Oct 25, 2009 at 3:10 pm #1240565
@vickrhinesLocale: Central Texas
Has anyone tried to MYOG a pack raft?
I've played with ideas, but have not put scissors to fabric.
Concept 1: uncoated pack cloth shell with oversized mylar, polyurethane, or cuben bladders.
Concept 2: Single-walled of Cuben or heat-sealable nylon.
Design ideas: Conventional oval – glorified inner tube; cat-raft with either solid or inflatable frame.
Any ideas? Successes you aren't telling us about?Oct 25, 2009 at 7:18 pm #1539638
I haven't tried anything yet. One idea my brother and I tossed around was buying a Seyvler trail boat and trying to glue some tougher nylon material too the bottom and sides to add durability where there are most likely to be problems.Oct 25, 2009 at 7:58 pm #1539653
W I S N E R !BPL Member
Same thing I've been thinking- experimenting with sewing a cordura or 1.9 oz. cover for the trail boat.Oct 27, 2009 at 1:15 pm #1540160
Jan RezacBPL Member
@zkoumalLocale: Prague, CZ
I was also thinking about making a raft out of a thin heat sealable nylon. I tried sealing samples of the fabrics and found that it won't be as easy as it seems: The coating does not stick well to the uncoated side of the fabrics, and it can not be glued either, because the thermoplastic PU used on the fabrics does not bond with glues for a normal PU. As a result, it would be needed to design it in a way where there are only seams that go coating to coating, and although it might be possible, it won't be easy. Either gluing or sewing and taping some other material would require less work.Oct 27, 2009 at 2:04 pm #1540176
I can't remember where I saw the photo now, but I think it was on one of the fabric sales sites… a skin canoe built out of what looks like tubular aluminum, the skin made of heat-sealable nylon… seems like you could scale something like that down? Downside of a more rigid hull would be rocks–more tearing over than bouncing off, potentially. Interesting…Oct 27, 2009 at 2:42 pm #1540190
I think I could do this out of heat sealable nylon. I know what a pack raft is but how big would you want something like this?Oct 27, 2009 at 4:23 pm #1540222
Bender are you refering to the canoe idea or actually making a raft? If anyone gets this going I'd love to hear about it. By the way what did you think of the idea of taking a rubber boat and putting a nylone cover on the bottom? I could see some complications but its seems doable.Oct 27, 2009 at 5:51 pm #1540251
Luke I was thinking I could actually make a raft.Oct 27, 2009 at 8:03 pm #1540292
Steve ParrBPL Member
@srparrLocale: SE Michigan
This thread (and the duct tape boat on a recent Mythbusters episode) have made me rethink the concept of an inflatable packraft.
Something like a traditional coracle or similar SOF (Skin On Frame) boat would be sufficient if not running whitewater. Maybe a urethane coated tarp over a lightweight PVC frame? How much framing would be needed if drybags (holding gear) were used in the bow/stern and an inflatable sleep pad in the bottom?
Google turned up this website (www.shelter-systems.com/kayak.html) that does a good job showing the general idea. To be a packable, it should be lighter (under 5 lbs? 10 lbs?) and capable of being assembled/disassembled/re-assembled at various locations.Oct 27, 2009 at 8:24 pm #1540306
Bender – I'd love to hear more about how you would go abot that. Sounds cool. At the moment I too poor to try anything but long term I would like to get a packraft type boat. Are you planning on attempting one? If you do I think a lot of folks would love to hear about it (and some might buy one from you).
Steve – I remember a do it yourself website that had a very lightweight canoe kit. It wasn't quit backpackable but I wonder if it could be modified. The Folding Kayaks Manuel is another place that cool to check out.Oct 27, 2009 at 8:52 pm #1540316
I would consider making one if someone really wanted it. I have no real use for it myself. I would also need a lot of input as to exactly what they wanted because I know little about rafts. 58-60" wide material is wide enough for a simplified version. I have material wide enough actually. Is the bow upturn absolutely necessary?
I think something similar to this is possible.Oct 28, 2009 at 1:35 pm #1540518
Alpo KuusistoBPL Member
I have made 3 packrafts, named from now on one, two, three.
All are self bailing, you sit above waterlevel. Next project will be more like Alpackas. They probably know best what works well.
Number one is 2 pound oversized swimming matress made for adventure races. Shell is sewn of tent fabric, with polyethylene inner tubes. (and computer fan inflation, extra half pound)
This is really fragile solution of course. Thin polyethylene is luckily easy to repair with duct tape. And it is available in tubular form in various diameters, which makes things so easy. However, for repair you need to deflate, remove inner tube, patch and inflate. If I had Bender's skill and equipment I'd try single wall.
Two and three are glued together of 250g/sq.m. PVC coated nylon bringing weight to 3-4 kilos. Material is already tough enough to paddle over river rocks, as long as they are not too sharp. Repair requires soft PVC specific glue and some cure time. Or lots of duct tape (the black stuff in the photo). I'd love to have some better material.
Both were long and built with little down curvature (anti rocker) in frame, which would then under my weight straighten. This worked well.
Number two was 4m long trimaran with 1,5 foot thick central tube you sit on, and small pontoons about 1 meter left and right. Reasonably fast, dry sit position, but horrible for any small river running. The pontoons would stuck often and turn raft suddenly left or right. Sidewinds on lakes did suck.
Second try was narrow cataraft (photo). 4,5meters with 1 foot diameter tubes. I have enjoyed riding down rivers with this but there are downsides. Pontoons close together form quite a wave between them cancelling any speed advantage of long frame and definitely getting you wet.
I would be cautious with rivers and 2 layer fabric solutions. If you get water between layers the raft will be heavy and difficult to control. Water probably must be removed on shore.
One idea for bottom protection is to fix a 3/4" plastic tube running along the keel line under the raft. It would take lots of rubbing and give some directional stability too.
Small rear fin is great to have
Inflatable will hit rocks 'softer' and be less prone to puncture, but must have zero leaks in order to work well. Skin on frame is maybe tolerable with minor leaks. In Alpacka style boat I'd expect most damage to be on middle bottom which is good.
For bonding together different sides of heat sealable nylon: couldn't you use a narrow strip of same fabric, in a way you would tape the edges together.
I think if you want packraft buy Alpacka, but that ain't the point of MYOG projects…Oct 29, 2009 at 12:53 pm #1540926
@vickrhinesLocale: Central Texas
That catamaran looks professional! Please explain the construction including the connection between the two hulls.
The center wave can be reduced significanly if you toe-in the bows… IOW form a shallow, open 'V' with the front closer than the rear.Nov 3, 2009 at 6:08 pm #1542372
Alpo KuusistoBPL Member
Photo would be handy here:)
Pontoons are just simple shaped tubes, one foot diameter at the center. Rear end is closed with a knot! Service and all modifications are easier this way. Long tubing for inflation goes in from the front end. Hose clamps here. Pump is always attached and rests between legs. This way tiny leaks can be tolerated.
Rigid part of frame is rectangle of 3 foot alu tubes 3/4 inch diameter. One crossbar is behind seat and one between seat and heels. Seat and footrest hang from the corners. As do straps over knees for bumpy water. (Right knee strap from right rear corner – between knees – to right front corner)
Attachment of frame to pontoons is done with glued in strips (of same PVC fabric) that run around pontoons.
Thanks for the toe-in advice. Probably will wait for spring anyway. (First skate tours on ice in few days)Mar 14, 2010 at 1:44 pm #1586349
We have spent some time playing with different designs of packrafts that are both durable and affordable, and believe we have a great solution. Our raft is 2 lbs 3oz has a 310 lbs weight capacity, and Radio Frequency welded for supperior strength. Please visit our website for additional specs and details.
AlexMar 14, 2010 at 2:05 pm #1586354
Rog TallblokeBPL Member
@tallblokeLocale: DON'T LOOK DOWN!!
Alpo: thanks for the comments and ideas.
Bender: thanks for replying to my email. I found that our two BA clearview pads fit and don't slip, but I may be back to you on your offer later. We have to save hard for a trip to Norway right now.
General comment to everyone: Water is fun but dangerous. Factor in some personal inflation device in case you have to abandon the raft. I have worked with a lot of different rivercraft from 200 ton barges to inflatable canoes. A feature of discussions between boaters are anecdotes about how people lost their lives.
ETA: http://www.coracle-fishing.net/ has some great stuff on traditional light boat building.
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