Folding Kayaks Forum

The user forum for FoldingKayaks.org
It is currently Thu Jan 18, 2018 9:45 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 23 posts ]  Go to page Previous  1, 2
Author Message
PostPosted: Sat Sep 10, 2016 8:06 pm 
knight of the folding kayak realm
User avatar

Joined: Fri Sep 25, 2009 10:46 am
Posts: 465
Location: inland Pennsylvania, USA
Two-part polyurethane coatings on fabric are stable and don't give off any chemicals into the environment, especially in water as nothing about the compound is water soluble. I can't think of another coating that would be as durable and non-toxic.

_________________
Current:
Feathercraft Wisper
Pakboat Quest 135
Pakboat Puffin 12
Pakboat Swift 14
Greenland SOF
P & H Easky 15LV
Previous:
Feathercraft Kahuna
Feathercraft K-1 Expedition
Pakboat XT-15


Top
 Profile  
 
PostPosted: Fri Sep 16, 2016 10:46 am 
faltbootemeister

Joined: Tue Feb 05, 2013 1:15 pm
Posts: 109
Kerry,

Couldn't pass on this topic without saying that your Greenland kayak might be the most beautiful kayak I've ever seen. It must be a joy to paddle for a number of reasons.


Top
 Profile  
 
PostPosted: Fri Sep 30, 2016 6:03 am 
forum fan

Joined: Fri Aug 19, 2016 6:39 am
Posts: 17
KerryOnKayaks!,
what exactly should I ask for/look for, if I want to purchase the soft, strong, adhesive, waterproof polyurethane 'coating' that I want to put on top of of my ballistic nylon?


CarstenT

EDIT:
an aside:
It turns out that my ballistic nylon shrunk in the neighbourhood of 10% (10 PROCENT!) after giving it a 60¤ wash and dry-tumbling - like I do my own clothes. Before washing I asked the firm. Guess what: "we don't know". That would be the shortest path to get rid of customers ;o/


Top
 Profile  
 
PostPosted: Sat Oct 01, 2016 10:04 pm 
knight of the folding kayak realm
User avatar

Joined: Fri Sep 25, 2009 10:46 am
Posts: 465
Location: inland Pennsylvania, USA
The Skin Boat store sells the 2-part urethane that was used on my boat:

http://shop.skinboats.com/2-part-Urethane-System_c5.htm

Thanks for the compliments on my boat ("Sisiutl"). She is, indeed, a magical boat to paddle for many reasons. She was built by Lodro Dawa, an American Buddhist monk in Oregon who used to make custom skin on frame kayaks under the name "Monkcraft". The green-dyed translucent skin glows in the sunlight like a piece of jade and the very refined design is fast and glides and tracks like an arrow. She handles rough water very well.

The stats are 18' 2" long, 20" wide and 31 lbs. The boat is extremely comfortable to paddle -- has a Snapdragon backband and I sit directly on the inside of the hull on a folded over half sheet of 1/2" Ensolite closed cell foam (my old backpacking sleeping mat) and it has adjustable foot pegs. I've never felt cramped or uncomfortable in the boat, even on all-day paddles.

The boat is a copy of a native made seal hunting kayak surveyed in Sisimuit, Greenland, in 1935. Skin on frame guru and designer Brian Schulz describes this model in his older blog site and says it is one of his favorite traditional designs to build. Lodro somewhat modified the built-in skeg dip in the keel line.

http://capefalconkayak.com/1935sisimuit.html

By the way, the nylon will stretch a bit when wet before it is coated. I think the usual process is to soak it before stitching it over the frame, then it will tighten up as it dries. Once it's coated it will stabilize and no longer stretch or sag. Mine was built 9 years ago and is still in great shape despite a lot of usage. All I have done in the way of maintenance is recoat parts of the main stitched seam with Aqua-Seal and treated the exposed wooden parts of the cockpit coaming and the floor with a wax-based wood "feed" and restorer.

_________________
Current:
Feathercraft Wisper
Pakboat Quest 135
Pakboat Puffin 12
Pakboat Swift 14
Greenland SOF
P & H Easky 15LV
Previous:
Feathercraft Kahuna
Feathercraft K-1 Expedition
Pakboat XT-15


Top
 Profile  
 
PostPosted: Sat Jan 28, 2017 4:06 pm 
forum fanatic

Joined: Mon Apr 13, 2015 2:10 pm
Posts: 54
I'd stay away from nylon because it stretches and shrinks too much. In my opinion, polyester is a better bet unless you have a frame that is adjustable.
Liquid coatings on uncoated material may make the material waterproof, but it may not get you much abrasion resistance. It also may not age well. PVC coated polyester works well. It is rugged and the material should last well over 10 years. Even 20 year old PVC boats are still in good shape. Another important point is that good contact adhesives for PVC are easy to find. This is important both for the initial build and for later field repairs.


Top
 Profile  
 
PostPosted: Sat Jan 28, 2017 6:59 pm 
knight of the folding kayak realm
User avatar

Joined: Fri Sep 25, 2009 10:46 am
Posts: 465
Location: inland Pennsylvania, USA
I beg to defer with your contention that the nylon coatings are not abrasion resistant. I've had my urethane coated nylon SOF for going on 9 years and have subjected it to all sorts of dragging, scraping and battering. The rubbery, flexible skin doesn't easily abrade at all. I would refer you to videos of people attempting to destroy nylon/urethane skins if you want an example of durability.

https://www.youtube.com/watch?v=gYyvIExWkqU

https://www.youtube.com/watch?v=3Xb_21OLjHE

_________________
Current:
Feathercraft Wisper
Pakboat Quest 135
Pakboat Puffin 12
Pakboat Swift 14
Greenland SOF
P & H Easky 15LV
Previous:
Feathercraft Kahuna
Feathercraft K-1 Expedition
Pakboat XT-15


Top
 Profile  
 
PostPosted: Sat Jan 28, 2017 8:11 pm 
lord high faltbotmeister

Joined: Fri Oct 07, 2011 1:51 pm
Posts: 602
Location: Colombo, Sri Lanka
Talking about SOF polyurethane-coated nylon, my experience hasn't been all positive, but it may be a design issue. It is a tough material with very high impact resistance, but it's also quite rigid and (this is purely speculative) perhaps not as slippery as PVC; where the frame touches the skin in high-wear areas (keel and chines)on my SOF F1, I've had a few issues with abrasion, especially along the edges of the wooden spars. Until I covered the superficial damage with Aquaseal, this meant that some water did get in. I'm not saying PVC is perfect but the issues I've had over the year have tended to be more from sharp objects cutting the PVC. But then I do tend to take more care of my folders than my F1 8)

_________________
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


Top
 Profile  
 
PostPosted: Sun Jan 29, 2017 1:10 pm 
forum fanatic

Joined: Mon Apr 13, 2015 2:10 pm
Posts: 54
Dimensional stability and tear strength are taken care of by the substrate (nylon, cotton, polyester etc.). Waterproofness and abrasion resistance by the coating (hypalon, PVC, TPU). Abrasion on a "skin on frame" kayak or canoe hull is almost always concentrated where the skin is in contact with the frame. That is why we add coating by installing keel strips. Another very effective way to protect the skin from abrasion is to insert closed cell foam between skin and frame. We do this on all expedition grade canoes that are expected to be exposed to severe abrasion. But foam is bulky and does not pack very well, so it is not used much in kayaks that are not usually abraded all that much. However, the foam is effective. If you want to try it, we have found that 1/4" of medium density (about 4 pounds/cu.ft.) works well. This is based on 20 years of experience, and we have installed it in over 2000 canoes.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 23 posts ]  Go to page Previous  1, 2

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group