tue Jun 17, 2014 9:27 am
by Rick
John,

Much better to raise the issue than suffer in silence; we want this issue solved.

Have you read this page?

http://www.mustoskiff.com/sub-pages/selden-mast-updates.htm

Note:

Selden's supplier has modified his tooling to ensure that the extruded polymer will always have web walls nearer to the thicker end of the Selden drawing tolerances. We believe this will provide us with a product that’s less susceptible to web distortion coupled with thicker web walls will hence be generally tougher. The specification of the plastic used will also be adjusted to make the track less brittle.

Unless you are doing the repair with the latest track from Selden it is likely you will continue to have problems ...

I would request Selden send you another kit via a tracked courier and make your repair with that; then you have the latest specification track.

Re: Broken luff track?

Posted: Tue Jun 17, 2014 11:19 am
by Bruce
Hi John,

If it is breaking that often then you either have a really poor quality piece of track or there is something wrong with your boat setup. I would suggest replacing ALL the track and then seeing what happens. If it continues to break, then it must be something to do with how you setup/sail your boat. Batten tension would be the most likely culprit. I don't recall ever breaking mast track on a Musto (yet!), so if you have a decent piece of track and good setup then you shouldn't have a problem for years.

Re: Broken luff track?

Posted: Tue Jun 17, 2014 1:56 pm
by John Archer
Hi Rick, Bruce,

yup I've read-up on the whole saga :-)
There's not a date on the page, my boat was delivered in 2012 and the track used for repairs was given to me by Ovi's in Weymouth, as far as i know it is the right spec material. If i receive the repair kit from Selden then I can be sure it's the right spec.

As for battens yes they seem likely candidates, I had a lot of tension on previously but backed it off after Weymouth plus made sure to release the cunningham downwind (something I didn't get around to in a few races). After lasting more than a season I thought it was problem solved.
I wonder if it's differences in sail build vs. mast build or track specs that dictate issues or not, position of plastic batten pocket ends?

I'd be happy to experiment replacing the entire track but reticent to bear the cost vs. small repairs every couple of years.
Also not sure it would tell us much unless no failures experienced after up to say 4yrs, presumably we need a test rig to go through thousands of cycles to draw data-based conclusions, Iver would describe better!

Constructive next step: build fleet database of number of track breakages, position on rig (relative to battens), conditions when broke.
Thoughts?

Rgds,

John

Re: Broken luff track?

Posted: Tue Jun 17, 2014 2:45 pm
by Rick
John Archer wrote:as far as i know it is the right spec material. If i receive the repair kit from Selden then I can be sure it's the right spec.



That update was from earlier this year; so I'd recommend getting a kit delivered from Selden and going from there ...

Whilst there have been a number of these failures over the years it is not endemic but our desire is for it to be zero ...

Re: Broken luff track?

Posted: Tue Jul 15, 2014 1:45 pm
by avendit
Just found this topic, unfortunately just after ordering some track from ovi's and some Plexus from some random internet supplier, probably too late to cancel now. That said, couple of questions;

1) do I need a special applicator gun for the 380ml Plexus cartridges? I have a normal one for doing bathroom sealant etc, will that work?
2) The damage I have is the typical problem, bottom baton. Is it likely to be OK to sail in the mean time or will it just pop out on the first gybe?

Thanks!
Andrew
MPS255

Re: Broken luff track?

Posted: Tue Jul 15, 2014 3:23 pm
by Rick
avendit wrote:Just found this topic, unfortunately just after ordering some track from ovi's


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You will need a special nozzel which mixes the parts of the plexus; not sure if it comes with the tube or not.

Not sure on the second part; how bad is it?

Re: Broken luff track?

Posted: Tue Jul 15, 2014 5:51 pm
by paul manning
Andrew

Although Rick is absolutely right, you should be able to push a screwdriver or piece of wood etc down each nozzle onto a piece of card and mix in equal ratio...

Regarding the damage, as Rick says, it really depends how bad it is...

Re: Broken luff track?

Posted: Wed Mar 29, 2017 7:10 pm
by andyrice
Any views on if it's OK to use Plexus that's past its use-by date? I've borrowed some which expired July 2016.

It's for gluing back on a large chunk of track which stripped away from the hounds to the join between top and bottom sections, so about six foot I think.

Any expert views out there?

If I do need to get some new Plexus, any recommendations? [please not Selden! Unless their customer service has improved lately]

Thanks

Andy

Re: Broken luff track?

Posted: Wed Mar 29, 2017 9:47 pm
by DangerBoy
I've used it past shelf life before, but only for shorter batten end pieces about 1' long. Always bonded well though.

Recently I've had the kits from Selden that have come with the gun (have a shed full of guns now!)

RS seems to be as good a place as any as their postage is much cheaper than Ovington though.

Mark

Re: Broken luff track?

Posted: Fri Apr 07, 2017 10:29 pm
by sandyday
Adsupply.co.uk are quite cheap for plexus.

About £25 for a tube. They sell the nozzles too. I don't know if they sell the gun.

Re: Broken luff track?

Posted: Thu Jun 08, 2017 9:51 am
by Iane
Hi
Unfortunately broke my mast track last night
In this thread it says Selden will provide a kit FOC is this still the case?
Cheers
Ian

Re: Broken luff track?

Posted: Thu Jun 08, 2017 11:47 am
by Rick

Re: Broken luff track?

Posted: Sat Jun 10, 2017 8:58 pm
by GER170
I have had some further thoughts on the mast track:

Salvaging methods
-Use a 80mm carbon tube with a wall thickness of 1mm and cut sections out of it (the mast track has an arc of approx 80mm on the outside). Glue one section each side onto the outside of the mast track sides using acrylic glue, approx 100m in length. This will significantly locally increase strength of the track. Only do this in the Acres of the lower three battens (where most damage occurs). This will have no practical impact on mast stiffness. However, to avoid misuse, the use would have to be limited to lengths of say 100mm at the bottom three batten locations.
-Use a 3D printer to print sections of the mast track in tougher (not stiffer, for example nylon 66) plastic than supplied by Selden and use this as salvage sections in the areas of the batten pockets.
@Technical committee: would you give green light to trials of this nature and use the mast in upcoming regattas?
@all others, anyone would like to support these trials?

Finding a new superior track:
-on the water trials would be sufficient to be carried out by replacing the current track with new track in the batten areas (no the whole length of mast), this would significantly simplify trials
-the track would have to be verified by a destructive laboratory test to be superior to the current one (impact test with steel ball for example).
-The obvious solution would be to use a tougher grade extrusion material for the track, it is within Seldens Power to implement this and the cost would be minimal to them.
-the locally reinforced track as per above could be a (if not elegant) solution for serial production too
@Technical Committee: could you please inform Selden of the above and ask for their support?

Re: Broken luff track?

Posted: Sun Jun 11, 2017 4:50 pm
by paul manning
Hi Iver

I'll drop technical a mail for their thoughts and post their feedback here.

Re: Broken luff track?

Posted: Wed Jun 14, 2017 11:28 am
by bristollad
or reduce the size of the batten pockets on the sail :roll: