Cooper Mind-numbing Details

This post is for the technogeeks. Read the prior post for general info on the new Cooper.

Before I begin this diatribe, I very much want to thank those who contributed to the development of the Cooper. I’ve bounced ideas off of Cliffy till he’s black and blue, and he’s always full of his own. AnnD and Bob K also viewed and paddled an early prototype and provided valuable critiques. Gobe raised our confidence level by placing an immediate order after seeing the prototype which was not nearly as pretty as the final version. And all past and present customers have contributed much more than you will ever know by posting comments, writing letters and generally telling us what you do and don’t like. A heartfelt thanks to you all.

I have tried to organize my thoughts with regard to the reasons for the Cooper prior to writing this so it won’t be too disjointed, probably to no avail.

First and foremost was the tensioning system. All of our boats to date have used a scissor-type frame expansion method as have some others. Klepper developed it first. Lots of force can be exerted this way…necessary to stretch the boat skin lengthwise and put the frame in compression. It’s a great system for holding everything together, but the long arms of the scissors require a large, open cockpit. Restricting the size of the cockpit can make assembly very difficult. Goal #1 was to develop a method that didn’t involve the cockpit, and as many as ten years ago, we were experimenting with inflatable bags between two solid bulkheads, eccentric cams, etc. Other folding boats use ropes and pulleys or jacks to tug the hull fabric over the stern end, but the results are barely OK, if that. I wanted a system that was simple, lightweight, adjustable, and able to generate quite a bit of outward force. Basically, we wound up with a screw jack that moves only the stern keel end. 3/4″ acme threaded rod at 6 turns/inch in nylon puts roughly 1/2″ inch of material in shear which is more than adequate to support over 400 lbs. of outward thrust. The handwheel was designed and molded for us to eliminate the need for tools. Access to the handwheel is through the rear zipper which is not closed until the skin is tightened. The inevitable slight shrinkage that occurs with all fabrics over the years should no longer be a problem. Finding a system that we were happy with was a major hurdle finally overcome. Now that cockpit restrictions were relieved, the fun could begin on goal #2 which was a lightweight but robust boat.

.75 dia., .035 wall drawn and anodized tubing has proved itself for over 30 years, so we stuck with that for the longerons. Each set, bow to stern, is shock-corded together so that the assembly procedure is not the equivalent of a jigsaw puzzle. There are 5 crossframes made of black anodized .720 dia., .060 wall drawn tubing with a 6th tiny oval of the same material at the stern to stablize the jacking mechanism so that it pushes straight back rather than trying to kick off to one side or the other. Longerons snap into half-moon clips permanently mounted to the frames. There are locator clips all along the longerons showing proper frame position and to prevent any forward or aft movement after assembly. The two sets of locator clips shown are for different set-up postitions depending on the paddler’s height. The cockpit frame is also anodized aluminum and measures about 38″ X 18″ and is swept up, at both ends, more pointed at the bow. The deck fabric, of course, is trapped side-to-side as it traverses from bow to stern, except for the cockpit opening. Most folding boats use extra components here which are tedious to assemble. We found that 2″ Velcro flaps sewn along the fabric cockpit edge and wrapped around the cockpit frame worked well, as long the Velcro to which it mated was spiraled around the frame and riveted down at each end to eliminate adhesive creep. It works like a charm no matter how hot it gets, and the shear of 2″ hook and loop wrapped around a tube can’t be beaten. The cockpit coaming is a soft coaming similar to the Edisto but with a rigid frame inside the closed cell foam to hold a spray deck securely. The padded but internally rigid coaming also makes it easier to get in and out of the Cooper, as we all like to use the coaming for support. The complete frame weighs in at about 15 lbs. Of course, no tools are required for assembly.

The hull fabric on a folding boat has always been of great interest to us. The boat skin is usually the single heaviest component by a big margin. The internal fabric, or substrate, is critical in terms of tensile, tear, and ball burst strength. And adhesion of the coating to the substrate is equally important. What has never been important to me is the thickness of the coating, whether it be Hypalon, neoprene, urethane or PVC, except in the mind of the consumer, which trumps all other reasoning. There is a new folding boat on the market that uses a hull fabric with no substrate, which I think is dangerous. On the Cooper, we selected a lighter fabric, but one that uses the same substrate, 1000 denier woven polyester, as our hull fabrics of the past. This is risky from a consumer perception standpoint, but not from a safety or durability standpoint. The TPU coating is a blend of urethane and PVC, making it very abrasion resistant, but also quite easy to permanently patch.

Deck fabric remains the same as we have used for many years: woven polyester with a urethane back-coating to waterproof. We would have choosen a lighter nylon fabric, but nylon is quite hydrophilic and expands so much when exposed to moisture that a loose and sloppy deck results.

Small details have been attended to as well, such as storm flaps that fold back at the ends to keep zipper pulls from getting lost under them, clean and simple joints where the longerons connect to the keel end with no parts to lose, and painter loops at bow and stern sewn in. Sponson pockets are larger and made of a mesh fabric because of its weight and because the sponsons are also totally new and so handsome, we wanted you to see them.

All boats will automatically come with foot pegs and standard safety bladders, but we now offer oversize safety bladders that literally fill the boat forward of the paddler’s feet and aft of the seat.

One person described a test paddle in the Cooper as similar to getting a big hug, not because he was squeezed into the cockpit, but because of the rounded edges, padded coaming and comfortable seat. It’s a very friendly feeling boat.

I know there will be other questions. 800.533.5099 will get you the answers.


10 thoughts on “Cooper Mind-numbing Details

  1. Phil, what great attention to detail: full length, fully exposed zippers; securing frames using locator clips instead of fingertip-nicking keyholes; built-in line loops both fore and aft (I’m in the process of adding aft line loops to my Aleut and GII, to keep the rudder assembly free); perfect fitting safety bladders available from the factory; padded edges all around the cockpit; backpack carrying back (make sure it has well padded straps and is properly balanced, please!). Excellent work, sir.

    The Cooper is a great design and great deal compared to its prime competitors from Feathercraft and Firstlight (and the hardshells). I look forward to placing an order for one this summer.

    Keep up the good work, sir (and please start work on the double version, as my GII is tough on my back!).

    John G.
    La Jolla, CA

  2. Wow, the more I see of this boat the more I want one. It’s not a matter of if I’m going to get one, just when (and what color).

    Thanks for listening to us all and building a great boat for us.


  3. Beautiful!

    You and the folks at the factory have every right to be proud! When I saw the first pictures posted, it looked like the Feathercraft Bob brought to the Flamingo 2003 (yellow and black). The sharp bow & stern, the slim profile … I was not prepared for such a departure from current Folbot outlines. Simply amazing. I agree with some of the other opinions on the forum – you folks are going to be hard pressed to keep up with orders when word of this gets out. You have definitely earned bragging rights too! The innovations you have implemented in this model are numerous.

    Well done Folbot!


  4. Nice design! I’ve always said I wanted a boat that paddled like my F-craft K-1, but was as economical and easy to assemble as my Aleut. And I’m really glad to see Folbot supplying those big bow and stern filling flotation bags.

    Some have commented in Bagboaters about that nylon screw as a potential failure point; I assume the material was chosen for it self-lubriucating properties, ease of machining and light weight, right? I’m wondering if you looked at other materials, like glass filled nylon.

    I just introduced yet another hard shell paddling friend to folders; she has a polyethelene boat that she keeps up North, at her cottage, as she drives a company car and can’t put a roof rack on it. She liked the Aleut but asked me if there wasn’t a longer, narrower boat that assembled as quickly. I suspect a lot of paddlers feel that way.

  5. Outstanding engineering job. With that method of securing frames in position, it is really easy to get fair lines, and the light weight as a bonus.

    That jackscrew is inspired — and the linchpin of hull tautness. Concerns about it are natural. Mine is: can it work its way looser, or is there a locking feature?

    Congratulations on a leap forward for folding boats.

  6. Mr. Phil,
    Thank you for all the techo info. Us engineering types love the details. The expansion assembly is the perfect squelch to an annoying problem. I bet that method will show up on “other” folders. The acme thread (used in most vise screws) should hold up in all circumstances. I guess I better order a Cooper soon, before the lead time is 10 months!

  7. Thanks for some good questions. We did look at glass filled nylon but the shear strenth of the Acme threads on the Type 6 nylon rod and 3/4″ hub is about 5700 lbs. (So that the engineers can check me, that’s .5625 rod I.D. X 3.14159 X 4.5 turns X .080 X 9000 psi.) We haven’t been able to detect any handwheel creep after giving the boat a pretty good workout, but we are ready to supply a second handwheel for a jam lock should it occur. We really appreciate everyones’ interest!


  8. At last a really great looking performance type boat from Folbot that is light enough for some of us older set with busted backs. I have an Aleut but have never been too happy with it. Sort of eyed up a Kodiak but the weight always seemed a problem. I have a couple of Seda hardshells and recently acquired a folding boat from China- the Atlatl- it is not as well made as a Folbot but it’s okay for a smaller person and I plan of giving it as a present to my grandson to introduce him to kayaking now that I am getting a Cooper. Oh yes, I forgot to mention – I bought one in red. Figure I beat the summer rush.

    Gil (Seahorse) Muller

  9. All the engineering aside..
    This is a “pretty boat”.. This is a “Friendly” boat… This is a “Comfortable” boat..
    It’s ease of assembly.. along with the other “glad I got it” features.. make this a “gotta have” boat..
    Enough “quotes”…
    Kudos Mr. Phil………!!!!
    (Kudos.. ref: Websters New World Dictionary =.. Credit for an achievement; Glory; Fame)

  10. As a Mechanical Engineer with a machinist background, I could have vouched for that screw jack before PC posted all that engineering mumbo-jumbo. A 3/4″ piece of Acme threaded Nylon is pretty substantial, don’t be fooled by the “plastic is bad” mythology that some purport. My question is where can I get some of that hull material for my own homemade SOF kayak?


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