Shrike, a lightweight sea kayak for home construction.^

Places, technique, kayaks, safety, the sea...
Spikeedog
Posts: 88
Joined: Wed Jun 28, 2017 6:51 pm
Has thanked: 163 times
Been thanked: 10 times

Re: Shrike, a lightweight sea kayak for home construction.^

Post by Spikeedog » Thu Sep 19, 2019 6:49 pm

I used a modified wooden egg cup and stainless steel rod mounted on a wooden plate that sits under the deck. Works and looks great.

User avatar
nickcrowhurst
Posts: 1164
Joined: Sun Aug 06, 2006 11:07 pm
Location: Cornwall, between swims.
Has thanked: 54 times
Been thanked: 89 times
Contact:

Re: Shrike, a lightweight sea kayak for home construction.^

Post by nickcrowhurst » Fri Sep 20, 2019 9:25 am

Oisin wrote:
Thu Sep 19, 2019 1:03 pm
The local 3d printing route hasn't worked so I've been looking at surfboard leash plugs, mock up in the pictures above. 20 of those are very inexpensive.

I can drill the hole with a forstner bit and have a backing plate under the deck I think
Oisin, that looks to be a good solution, provided it can be secured strongly. In a rough water capsize and wet exit, a single fitting would need to be strong enough to take a shock loading of the paddler's weight. How do you plan to strengthen the fitting against a high upward load? On a GRP surfboard one can laminate glass cloth and resin into the grooves below the surface. Would you plan to do this, or perhaps to insert small pieces of plywood to achieve the same object?
Thanks for the input.
Nick.

User avatar
nickcrowhurst
Posts: 1164
Joined: Sun Aug 06, 2006 11:07 pm
Location: Cornwall, between swims.
Has thanked: 54 times
Been thanked: 89 times
Contact:

Re: Shrike, a lightweight sea kayak for home construction.^

Post by nickcrowhurst » Fri Sep 20, 2019 9:31 am

Spikeedog wrote:
Thu Sep 19, 2019 6:49 pm
I used a modified wooden egg cup and stainless steel rod mounted on a wooden plate that sits under the deck. Works and looks great.
Spikeedog, that's a good solution. I guess beech is a suitable timber: https://bit.ly/2kW3cRE
Nick.

Spikeedog
Posts: 88
Joined: Wed Jun 28, 2017 6:51 pm
Has thanked: 163 times
Been thanked: 10 times

Re: Shrike, a lightweight sea kayak for home construction.^

Post by Spikeedog » Fri Sep 20, 2019 11:09 am

I think those were too small. The oned I used were about 3" wide but beech and a plywood Base plate with a good length of stainless steel rod to spread the load.

mcgruff
Posts: 112
Joined: Thu Dec 07, 2017 1:06 am
Location: Scotland
Has thanked: 29 times
Been thanked: 24 times

Re: Shrike, a lightweight sea kayak for home construction.^

Post by mcgruff » Fri Sep 20, 2019 7:52 pm

nickcrowhurst wrote:
Fri Sep 20, 2019 9:25 am
In a rough water capsize and wet exit, a single fitting would need to be strong enough to take a shock loading of the paddler's weight.
For hammock suspension, the rule is to use cord etc rated at least x5 the person's body weight to cover shock loading & any weakening from knots or splices.

Presumably a kayak leash (and fittings) would need to be at least this strong. There's the same inertial mass to accelerate plus the water resistance of the human sea anchor being dragged through the water.

User avatar
nickcrowhurst
Posts: 1164
Joined: Sun Aug 06, 2006 11:07 pm
Location: Cornwall, between swims.
Has thanked: 54 times
Been thanked: 89 times
Contact:

In Luxembourg.....

Post by nickcrowhurst » Fri Sep 27, 2019 3:40 pm

In Luxembourg, a young lady glasses the hull. This will be the second Shrike in her family.
Image

Beryl
Posts: 26
Joined: Fri Jan 11, 2019 9:51 pm
Has thanked: 26 times
Been thanked: 5 times

Re: Shrike, a lightweight sea kayak for home construction.^

Post by Beryl » Mon Sep 30, 2019 7:43 pm

On the subject of leash to attach kayaker to boat... I’ve been worrying this as most places on the Shrike are only 3mm thick. You could use the Masik I suppose but that puts the safety cord in your lap with possibility of entanglement. I’m thinking a solution might be an external cord attached to the stern. You have the solid wood of two gunwales, possibly already drilled for a lifting grip and the advantage that the dead weight of the kayak will not be side-on.
Growing old disgracefully

User avatar
nickcrowhurst
Posts: 1164
Joined: Sun Aug 06, 2006 11:07 pm
Location: Cornwall, between swims.
Has thanked: 54 times
Been thanked: 89 times
Contact:

Courses for Shrike building anywhere in the U.K

Post by nickcrowhurst » Mon Oct 21, 2019 2:35 pm

Chris at Selkie Kayaks has a novel idea. If you can get together a group of 4 to 8 fellow paddlers, and supply a suitable venue, he will supervise a 9 day course, at the end of which you can each go home with a completed Shrike for £1,000. That includes anywhere in the U.K: https://selkiekayaks.co.uk/9daycourse
There are initial plans for a series of such courses in Norway.

User avatar
nickcrowhurst
Posts: 1164
Joined: Sun Aug 06, 2006 11:07 pm
Location: Cornwall, between swims.
Has thanked: 54 times
Been thanked: 89 times
Contact:

A Shrike under construction in Italy

Post by nickcrowhurst » Mon Nov 04, 2019 9:49 am

Federico from near Turin, Italy, is making good progress:


Image

craigx
Posts: 1
Joined: Sat Nov 23, 2019 2:32 pm

Re: Shrike, a lightweight sea kayak for home construction.^

Post by craigx » Sat Nov 23, 2019 2:49 pm

downloaded the designs for these beautiful kayaks yesterday and spent the day reading the manuals. I really like to make one of these, but my garage is only 16 foot long. So i need to reduce the length to 15 foot somehow. What would be the consequence of doing this to the vember design by moving the First and last stations and minor adjustments to others. I am 185lb so need to keep the free board for the standard kayak. I prefer the shrike design but feel that alteration to this may be more problematic.
Anyway, thank you for the designs. It has been very thought provoking and given me a Good read.
Craig

User avatar
nickcrowhurst
Posts: 1164
Joined: Sun Aug 06, 2006 11:07 pm
Location: Cornwall, between swims.
Has thanked: 54 times
Been thanked: 89 times
Contact:

We need to talk....

Post by nickcrowhurst » Sat Nov 23, 2019 4:53 pm

Craig, I will need to do some calculations before advising you. Meanwhile you could use the PM system via the contact point to the right of each post to tell me a little more about your kayaking experience, type of paddling envisaged, etc.
Keeping all other variables constant,(which you can't), reducing length will reduce stability. Moving station points is a complex area, so we need to discuss this.
I'm very pleased that you are planning to build one of our designs. Shrike is of pure West Greenland heritage, exciting and responsive to every paddle stroke, while Vember is a Shrike with the sharp chines rounded off, giving a more steady stability curve.
Nick.

User avatar
nickcrowhurst
Posts: 1164
Joined: Sun Aug 06, 2006 11:07 pm
Location: Cornwall, between swims.
Has thanked: 54 times
Been thanked: 89 times
Contact:

Stefanos from Greece is making progress

Post by nickcrowhurst » Wed Nov 27, 2019 10:28 am

Smooth lines and good work from Stefanos in Greece. This is the 216th confirmed construction of a Shrike.


Image

Beryl
Posts: 26
Joined: Fri Jan 11, 2019 9:51 pm
Has thanked: 26 times
Been thanked: 5 times

Re: Shrike, a lightweight sea kayak for home construction.^

Post by Beryl » Wed Nov 27, 2019 8:25 pm

Nick, I’ve been thinking at some point of trying a sail on my Shrike. Could you put up some thoughts on this? I’m thinking it’s easier to do any mods as I build the boat even if it’s just a simple reinforcing strut under the deck for the sail base. Thanks.
Growing old disgracefully

User avatar
nickcrowhurst
Posts: 1164
Joined: Sun Aug 06, 2006 11:07 pm
Location: Cornwall, between swims.
Has thanked: 54 times
Been thanked: 89 times
Contact:

Re: Shrike, a lightweight sea kayak for home construction.^

Post by nickcrowhurst » Thu Nov 28, 2019 8:29 am

As you suggest, the only part of the sailing rig that cannot easily be fitted after the hull and deck are completed is a strut down from the mast step to the keel. In my case, I fitted a second skeg in the bow to improve windward performance, and the mast step is supported by the skeg box. To retro-fit the forward skeg box I installed a forward hatch just large enough to insert the skeg box. You could fit a forward hatch to enable a strut to be fitted. A reinforcing pad of plywood could also be fitted under the deck after dry-fitting the foredeck, but before gluing it in place.

Image

User avatar
nickcrowhurst
Posts: 1164
Joined: Sun Aug 06, 2006 11:07 pm
Location: Cornwall, between swims.
Has thanked: 54 times
Been thanked: 89 times
Contact:

Peter M's lunch stop on the Fowey River, Cornwall

Post by nickcrowhurst » Mon Dec 02, 2019 9:42 pm

Image

User avatar
nickcrowhurst
Posts: 1164
Joined: Sun Aug 06, 2006 11:07 pm
Location: Cornwall, between swims.
Has thanked: 54 times
Been thanked: 89 times
Contact:

David from Boston, USA, is building his Vember

Post by nickcrowhurst » Tue Dec 03, 2019 11:58 am

Image

User avatar
nickcrowhurst
Posts: 1164
Joined: Sun Aug 06, 2006 11:07 pm
Location: Cornwall, between swims.
Has thanked: 54 times
Been thanked: 89 times
Contact:

Alec from Romania with more original variations on Vember.

Post by nickcrowhurst » Fri Dec 06, 2019 10:55 am

Alec Naneti from Romania already has a foam 3-part Shrike in our Gallery: https://cnckayaks.com/2017/12/14/alec-n ... m-romania/
He has now applied his skills and original thinking to use cheap foam to build for a child a 75% scale round-bilge Vember in strip foam, and then to make it 3-part:

Image

https://photos.google.com/share/AF1QipO ... 82eGJlR1dR

Post Reply