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 Post subject: Re: Skin Repairs
PostPosted: Sun Dec 11, 2016 12:04 pm 
Brotherhood of the Golden Paddle
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Posts: 1709
Location: Arlington, VA (i.e. Wash DC)
Thank you for everything, Malcolm.

I hope you noticed the post, elsewhere, regarding "LineX".

http://www.foldingkayaks.org/phpBB/viewtopic.php?uid=8&f=27&t=6825&start=0

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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: Mon May 29, 2017 4:30 pm 
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Joined: Wed Dec 02, 2015 7:15 pm
Posts: 49
Dear All,
I thought it best to give an update. The Tyne did not behave so well after its second outing and was leaking again.
This project went on hold though as I built a second PBK20 and a pair of lightweight hollow paddles then unexpectedly took on a bindweed infested allotment and ended up building a rotary screen to sieve it. The Tyne has now progressed however. The rubber was stripped from the canvas from the keelstrip (which was previously stripped and painted) to the deckline. This was done with a heat gun and a home made wooden scalpel handle after it was found that the original brass one became too hot to handle even with gloves on.
It was not possible to remove absolutely all the stormsure that had been applied in an earlier attempt at repair. A good number of small holes and frays were found in the canvas where it had been forced to assume tight bends where the rubber coating had cracked. these were patched with Stormsure. The hull has been given three coats of Gummipaint on the starboard side and two on the port. Another coat shall be applied to the port tomorrow. It is due out on the Basingstoke Canal on Saturday and I shall report back.
Of the test samples all have now failed except the unjoined piece of cordura nylon. The silicone, gummipaint and nylon seamed with Seamgrip all exceeded a year's continuous immersion at air temperatures of -5 to 30 degrees in brine with surfactants. I think that can be considered a success. As for cordura nylon, that is only intended for seat covers!
Anon,
Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Sun Jun 11, 2017 4:31 pm 
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Joined: Wed Dec 02, 2015 7:15 pm
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Dear All,
The Tyne has been taken on the Basingstoke Canal (In the U.K). I sat astern and my daughter forward. There was no ingress of water visible at all forwards or amidships. Only when we took out was some discovered to have leaked in. All this came from astern and I believe that the small amount of water that came in came from the very end of the stern. On the bow and stern are rubber reinforcements applied with contact adhesive by a previous owner. I deemed these just too tricky to remove and still do. However some of the joint has failed especially above the waterline. I am working to rectify this with further Stormsure and Gummipaint. As I am in the habit of stern launching I believe that this is when any moisture came in. On this occassion my daughter and I used the spray deck so that I could see that not only had nothing entered the vessel before lunch but the results were not confused by paddle drips. It really was as dry as the Nullabor. Unfortunately my daughter and I are not used to using the spray deck and managed to dump the water off it into the hull. D'oh! the spraydeck had been treated with Fabsil Gold and the paddle drips sat on it like beads of mercury. The deck has yet to be treated.
The Tyne should (weather permitting) be out again this on Saturday 17th June on the Medway so hopefully that weeping at the stern can be eliminated.
I feel pretty vindicated in the use of Gummipaint and look forward to using the Tyne further though sparingly as this is a fifty year old craft. Next week I intend to do that which was intended for folders; namely to paddle one way then pack it and take it back to the start by train. As there are no longer luggage vans on most trains this may be a little interesting.
On a previous outing for the Tyne I applied much duck tape to the hull on top of the failing rubber and gummipaint. After remaining in situ for months the duck was removed. It behaved like paint stripper and left virtually vegetable canvas behind. If you are paitent and feeling flush it may be possible to strip perished rubber from a hull skin using duck tape. also presumably because it was petroleum based the contact adhesive that was used to attach the keel strip way back when telephones were made of bakelite had also destroyed the rubber coating. This should be borne in mind before attempting to attach any reinforcement to a rubber or rubber coated skin.
In his books on boat building Percy Blandford refers to black reclaim cement. Does anyone know what this is or what a modern equivalent would be?
Anon,
Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Sun Jun 18, 2017 5:54 pm 
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Joined: Wed Dec 02, 2015 7:15 pm
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Dear All,
Well here is an unexpected addendum to the topic of repairs. I took the Tyne out on Saturday to the Medway and paddled the twelve miles (according to my map measuring tool on the 1:50,000 Ordanance Survey map) from Tonbridge to Yalding. there was still a little water in the bilge at the finish. Not a lot mind. I shall apply another coat of Gummipaint. It seems that canvas may shrink with age. I have always had quite a job tensioning the canvas onto the frame but this time as the bolts on the coaming were being tightened a joint failed on frame number five. The glue line failed. My daughter and I paddled anyway without incident. the boat was packed away and having removed the old perished rubber it was now possible to pack the skin and frames away in one bag which had not been possible previously. In transit via the train however one of the ribs on frame five now being solely stressed broke up. I notice that the plywood was stout heart ply. i.e. it had only three laminae: two outer structural veneers and a stout centre. This type of plywood does tend to be rather weak. the intact half of the pair was drawn around on a sheet of 5.5mm birch plywood. the recesses for the stringers and gunwales were drilled out first with a cordless drill and flat bit followed by the remainder with a coping saw then spokeshaves and finally aluminium oxide paper. The new part and the intact old one were then glued back to the remainder of the frame with West System marine epoxy. For those who do not do much woodwork I would stress that firm even clamping pressure is vital to the final strength of any glued timber joint. I clamped the entire frame no. 5 to a sheet of plywood wood keep it all flat whilst setting. If you do not want to stick an assembly to that which it is being clamped upon then vinyl parcel tape makes an admirable parting agent.
Taking a bit of pride in the old boat I decided to start a programme of varnishing the timber components. rubbing down first with lubricated silicone carbide paper first and between coats is a must for a good finish. I always wipe over with a tack cloth before applying a coat. The brass fittings were removed from the coamings before rubbing down the timber and the brass fittings themselves were removed for polishing. I don't think that it had been done in half a century so the tarnish was like a bread crust. Some items were wire buffed with a polishing wheel and compound. I used my lathe but a power drill in a horizontal stand would have been better and a set of grinding wheels fitted with a polishing wheel better still. Other fittings were rubbed with wire wool and all were much polished with a rag and Brasso. new brass screws were used to re-fit the brass components. Here comes the fun part. On the journey several of the screws exited the timber. The old holes had become somewhat enlarged from corrosion. I really should have known better than to re-use the holes unaltered. Today all the fittings were removed and polished again and the screw holes were drilled out to 6mm diameter leaving the holes blind (Not drilling right through). Beech dowels were then glued with Gorilla polyurethane glue and driven into the holes. These were then cut flush. Just like that. Not quite.
In attempting to make this post I apparently exceeded the maximum number of character. (Not one of the 'twitterati' I).
Please see the next post for a continuation.
Anon,
Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Sun Jun 18, 2017 5:59 pm 
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Joined: Wed Dec 02, 2015 7:15 pm
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Continued.

The piece of brass with the hole in was cut off to a size of approximately 5" x 2 1/2". The hole was laid over the dowel on the workpiece and with a tenon saw on its side the dowel cut nearly flush. Do not use a hardpoint for this as it will catch the edge of the brass sheet and do it a mischief. the remains of the dowel was then cut flush with a 1" chisel with a slicing action. the chisel does need to be properly sharp for this. The brass parts were then re-positioned spot drilled through, the holes pilot drilled and the new brass screws driven in. When driving brass screws into hardwood it is always a good idea to lubricate the thread with a candle.
I hope that this may be of use to other timber framed boat owners.
Anon,
Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Mon Jun 19, 2017 3:47 am 
knight of the folding kayak realm

Joined: Wed Oct 07, 2009 6:42 pm
Posts: 417
Dear Malcolm,
That is all of a great deal of use. I would love to see photos, but I remember (I think) that you didn't think you'd be able to post photos. Still, perhaps we'll be able to have a UK folding boat get-together or Tyne owner get-together at some point and I can view your work then. I'm very impressed with what you're doing here. I had my own Tyne Prefect out on the water on Friday and was reminded of just what fantastic boats these are. They do require some upkeep. In my case it was the canvas on the bag that gave way this trip--unhelpful as I needed to walk the thing to the station to get home. Thankfully I had enough duct tape with me to get it home. I guess I'll have to sew a new one in the long term though. The boat (which has a new glued and sewed skin of my own manufacture (with considerable help from my 84-year old mother on the sewing of the cockpit) is hopefully OK, though there is a temptation to have a second go at reskinning it to correct a few things I wish I'd done better. (In brief, I duplicated the original canvas inflatable coaming, formed around a bicycle inner-tube, but this isn't strong enough to hold a spray skirt, so I wouldn't mind a skin using a more klepper-like wooden coaming or yost-like aluminium one so that the boat can be sealed when taken on big water like the sea).
Anyway, thanks for all the information you share here. Well done and enjoy your boat!
All the best,
Ian


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 Post subject: Re: Skin Repairs
PostPosted: Mon Jun 19, 2017 4:40 pm 
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Joined: Wed Dec 02, 2015 7:15 pm
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Dear Ian,
Thank you also for your post. I really would like to meet up especially now the worst is over and I have a functional fleet of kayaks to entertain my friends. (Shame about the allotment). The Tyne Sprint Double has rings of very stout rope sewn into the canvas openings although I do not know how well this works as the spray skirts supplied with mine have become stiff and the elastic has perished. The spray deck on the Sprint double is a real nuisance to fit. It takes ages and neither my daughters or my friends Mark and Adam like it as it takes so long to fit. I have not seen the wooden ring in a Klepper deck. I recently made a stem chest and it may be a relatively simple matter to make one if it is a flat ring of circular or elliptical plan even if of a half round or dowel section. Perhaps you may like a hand with that? Ash would be indestructible but oak rigid.
I do feel tempted to make a p.v.c. skin myself as it seems the skin has shrunk and is placing undue strain on the frames witness Saturday's failure. Works to my kayaks are mostly carried out in my lock up which is off grid however and thus precludes the use of an electric heat gun for HH-66 unless I was to try this on the road outside my house.
Anon,
Malcolm


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 Post subject: Re: Skin Repairs
PostPosted: Wed Sep 13, 2017 2:49 pm 
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Joined: Wed Dec 02, 2015 7:15 pm
Posts: 49
Dear All,
The Gummipaint certainly works and so does Stormsure but one thing can not be repaired and that is the ravages to the integrity of the canvas. i have learned that my boat dates from 1958 and unfortunately the canvas has surrendered. It parted on a recent trip and had to be packed and carried. The skin was stitched back together and proofed with Seamgrip. Seamgrip has a brush applicator and thus is more suitable for this task. The Tyne was taken to Danson for a test run and took on water in a big way. On taking out it was found that the skin had parted again near the stern. At nearly sixty years old it has had a good run. It seems that p.v.c it has to be. It also became apparent that the canvas was shrinking as it was becoming almost impossible to tension the canvas onto the frame.
The bullet must be bitten.
Anon,
Malcolm


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