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Thread: Cataraft Frame and Floor Suggestions

  1. #1

    Default Cataraft Frame and Floor Suggestions

    Ok guys, I have looked at every website that I can find for different frames and floor layouts for a cataraft. I still have not found what I am looking for. I want to build my own frame, and floor.

    What I have for tubes are 16 foot, double tube Argronauts. They are hypalon/neopreme, and yes they are huge.

    In regards to the frame have seen lots of suggestions about using top rail from chain link fence. I wonder about the strength and if that is stiff enough? The aluminum pipe that NRS sells is not as light as I expected. Also, do I need to run a rail length-wise down each tube or could I get by just on the outside tube. I want a frame that I can break down and ship USPS. Any suggestions, ideas, or websites would be appreciated.

    Secondly, looking for some breakdown oars that would handle this beast. Have had no luck finding anything.

    Finally, the floor considering cutting up an old trampoline and sewing it up to lace in. Which brings up another question on the frame, what do I need to do if I have a flexible floor.

    Thanks for any suggestions, tips or pictures you guys canprovide. I know there are a lot of knowledgable people that lurk here and I am looking for any ideas, especially the cheap ones.

  2. #2
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    Default

    By "double tube" I assume you mean two on each side like the Aire Cougar. What is the diameter of the tubes? The Cougar has 18" diameter tubes, which are fairly narrow by cataraft standards, but with two on each side that makes them 36" wide. Leaving the normal 2' between the pairs makes the boat a full 8' wide. I modified my frame to have only an 18" gap in the middle, as there is a slot in Sixmile that is very tight for an 8' wide boat.

    The frame I use has the side rails a little wider than the center of the outer tubes. This makes my frame not quite 6.5' wide for my 7.5' boat. There are three cross bars from these rails, one on each end and another for the seat. Connected to the two end bars are two bent/drop rails paralleling the outside rails, and running along the insides of the gap between the tube pairs. These rails are bent at both ends to drop down about six inches, and hold the tubes apart. There is an 18" cross bar going between these inner rails that is used for a foot bar. You need something low on the inside holding these tubes in place. I don't think just going with outer pipes will do it. I also have an uncnnected cargo extention, but this is made from dimentional lumber instead of pipe. Oddly, I have found this a tougher combination than the usual connected pipe cargo modual, because it allows the boat to flex without twisting a long frame.

    I'm using NRS LowPro fittings, and everything is adjustable. You could do the same with Halleander style Speed Rail fitting if you want, but it's not much cheaper. I'm using 1.25" anodized aluminum schedule 40 pipe with an external diameter of 1.66" If you went with the Speedrail style fittings you could use larger 1.5" schedule 40, or even schedule 80 (thicker walls), but I would not use lesser pipe.

    I have used galvanized fence pipe for a few pieces, and the NRS fittings will work with it, but it is not nearly as strong. I've bent it up pretty bad. For low stress areas it can work, but if you whack a rock with it, it bends fairly easy. I don't think it's any lighter, but it does cost less. Lots of boat frames are made with galvanized pipe, but I don't think it's a good choice for catarafts. Ak Steel sells 1.25" anodized pipe for $84 for a 20' stick. It adds up fast.

    Here's NRS's cat frames: http://www.nrsweb.com/shop/product_list.asp?deptid=1053

    Personally, I like Alaska Raft & Kayak frames better for breakdown: http://www.alaskaraftandkayak.com/in...d=17&Itemid=12

    Depending on the width of the frame you should be able to use 10' oars with it, and Carlisle makes 10' breakdown shafts. One thing I have done, is to take standard NRS oar uprights, and reverse them to have them closer in on the sides. This brings the oarlocks (or pins) in about 5-6 inches closer on each side, while still maintaining the normal 15 degree outward cant, and this allows for shorter than normal oars. I use 9' oars on my Cougar this way, and if your boat is wider than 8', you should still be able to use 10' breakdown oars. BTW, I much prefer this setup to the usual method of mounting, and the uprights don't take near the beating this way, as they are completely inboard of the tubes. Alternatively you can use 10' breakdown shafts and 1' extenders to create 11' breakdown shafts.

    The trampoline floor material might be fine, I don't know. Other than being tough, it needs to be pourous to let the water drain out. Otherwise, just use a lot of gromets and lace it onto the pipe rails. Or you can get fancy and lace it on to some thin secondary side rails, and strap those onto the pipes when you want to add the floor.

  3. #3

    Default Thanks Jim, Great Info.

    Jim,

    Thats what I mean by double tubes, each tube is 18". The frame I have now is 6' wide. On the frame that I have now it has one rail running down the center of the outside tubes, and a rail running down the center of the inside tubes. I have a plywood floor that laces into grommets that are attached to the inside of the tubes. There is a long heavy piece with grommets that run down the inside of each tube.

    I appreciate the help Jim, I will post a picture tonight or tomorrow showing what I have and see what you think of it, and how I can improve, lighten it up, store what I need, and still keep it stable.

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    Question cataraft .....

    This thread belongs in the Alaska Rafting Forum, right, Moderator?

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    Moderator Alaskacanoe's Avatar
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    Smile Inflatables

    I know what you mean Rick, but I was kinda enjoying the talk about frames for Catarafts for a different reason,..
    I have strapped two canoes together inorder to haul out a moose and all our gear in one easy move.. ( Using Alder poles )
    Jim S has considerable experience in doing just this same thing with two inflatable Kayaks, and making an expedition boat out of it..
    Jim has done some pretty amazing things using the resources he has at hand, instead of just reaching for his wallet.. He finds a way to make things work for the given application, and so I sat back to see if he would post a picture or two of his two kayakaraft set up...

    I make a lot of frames each season for many people down here on the kenai. I bought a pipe bender that uses a hydrolic ram. This year I am behind the curve on getting frames built. It will be the middle of July before I get caught up...
    Anyway, We can move this to the Rafting forum if you like..
    Max
    When you come to a fork in the trail, take it!

    Rentals for Canoes, Kayaks, Rafts, boats serving the Kenai canoe trail system and the Kenai river for over 15 years. www.alaskacanoetrips.com

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    Default 2 canoes tied together.

    If the discussion is tying 2 canoe together, I started doing that last season.

    Rather than alders, I have made a "frame" from 2 pieces of rectangular 6065 tubing - 2" x 1", that are about 8' long, clamped to the gunwales with 8 square U-bolt clamps (AIH) and some "washers" made from aluminum angle. The lashing bars allow me to run my 19'er and my Wenonah 16' Kingfisher side by side, cataraft fashion, with expanded freight capacity, under power. The only flaw has been the spray that comes from the Wenonah into the Grumman. So, this season, I'm rigging a spray cover (3/8" plywood or a tarp) between the 2 lashing bars to keep the spray from getting in the Grumman.

    So, that's my cata-canoe frame, and I like it. The second canoe serve as added cargo capacity, adds amazing stability, and when separated, permits a capacity for exploration for which the motorized 19'er is unsuited. I like to explore the little creeks and ponds off the river. Further, I plan, where appropriate, to use the Wenonah as a sled to ferry moose meat back to the river. I've experimented with my Royalex Wenonah, loaded with gear, and it pulls very easily with approximately 150#. A moose quarter should be an appropriate load.

    I've thought about buying a second 19'er for my cata-canoe; then the hydrodynamics would be improved and the cargo capacity would be tremendous.

  7. #7
    Moderator Alaskacanoe's Avatar
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    Default Matching canoes

    I am sure having matching canoes would make it a better craft, but then it would not be in true Alaskan fashion .. me thinks....lol
    Max
    When you come to a fork in the trail, take it!

    Rentals for Canoes, Kayaks, Rafts, boats serving the Kenai canoe trail system and the Kenai river for over 15 years. www.alaskacanoetrips.com

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    Default

    Sorry for not keeping up, I've been on the Kennecott/Nizina/Chitna/Copper for the last 11 days. Really great trip!

    Here's a thread with pictures of my cata-IK frame & boats. http://forums.outdoorsdirectory.com/...ad.php?t=19864 I actually have two Aire Lynx IKs that this was designed for, but for a trip on the Fortymile one of them was being used by a fellow paddler, so I put Thrillseeker on one side. The T-Seeker is a fine boat but not nearly as comfortable for the long haul. Truth is, I can hardly tell the difference either way. The thread has pictures of the two Aire boats tied together as well as one with the T-Seeker on one side. The seat is just an old stack chair that had broken legs, and now has had the seat back cut off shorter than normal. If I did this frame over I would just cut a 3/4" piece of plywood to fit.

    I have one of those 9' pontoon fishing boats as well, but the twin IK rig is lower & far more stable. It also has extra packing space for gear.

    I suspect that two canoes of differing sizes would still work just as the two different IKs do. Obviously a matched pair would be a preferable rig, but shouldn't be needed for most uses.

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