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Alternative sponson

Posted: Thu Oct 06, 2016 12:39 pm
by joypad
Hi, i'm building a yost sonnet 16.
I had trouble finding sponsons (i live in italy), found them in germany, but are quite expensive...
At first i thought to build tubes with pvc, but it's not recommended, so i thought to use bags for vacuum preservation of food, i've found tubes 6m long and 15cm wide so i can make heat sealed sponsons of the lenght i need.
Just sharing my idea, hints and suggestions are appreciated!

Regards, Jacopo

Re: Alternative sponson

Posted: Fri Oct 07, 2016 7:56 am
by AndiG
Hi Jacopo,

I would not recommend to use food preservation bags, the foil normally is too thin and easily damaged. Also film tubing, as it is used by roofers (http://www.ebay.de/itm/10m-Folienschlau ... 1491663592) is too thin for this purpose.

It is not so difficult to make sponsons but I´d suggest to use heavier pvc. For my first set of sponsons I bought pvc with 300g/m2 which turned out to be not airtight, so I had to make them a again and this time I used the same material as for the skin (650g/m2).

Kind regards,

AndiG

Re: Alternative sponson

Posted: Fri Oct 07, 2016 10:17 am
by joypad
that's the first thing i thought, but i also thought that the sponson is protected by the sponson sleeve and the hull, don't you think?
airthightness seems not a problem, i left an inflated sponson with weights on it for few days, no air loss at all

Re: Alternative sponson

Posted: Wed Oct 12, 2016 7:53 am
by AndiG
that's right but on the other hand it is very easy to get dirt, sand, little pieces of shells, etc into your boat and you will never get them all out again. They will rub on your skin and the sponsons. The thinner the sponsons are, the easier they get punctured. I measured my spare Klepper sponsons, their pvc is 0,4mm thick and they had already a hole from a rough landing.

Re: Alternative sponson

Posted: Sun Jan 08, 2017 3:37 am
by dschin
does someone test inflatible poolnoodles?

Re: Alternative sponson

Posted: Sun Jan 08, 2017 10:44 pm
by chrstjrn
I have kid-tested inflatable pool-noodles in a pool and in a river with sharp rocks. They are surprisingly tough.

Re: Alternative sponson

Posted: Mon Jan 09, 2017 2:53 am
by siravingmon
The issue is that a specific length over 16'and diameter 3.5"(?) is needed for this particular application

Re: Alternative sponson

Posted: Mon Jan 09, 2017 10:13 pm
by dschin
simon: thinl about takeing 2 instead of one. if one is deflated/destroyed you will have the other one instead of none.
chris: thanks

Re: Alternative sponson

Posted: Tue Jan 10, 2017 2:50 am
by siravingmon
In that case I suggest you research available detachable sponsons from shorter kayaks eg Advanced Elements for use nose to tail

Re: Alternative sponson

Posted: Tue Apr 18, 2017 6:44 pm
by overland
Pakboats have three small inflatable sponsons (attached to each other) on each side. I wonder if those might work--at least for the 14/6 Sonnet. I've sometimes thought of making a Sonnet, but finding sponsons seems to be getting harder. And the available instructions are pretty sparse.