Build a Greenland kayak part 7

In this Instructable, part 7 of the Build a Greenland kayak series, you will be putting the skin on your Greenland kayak and attaching the coaming to the skin.

Step 1: Materials

Measure the length of your boat along the keel line and get that length plus one foot of fabric.
8 oz nylon is available from George Dyson [phone].
#10 canvas I don't have a source for, but art supply stores seem to handle it. Check the internet for sources.
I have lately been using mostly 8 oz nylon fabric. It is strong, easy to work with and lasts a long time. I have used heavier nylon fabric, but it is too strong and if the boat is left in the sun, the skin shrinks and warps the frame. Before you buy skin, measure your boat. It will be longer than 16 feet with the stem and stern boards in place. Width of the fabric should be sufficient to circle the boat in the cockpit area. If you can only get fabric in 48 inch width, you might have to sew some patches in the cockpit area. Buy a foot more material than the length of your boat.

In the past, I have used cotton canvas. If you use it in salt water, it can last a decade, but in fresh water, canvas starts rotting out after a few years and you either have to keep busy patching or replacing the skin within 5 years.

Thread - I use a nylon thread because it will not tear while I am sewing. With cotton canvas, I have used a cotton polyester blend string.

Varnish or Paint - On cotton canvas, I used to use house paint. With nylon, I have been using exterior polyurethane varnish. The varnish makes the skin translucent and the yellowish color of the varnish also gives the skin a natural sealskin look. Be sure to get exterior varnish. Interior varnish lacks UV protection additives and if you leave your boat in the sun, the skin will start to degrade.

Comments

[iKiwiKayak]

Thank you for the extremely detailed blow-by-blow instruction. I have a rather outlandish idea, which nevertheless I'd be very glad if you took the time to consider and give your own opinion.

As follows - completely dispensing with beam fabrication and using a strong nylon rope, lash and knot together the across from one gunwale through the stringers and kelson across to the opposite gunwale ... giving a completely different shape - an angular appearance. Very outlandish, I repeat, but potentially workable, manageable in the water? Be glad for your opinion. Thank you very much. Cheers

[nativewater]

Anything is possible if you can make it work. The reason for the deck beams is to fix the shape of the deck and also to support gear on deck. If you eliminate the deck beams then you have to stiffen up the ribs quite a bit, otherwise the boat won't hold its shape. The boat would then end up being quite a bit heavier.

[Nomadsanity]

What would you think about creating a suspension of clear silicone in white gas then painting or spraying that on the skin? The silicone will seal the skin yet be very tough and flexible after the white gas has all evaporated. I have used this to waterproof ripstop nylon for tarps and tents. I am not certain how well this would fill in the weave of the fabric, however, silicone sticks to itself very well so a smoothing coat of straight silicone could be added after the seal coat has dried. Thoughts?

[nativewater]

It will work as long as it sticks to the skin. It doesn't have to penetrate the skin. The main benefit to a sealer penetrating the skin is that it will still keep the skin water-tight even if you have surface abrasion.
You can always do a test patch of fabric and silicone and then hit it with some sandpaper to see if the silicone hangs on.
I tried some clear silicone caulk, the kind that comes in the tube for caulking guns once and it wouldn't stick to the skin very well. But I already had a base coat of varnish on the skin. I don't know if this is the kind of silicone you are talking about.
As for paint or any sealer which is a mix of liquid and suspended solids, the fabric acts like a filter and keeps the solids on the surface and limits how much of the liquid medium can penetrate into the fabric.
How much filling of weave the sealer has to do depends on how smooth a weave the fabric has. A lot of the synthetic fabrics have a pretty smooth weave and don't require a lot of coats to fill the weave.
In the end, if you have a new idea, there's no substitute for trying it to see how it works.

[Nomadsanity]

That is the purpose of suspending the silicone (just the inexpensive stuff in the tube) in the white gas. The white gas actually carries the polymer chains into the fabric allowing the silicone to form a composite with the fabric threads. The pieces that I have done showed a high level of abrasion resistance, are water proof, and there is also a higher resistance to tearing than the fabric by itself. Silicone and nylon don't stick well to each other so a surface application would peel off pretty quickly.

[Kynan4th]

Brilliant! incredibly detailed, if only there was one on a recovery kayak...
however, I believe I can use this, coupled with various other resources on the worldy widey webs, to craft myself a fine recovery kayak.

[nativewater]

Check the Sea Kayaker website and search for back issues or reprints of old articles. Mike Morris, I think it was had an article on how to build a recovery kayak spread across two issues. Mike Morris's book also had instructions. David Zimmerly's book qajaq has plans.

[get_awesome]

What do you normally use for flotation devices? Also, have you ever made one of these with a sealed rear compartment? It seems if you were so inclined, you could create another coaming, just like the cockpit but smaller, place it just to the rear, and craft some type of lid for it. Just a thought. Btw, insanely good instructable, more thorough than any I've seen on here so far. I started searching online for ideas on building a kayak, never done anything like it before, and ended up sitting here reading the entire thing in detail. It's now midnight, and I'm all excited to build my own kayak. Well done.

[nativewater]

I use air bags for floatation, one forward, one aft. You can buy these or make them yourself. Chris Cunningham has instructions in his book on greenland kayak building. People have done the hatches as you suggest. I haven't tried putting a bulkhead in a skin boat. And thanks for the kind words

[van62]

thanks for the info, love the instruction makes building this boat easy. built 2 already but i'm wondering if you have plans for making a spray skirt

[nativewater]

Instructions are out there on the web. I don't have any.
Chris Cunningham has some in his book on the Greenland kayak.

[van62]

i just purchased some 8oz cotten duck for $30 and was wondering if it is stiil good to use and what to cover it with any help would be thankful

[nativewater]

It's on the light end of the weight range that's suitable for covering a boat. So don't run the boat into rocks, but it should work.
If you like the raw fabric look, you can use exterior oil base varnish. Exterior varnish has UV blockers in it. Don't use interior varnish which doesn't.
You can also use exterior oil base paint - nothing special is required. house paint is fine.
Whether you use varnish or paint, you will need several coats until it fills the weave of the cloth and the surface of the hull is smooth. Paint will crack after a few years. Varnish will be less prone to cracking.
If you paddle in salt water, cotton will last longer than if you paddle in fresh water. Dry your boat well between uses and the skin will last longer.

[livetoride21]

Hey, I'm just wondering what material you used for making the rub strips?

[anyusername]

Hi,
Greetings from Chile. I have got rachel fabric, but here in my country, sellers are not used to oz. measurement. When i say "8 oz.", they don't understand. I bought a piece of something called 420 rachel fabric. Do you know whether there´s any system to convert these units?
Thanks
Aníbal

[anyusername]

Thanks, i think (and hope) that it will work. It's more or less like blue jeans material

[nativewater]

I had no luck finding a conversion for oz to rachel. The oz measurement is weight of a square yard of fabric in ounces. You can do conversions as appropriate to metric. Or you can weigh a fabric sample and calculate how much a square yard would weigh.

In any case, the material you want for your kayak is something roughly the weight of blue jean material.

[alphydan]

Anyusername, the conversion would be 270grams per square meter of fabric.
(1sq yard -> 0.836 sq meter)
(8oz -> 226 grams)

[anyusername]

Thanx a lot

[shilohjim]

The only part I'm not clear on is the stitching of the center seam. The instructions say it's a spiral stitch like a notebook but the pictures show a stitch that looks more like a back and forth stitch. Thanks for a great 'ible.

[nativewater]

the spiral stitch is a one pass and works well with synthectics. I haven't tried it with cotton.

[armored bore]

Would it be harmful to soak and dry cotton skin a second time?

[nativewater]

no.

[armored bore]

I'm assuming that if you decided to paint the skin for decorative purposes, that is done after it's been varnished?

And while I'm at it, what was traditionally used to seal the skin and make it watertight? In the photos I've seen, it looks like some kind of leather is used for the skin, so I'd guess they use some animal byproduct.

[aaervik]

Hey, I really like this instructable and am considering building this. I'm having a hard time finding appropriate fabric, though. Do you know if a 50/50 blend of cotton and nylon, an 8oz fabric, would be appropriate? It's called beaver nylon where I live, and it is a rugged material for sure.

[nativewater]

the stuff should work.  One of the pleasures of building a boat from scratch is personally finding out what works and what doesn't. I've used ten oz cotton in the past and this blend should be stronger.

[IMAsaltedPretzel]

Hey, I've been having a great time following your instructable and creating my own kayak.  I have, however, wandered from your plans a bit.  I am not a serious kayaker and rather decided to build an open-top kayak that is 14 feet long with a 23 inch beam so i may take some leisurely fishing trips in a nearby lake.  When applying my skin, would it be a horrible idea to simply stretch the fabric over the hull and use an air stapler to staple the fabric to the inside of the gunwales?  I really like the open top concept so i may be able to jump out and do a little swimming when it gets a toasty in the hull.  Thanks!

[nativewater]

Open top sounds like a good idea for your application, as does stapling the skin to the gunwales.  Enjoy. 

[movieman1500]

 If using heavy cotton fabric do I need to wet it down too

[balloondoggle]

This looks like a do-able father/son/daughter thing for us. I'm not reall clear on the deck lines though: What do they do, how are they installed? A bit of detail would be very helpful.

[attaboy]

is the combing attached in any way to the masik and backrest ? if so, How? also, what about the sides of the combing? are they attached to the gunwales? thanks much for the great instructions, you did an excellent job. Elmer Johnson

[nativewater]

the coaming is attached to the skin only but rests on the deck beams. There is no support at the sides except for the skin.

[Mike McGill]

This is a phenominal boat - most impressive. May I suggest that you turn this instructable into a book. I would be your first customer. Congratulations on the tradtional build. Great to see some heritage being saved.

[nativewater]

thanks for the favorable comment. yeah, the thought of turning this thing into a book has occurred to me. But I have another book to finish first, the second edition of The Aleutian Kayak. Writing the book isn't that time consuming. The killer is all the peripheral stuff like layout, doing illustrations, etc. I think I need to look for someone who wants to get some experience with In Design so I don't have to do the layout.

[dondonjordan]

could you use the same method using fibreglass resin? i'm aware it would change the weight completely

[nativewater]

A nylon skin impregnated with epoxy resin would be hard and brittle and not as strong as a flexible skin. You would have a weaker boat. There are two-part urethanes that are tough but flexible and some people use those instead of varnish.

[dondonjordan]

yeah that thought came to me at like 2 in the morning what I'm really looking at building is a canadian canoe that will carry 2 and camping gear to use on lakes and rivers here in ireland but something light like a greenland looks perfect for some light fishing and general fun and really easy to start with

[nativewater]

Here's a link to my web page where I feature a Canadian canoe.
http://www.wolfgangbrinck.com/boats/tales/ojibwaycanoe.html
When I finished it, it weighted 60 lbs. Once the wood dried out, it came down to 55 lbs. As I mentioned on the page, I would make the ribs flatter in the middle the next time, but other than that, no complaints. And when loaded down with gear, this boat would be pretty stable.

[luvit]

i made a wooden spoon like a viking.

[peerstrik]

Someone told me, and I think it makes sense, that since nylon is flexible you should use a flexible coating. If the nylon stretches beyond which the varnish can handle, the bond between fabric and varnish will break with a leak as a possible result. Therefore would an oilbased varnish like Tonkinois a good alternative since it is (possibly?) more flexible than a exterior polyurethane varnish?