Z-boat conversion

[sbroam]

Z-boat conversion
by Daniel Holzman
I posted a few pictures on the Community Webshots website of my Z boat conversion. The address is

http://community.webshots.com/album/45256133OwjzTm

I made the plastic tube which is the most important piece in the conversion out of 1/4 inch PVC sheet plastic, put together using Harvey's PVC cement. The tube is rectangular in cross section, and is designed to be slghtly larger than the cutout on the front and back foam pillars which come with the Z boat. I think most plastic kayaks these days have front and back foam pillars, hence this approach should work on any similar boat. The tube is about 5 inches longer than the distance between the front and rear pillars, and is bolted into the pillars using galvanized steel nuts and bolts (stainless would probably be better, but expensive).

The thigh straps are attached to the two bolts which hold the kayak seat in place near the hips. The Z boat came with a brass plate which I used to hold the webbing in place (the webbing wraps around the plate). Using this method, there is no need to drill any additional holes in the boat, so if you ever want to convert it back to a kayak, you can.

I use a single large D-ring to hold both thigh straps down near the knees, but you could use separate D-rings if you wanted to. The D-rings are bolted through the top plastic plate, using double nutting underneath, since once the plastic tube is installed, you cannot get it out without extreme pressure, which would probably damage the foam pillars.

The seat is attached to the plastic tube using industrial velcro, which allows the seat to be adjusted after installation. I was lucky, the seat seemed to be in the right place when I put it in, but I could easily see where you might want to move the seat an inch or two in either direction, depending on whether you wanted the boat to be stern or bow weighted. You can see a little bit of velcro protruding beyond the front of the seat in the top view photo.

Total cost of conversion was less than $100, including minicell foam for the seat, the D-ring, the tube plastic and glue, seat belt webbing, two buckles, some elastic cord for the webbing quick release, two knee cups, two ankle blocks, and some glue.


Posted on Jul 29, 2002, 6:02 PM


nice engineering
by trevor bradian
where do you get the 1/4 inch pvc plastic & cement? i especially like the velcro idea. does it bond pretty well to the pvc & the minicell?


Posted on Jul 29, 2002, 7:14 PM



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PVC products
by Daniel Holzman
I got the PVC sheet at a local plastic supply house. I bought a sheet about 36" wide by 72" long, and cut the strips I needed to size on my table saw. PVC cement is available at any hardware store. Since you will be totally dependent on the strength of the tube, I suggest you glue the tube together using careful procedures, which means cleaning the PVC first with a commercial plastic cleaner (mostly acetone), then priming with a special PVC primer (the stuff I used was the purple Harvey's), then finishing the job with PVC cement. It sounds harder than it is, the stuff glues together in less than 60 seconds, and hardens overnight. The joint will be very strong and should be essentially permanent.

In order to strengthen the tube, I attached small cross pieces inside the tube every 6 inches or so. This allowed me to make a three sided box, no bottom. You will find that using a bottom is a royal pain, since the bottom piece will not conform to your hull, and it will be virtually impossible to slip a four sided square into the front and rear foam pillars, whereas a three sided box slides in easily. I then bolted the plastic through the pillars front and rear, making for a very secure setup.


Posted on Jul 30, 2002, 12:44 PM



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Square plastic tubes
by Silent Bob
Nice job on the outfitting. I was poking around Home Depot the other day and found square tubes like that ready made in the form of plastic fence posts. They were roughly 4x4 and about 1/4" thick. In case anyone else wants to use this method.

-Bob


Posted on Jul 30, 2002, 4:54 AM



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tubes
by trevor bradian
i've seen the tubes you're referring to, & had similar thoughts. it looks like with a few tools you could install a decent beam & build your saddle around it. possibly even use some velcro like daniel did to have the saddle adjustable.


Posted on Aug 1, 2002, 2:11 PM



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Vinyl Downspout
by Scott B.
Over with the plastic rain guttering I found vinyl down spout, about 2 3/8" square. I think it is plenty stiff enough. I think Jamie Dors has used that in a boat, but he reinforced the beam internally with plywood.

Another thing I'm thinking of trying is aluminum angle - I think two pieces of the 1/8" x 1 1/2" x 1 1/2" stock, spaced as far apart as the walls are thick, secured to a plastic base on the bottom, and then secured to the bow and stern walls with some sort of plastic "flanges". Lower thigh strap anchors would be bolted to the aluminum, the pedestal could be held down with webbing/buckles. I might just rework my Score's outfitting....

I've seen two other boats with aluminum outfitting that I wish I had taken pictures of - one was an aluminum "roll cage" in a Prijon Rockit, the structure was welded and more than compensated for the strength lost when excising the kayak seat. The other was a completely adjustable open boat pedestal in an NOC intructional boat - it could be adjusted up and down, fore and aft.

Scott


Posted on Aug 3, 2002, 11:26 AM



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