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 Post subject: Re: Skin Repairs
PostPosted: Mon Jul 11, 2016 4:32 pm 
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Dear All,
one of the samples that has been on test since (I believe) last October and which has yet to succumb to the efforts of either Mother Nature or Unilever is polyurethane backed cordura nylon canvas.
Last weekend I sewed together two pieces of this with a single row of cotton stitching on my 1917 hand cranked singer sewing machine. Nothing fancy. A strip of iron on waterproof seam tape was then ironed on. The sample was then subjected to a colander test. (line a colander with the fabric, fill with water and leave it.) After an hour or two it started to weep slightly so I dried it off. A strip of iron on tape was then applied to the other side and the iron run back over the first tape pressing well into the corners of the seam. This then stood up to a couple of hours in the colander without incident so it shall shortly be subjected to the full bucket test. (Saltwater and surfactants).

If this works then it would open the possibility of stitching a kayak skin in a multi panel fashion like an airship on a domestic sewing machine and ironing board. Probably best avoid rocky shores though.

Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Thu Jul 14, 2016 3:29 pm 
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Dear All,
the seams on the cordura nylon sample have failed. I could not see any failure on the seam but patently they were not watertight as the sample admitted half an inch of water in twelve hours.

Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Wed Aug 03, 2016 4:22 pm 
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Dear All,
After much burning of midnight oil the skin of my Tyne has been scraped in the keel strip area.
Tyne kayaks and probably old Kleppers have a five ply skin. Tow layers of canvas sandwiching three of rubber. The keel strop of mine had been attached with what I believe to have been contact adhesive which was made from petroleum (gasoline). Petrol attacks rubber and the long term consequence was that the adhesive had rotted the rubber coating to the skin. The remnants of existing rubber were removed very painstakingly with a curved scalpel and heat gun. A scraping action was employed to remove the perished coating. The heat setting was on the lower side of mid and the scalpel was frequently reground on a diamond stone. A few small threadbare patches were uncovered as I went along and these were plugged with Stormsure.
Silicone was removed from the keel strip with the curved scalpel. I tried a sealant removal tool in my multitool but found that this had a horrible propensity to dig in so desisted in its use. A slicing action was used to remove the silicone.
The kayak has been reassembled and a first coat of Gummipaint applied.
Two more coats will be required followed by silicone to re-attache the keel strip.
I have an appointment with friends on Sunday and the kayak needs to be ready by then so it will be a coat a day followed by silicone on Saturday and hopefully bon voyage on Sunday.
I shall keep you posted. I feel confident as it is already known that both silicone and gummipaint are effective the problem was that I had failed previously to uncover all the degraded material and make good.

Anon,
Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Wed Aug 03, 2016 5:39 pm 
lord high faltbotmeister

Joined: Fri Oct 07, 2011 1:51 pm
Posts: 602
Location: Colombo, Sri Lanka
Good luck with this and please keep up your great research! My father was a wizard with a scraper and I remember how much care he tok to get a suare edge on it....

I hope you make your deadline :-)

_________________
Simon

Pakboats Quest 135, Nautiraid Narak 460, 416 & K1 (sold my 550), First light 420, Feathercraft Wisper, Fujita Alpina AL-1 400, Incept k40 (for sale)
Non-folders: Cape Falcon F1. Beth sailing canoe, 2014 Hobie Adventure Island


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 Post subject: Re: Skin Repairs
PostPosted: Sun Aug 07, 2016 6:15 pm 
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Joined: Wed Dec 02, 2015 7:15 pm
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Dear All,
Today my much repaired Tyne Double succeeded in negotiation the very weedy flat water of The Wey and Arun Canal. There was very little water in the bottom at the end.
I have had some trouble persuading the rubber reinforcement to adhere to the hull skin at the bow and stern. Contact cement provides grab but the result of contact cement is not a happy one. Having painted three coats of Gummipaint over the bare keel strip area I and my daughter then brushed thinned silicone over both the hull and the keel strip. With the skin previously assembled onto the frame the keel strip was held until the silicone adhesive / sealant cured by masking tape wrapped around the hull. At the bow and stern I shall have to make a shaped block so that I can glue the keel strip and then clamp the keel strip in place until the adhesive sets. When peeling off the masking tape it took some old proofing off the line of a stringer which I temporarily duck taped over. The day was a success so I shall make a few more tweaks as described above and hopefully it will be like the Nullabor inside next time.
Anon
Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Fri Aug 12, 2016 7:45 am 
Brotherhood of the Golden Paddle
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Joined: Thu Apr 14, 2005 4:47 pm
Posts: 1709
Location: Arlington, VA (i.e. Wash DC)
Hi Malcolm,

Thank you for continuing to update this with your results.

I note your comment that both silicone and gummipaint are effective, and that the trick is to have removed the old material. Gummipaint does not appear to be available in the US, so that would leave me with silicone.

Thank you,

_________________
Chris T.
~'91 Klepper A2 w/ BSD schooner rig.
'64 Klepper Passat/Tradewind and T12 restoration projects.
Non-folding: '84 Hobie 16; early '90s Old Town Canoe.
Previously owned '04 Pakboat Puffin II and '05 Swift.


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 Post subject: Re: Skin Repairs
PostPosted: Fri Aug 19, 2016 6:55 pm 
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Dear Chris,
to the best of my knowledge Gummipaint is not available in the U.K either. I order it online from Yachtshop24 in Germany. The website is in German but it works like any other online shop and it is obvious where to click and payment with Paypal obviates filling out payment or address details.
Are you suggesting that Gummipaint is prohibited in the U.S.? I know that I have been unable to import some Rust-O-Leum products from the U.S. I have also been clobbered with £75.00 import duty on a cordless drill from the U.S. So much for the U.S and U.K being bastions of free trade. Only when it suits it seems.

Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Fri Aug 19, 2016 7:07 pm 
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Joined: Wed Dec 02, 2015 7:15 pm
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Dear All,
The Tyne Double slips through the water beautifully. Whilst out on the Wey Navigation in Surrey with some tyro friends last weekend I was overtaken in it and mistaken from astern for a Klepper. Sadly all is not yet well as although the keel area was scraped and Gummipainted the rest of the hull is mightily flaky and yards of duck tape saw me through the day. The remainder of the hull is now being scraped. When scraping the hull with a curved scalpel blade the blade is frequently re-ground such that it has become nearly a stub and will be replaced. When scraping the resultant flakes are frequently swept up and in doing so much dust is produced. It would be best done over a bench outdoors or in a garage I feel. It took a long time to vacuum the dust off my lounge. ( I live in a rabbit hutch of a house). Additionally as the keel strip was re-attached with diluted silicone the adhesion has not been perfect along its edges probably partly attributable to the ribbed frame of the kayak with resultant impossibility of clamping adequately. I have thus been working my way along the edge of the keel strip using neat silicone and latterly Stormsure to stick down any loose sections of keel strip weighting them down overnight to set. This is done with the skin off the frame. The skin had crazed a lot more recently probably doe to the frequent rolling and flattening whilst undertaking scraping of the keel strip area. This has at least facilitated removal of the old perished rubber.
I hope to re-float by September the 10th.

Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Sat Sep 24, 2016 6:02 pm 
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Dear All,
after a valiant campaign of resistance against the enemy forces of moisture and mould the silicone coated canvas sample has given itself up to the mercy of mother nature. The Gummipainted sample however continues its resistance. The Gummipainted canvas sample has been removed and painted with two coats of Bedec Multi Surface Paint. This is satin silver colour in an attempt to mimic the silver finish of a Tyne skin. Two coats of multi surface paint have obliterated the orange of the Gummipaint. The sample was cleaned with HG mould spray to kill the mould before re-coating. The sample has been re-attached to a frame and immersed.
In the mean time the cordura nylon sample runs and runs with no sign of leakage or even mould presumably because its synthetic fibres provide no nutrition for any living organism. In view of the resilience of the Cordura nylon I have rather set my heart on finding a way of stitching this together and water proofing the seam. I may have just done that. I have stitched together a sample with the seam right across the middle. The seam was sewn as a flat fell seam with cotton thread and then treated with McNett Seamgrip. On the colander test I was incredulous to note a slight weep but nothing daunted a second application of Seamgrip was made and this stood up to 24 hours of testing in the colander so this seamed sample has been attached to a test frame and immersed. Fingers crossed.
Anon,
Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Mon Sep 26, 2016 5:12 pm 
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Joined: Wed Dec 02, 2015 7:15 pm
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All is well with both the seamed cordura nylon and Gummipaint with multi surface paint this far.


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 Post subject: Re: Skin Repairs
PostPosted: Tue Sep 27, 2016 8:33 am 
Brotherhood of the Golden Paddle
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Joined: Thu Apr 14, 2005 4:47 pm
Posts: 1709
Location: Arlington, VA (i.e. Wash DC)
Hi Malcolm,

I'm not aware of any prohibition, although I don't imagine it would come by air. I am wary of the various problems of getting things through customs, too. And shipping from Europe can be expensive (although sometimes not, too).

_________________
Chris T.
~'91 Klepper A2 w/ BSD schooner rig.
'64 Klepper Passat/Tradewind and T12 restoration projects.
Non-folding: '84 Hobie 16; early '90s Old Town Canoe.
Previously owned '04 Pakboat Puffin II and '05 Swift.


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 Post subject: Re: Skin Repairs
PostPosted: Tue Oct 11, 2016 3:02 pm 
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Joined: Wed Dec 02, 2015 7:15 pm
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Dear All,
the sample of cordura nylon stitched with cotton and sealed with Seamgrip along with the sample painted with Gummipaint and multi surface paint have just successfully exceeded a fortnight of immersion. The test continues.

Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Tue Oct 11, 2016 3:14 pm 
Brotherhood of the Golden Paddle
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Joined: Thu Apr 14, 2005 4:47 pm
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Location: Arlington, VA (i.e. Wash DC)
Thank you Malcolm-- good news!

Are any of us able to get an idea of the composition of gummipaint, and/or an equivalent in the US?

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Chris T.
~'91 Klepper A2 w/ BSD schooner rig.
'64 Klepper Passat/Tradewind and T12 restoration projects.
Non-folding: '84 Hobie 16; early '90s Old Town Canoe.
Previously owned '04 Pakboat Puffin II and '05 Swift.


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 Post subject: Re: Skin Repairs
PostPosted: Thu Nov 10, 2016 6:53 pm 
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Joined: Wed Dec 02, 2015 7:15 pm
Posts: 49
Dear All,
The cordura nylon seamed in a flat fell and sealed with Seamgrip is still watertight as is the Gummipaint, overpainted with Multi surface paint.
Gummipaintis a hypalon paint intended for the painting of inflatable and rigid inflatable boats. I previously tried a British manufactured hypalon paint which whilst it may have been good for its intended purpose was no use at all for canvas as its viscosity was very low. It may be possible to obtain another Hypalon paint in the U.S. (before Mr. Trump deports the factory staff, delivery drivers etc.) but it would be wise to test a small sample first. If it bleeds like ink then it will be no good. A viscosity akin to that of gloss enamel paint is that which is required. On a tin of Gummipaint it is stated as being Polyurethane enamel. I think that it is worth reiterating at this stage that three coats of Gummipaint were required to adequately close all the pores in the canvas sample under test. The sample was held up to the light and examined as closely as my ageing eyes will permit. Pin holes were still visible after two coats but were closed after three.

Malcolm Tierney


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 Post subject: Re: Skin Repairs
PostPosted: Fri Nov 11, 2016 3:17 am 
knight of the folding kayak realm

Joined: Wed Oct 07, 2009 6:42 pm
Posts: 421
Malcolm, thanks for reporting all your research here.
Ian


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