Skin Repairs

[gbellware]

Sorry Malcolm, let me clarify:
Michael (Edelman) is the founder/moderator/webmaster of this board, so my suggestion to him was to make

"sticky"

your tips on skin repair. A "sticky" is a thread that stays at the top of the discussion category to which it relates, for example:

viewtopic.php?f=36&t=1245
is a very useful thread on rivets that appears at the head of the category "kayak repair", and it was this category that I suggested your thread be put in a "sticky".

Thanks again for the contribution.

g

[MalcolmT]

Thank you for the enlightenment. My ability with wood exceeds that with I.T.
Malcolm Tierney

[overland]

Can one buy Gummipaint in the United States?

[chrstjrn]

I just made it sticky

Malcolm-- please take it as a complement. The rest of this think this is so important that it should headline the entire section of the forum. Click on Kayak Repair under "Board index » Kayaks » Kayak Repair", in the upper left, and you will see what we mean.

Thank you again for your contributions.

[overland]

I've looked on ebay for Gummipaint, as Malcolm suggests. There are definitely sellers, but they all say they cannot ship to the United States. I've not been able to find a U.S. seller. Has anyone had better luck?

[overland]

The Skin Boat Store in Washington state sells a urethane coating. Does anyone have any experience with it? Would it work? How would it interact with Hypalon?
http://shop.skinboats.com/Urethane-Coat ... 4gokit.htm

[MalcolmT]

I am very sorry if Gummipaint is not available in the U.S. Mine was shipped in from Deutschland. It may be possible to find an alternative Hypalon paint made in the U.S. What you want to be sure of is its viscosity. As you may remember the first hypalon paint that I tried was made in Wales (U.K.) but was too viscose and bled through with no hope of closing the pores in the fabric. You can rest assured of the durability however of Dow corning silicone as my silicone sample is still sitting in salt water and surfactants seemingly impervious to their actions and watertight.
Maybe if you have any friends going to mainland Europe (Gummipaint is Italian) they may be able to bring a tin back in their hold luggage. (Or would this cause trouble?) (No one move, or this plane gets watertight!) (Really?)

Malcolm Tierney

[MalcolmT]

Dear All,
having conducted sufficient test I felt that it was time to put my money where my mouth is and get on with it.
I have sanded the skin of my Tyne to remove any raised crazing. There were areas of spalled rubber coating. In an excessive fit of zeal I started to plug any holes with Stormsure but got a bit carried away and applied it too many of the bald areas. I wish that I had not because even though I applied it with a brush supplied with the Stormsure it ran in places and is a bit lumpy and therefore unsightly but it has adhered and is very tough. Some of this I may persuade away with a curve scalpel blade. A few small holes were present in the canvas where the skin had been folded and the canvas had frayed. Stormsure is perfect for this.
After the rub down with 120 grit to remove loose skin and key up it was cleaned with tack cloths and then again with rags and methylated spirits (wood alcohol stateside). A coat of Veneziani Gummipaint has been applied. As most of the hull skin is still rubberised the coverage is considerably greater than on an untreated sample. I shall apply a second coat to the bald areas and trim the Stormsure then a final coat.
As a matter of interest to some I just found a receipt from Tyne Boats dated 1st April 1969 acknowledging payment for keel strip and rubber solution which neatly answers my question as to how to re-attach the detached keel strip.
The instructions state:
"It is advisable to remove old paint* with very fine sandpaper, using same lightly only. Apply thin coating of solution to hull and keelstrip working 2-3ft. at a time only allowing solution to get tacky, i.e. 30-60 seconds."
There was a tube of rubber solution in the box in which the receipt was found along with 'Lasso Tape' which had been applied to the skin to reinforce it along the lines of the lower ribs.

*From this one may infer that the hull had a flexible painted finish.


Malcolm tierney

[idc]

Thanks for this, Malcolm. Really looking forward to hearing how it goes once you've applied the final coat and taken it for trials.
All the best,
Ian

[MalcolmT]

Dear All,
Two coats of Gummipaint seem to be sufficient. I am wary now of adding a third to an already treated skin for fear of overly stiffening it. the Gummipaint has been well worked into all the bald areas.
If anyone else wishes to try this I would recommend using Stormsure only on holes. Gummipaint will happily deal with the rest.
I attempted to use 'Pang' brand vulcanising solution on a piece of old inner tube as a prelude to reattaching the keel strip. It failed.
Two tins of 'Schrader' rubber cement have been ordered and hopefully more success will be had with those.
Sadly Veneziani do not make a silver Gummipaint. Grey is the nearest fit so my Tyne now has a grey hull. Battleship grey. This is a pity since I was rather fond of the aluminium (yes, aluminium) finish on the hull. It seemed redolent of the exciting period of experimental post war craft such as the SRN1 or prototype DeHavilland Comet etc. Oh well, one can not have everything.
Anon,
Malcolm

[chrstjrn]

Thank you for your contributions, Malcolm.

We would love to see photos!

[DLee]

Yeah, great stuff. Photos needed for sure.

d

[MalcolmT]

Dear All,
My son has never been in a kayak so I decided to kill two birds with one stone and take him for a turn around a local boating lake in Danson Park, Bexley (U.K.) and give the Tyne Double its maiden voyage post repair. It was the first time that I have paddled a Tyne and it really is a lovely design. It slips through the water beautifully. Sadly there was some water ingress. After one circuit of the lake there was approximately 5/16" of water slopping in the bilge. After lifting out and sponging dry another circuit was made with the same result. (Don't panic.) In the course of sponging the deck dry whilst stowing some blue colour (paint? dye?) came off on the sponge. A little curious but not too worrying. Whilst exhuming the mortal remains of the Tyne's skin from the car post paddle it was found that although the silicone had adhered in attaching the keel strip, that to which it had adhered was degraded and not integral with the canvas any longer. It was thus possible to pull away the rubber keel strip from the canvas and its perishing rubberised coating. There is still hope I believe. By removing any further failed coating from the keel area and painting with Gummipaint it should be possible to re-attach the rubber keel strip to a more sound substrate. An attempt shall be made to clean any remaining coating from the canvas in the keel strip area and from the rubber with a multi tool and knife blade attachment. A coat of Gummipaint to make a new good surface followed by re-attachment of the keel strip with silicone (again) and hopefully all will be well.

It would seem a good idea given the superannuated skin to the Tyne to make a new p.v.c. skin (I can't run to Hypalon sadly.) At some point there was a link provided to a blog where someone had made a skin in panels airship fashion. Unfortunately I was not able to follow the link. I do not like the idea of stretching a sheet material into a compound curve. It was very difficult and not perfect on my rigid PBK20 so on a folder it would be trickier. With Tom Yost's method it would seem difficult to sew on a canvas deck because the lacing has to remain whilst the deck is attached. With panels lacing may not be required as the skin can conform to shape through guile rather than brute force. Thinking about the similarity of these works to upholstery and the use of paper patterns it would seem possible to tape sheets of newspaper together then attach to the frame with masking tape. A rub over with a brass rubbing crayon would give the line of the ribs. A margin could then be added to this to allow an overlap and the panels joined with simple lap joints. Once the panels had been assembled the hull could be reversed and the deck stitched on. A line of Seamgrip or Stormsure applied to the seam and the skin turned back out. A double layer of p.v.c. could be applied to the keel or a layer of rubber though rubber does not like being folded. I found a sheet of rubber in my lock up which was used about ten years ago to attach roofs to bird boxes and at the corner of the fold it had failed.
Anon.

Malcolm

P.S. I have been rather remiss with the camera. The skin as repaired is rather wrinkly and not a thing of great beauty but 'handsome is as handsome does' as they say in Yorkshire.

[MalcolmT]

Dear All,
I have just tried to attach a photograph of my Tyne double's inverted and dilapidated hull but the site tells me that the file size is too big. I.T. is not my forte. Any help with this would be appreciated.

The area under the keel strip is almost devoid of its rubber coating. The adhesive that had been used to attach the keel strip had attacked the rubber coating. I understand now that Tyne hulls were made of rubberised canvas which is a five layer lamination. Two layers of canvas sandwiched and coated with rubber. It would seem from the enquires that I have made that rubberised canvas is now ancient history. It would also seem that some of the rubber o my Tyne's hull is ancient history. In an effort to ascertain further the dilapidations to the hull I have taken it from my lock up garage to my home which has no garage and a garden the size of a postcard. My lounge is only eleven feet long and the Tyne is seventeen approximately. The frequent rolling and unrolling of the skin is revealing furthert areas of rubber dandruff being deposited over the lounge floor. I have succeeded in removing areas of rubber that have crazed with nothing more fancy than a thumb nail. This is quite good therapy. The keel area is being scraped with a curved scalpel blade held at a right angle to the surface of the canvas. A heat gun is quite useful on areas with remnants of adhesive. It is apparent however that the two layers of canvas have delaminated. There are in addition a few small frays. Once I have removed any further loose or rotten rubber a coat of Gummipaint will be applied followed by Stormsure to frayed areas. I am marking frays with a ball pen as I go so as to know not to paint them and thus leave them ready for Stormsure. the silicone stuck to the keel strip like a terrier to a rabbit but not to the hull as the surface was friable. One the keel area is cleaned and scraped and painted a good bond should be achieved between Gummipaint and the rubber keel strip. The keel strip appears to be canvas reinforced rubber and in canny fettle. The multitool is most effective in removing silicone where peeling will not. Do not hone the blade or you will cut into the substrate. Always keep the blade flat to the surface.

Malcolm

[chrstjrn]

Lots of work, from the sound of it!