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Time: 45 minutes per seat.

This video demonstrates how to assemble one of the seats.

The seats for the 2-Person DIY Packraft are simple inflatable pillows designed to raise the paddler to a canoe-style paddling position. They’re unstable when used outside of the packraft, but constrained by the packraft’s tubes they do not roll around. You can adjust the height and comfort of the seat by adjusting the amount of air inside.

Assembling the seats is relatively uncomplicated and is a good place to start your 2-Person DIY Packraft project after practicing the heat sealing technique and dialing in your iron’s temperature.

To assemble the seat, watch the video above and/or follow the steps below.

Note: The tabs on the edges of your seat pieces are slightly narrower than the ones shown in the video above. I recommend drawing a line and/or using a straightedge to guide your iron in a straight line between the corners in order to prevent leaks from forming when the seat is inflated – see image below:

This picture demonstrates why it is important to seal the edges of the seat together in straight lines; if the edge of a weld is not straight, all of the inflation force will be focused on small areas instead of being distributed along the entire length of the weld, and the airtight TPU layer may peel and break, as shown here.
Seat pattern, not to scale. The seat is constructed from a single piece of fabric that is folded into a simple box. Start by separating it from the scrap fabric with your scissors.
These diagrams make it look a bit complicated, but it’s really very simple. The pattern has a trapezoidal tab extending from each edge that will be heat sealed to a corresponding tab on another edge. In this image, the matched tabs are color coded; each pair of tabs that are the same color will be sealed together. Label the tabs if you find this confusing.
When the 2D shape is folded into a 3D shape, the matching colored tabs all fit together. The yellow and magenta tabs are hidden on the other side of the model – you can see them in the image below. (Before it’s fully closed up, the box is pulled inside out so the tabs are on the inside.)
Rear view.

Clear as mud? Let’s get started.

Start by laying out the cross-shaped fabric with the shiny TPU side up.
Fold one arm of the cross over so the tabs line up, one on top of the other.
Use your heat sealing iron to first tack the tabs in place, and then seal them fully together.


Note: As mentioned above, the tabs in your kit are slightly narrower than the tabs in the video and pictures shown here. Rather than aligning the edge of the iron with the edge of the fabric, draw a straight line and/or use a straightedge to ensure your welds are straight.

When that’s done, rotate the top part of the fabric clockwise so that the next two trapezoidal tabs line up, and seal them together too.
Sealing the second pair of tabs together.
Before moving on, make sure there is no gap left unsealed at the corner (under my finger in this picture). You can iron it to about 5 mm (1/4″) from the edge here to ensure it won’t leak.
Seal two more adjacent tabs together, and so on, until just one edge is left unsealed.
If you haven’t already done so, remove the 4 cm diameter circle of fabric that is scored into one end of the seat.
To make a stable base to press against when you iron the fabric to the Boston valve, use a piece of cardboard with a hole cut in it, and place it on top of a roll of tape or toilet paper.
Cover the cardboard in parchment paper so the fabric won’t stick to it if your iron goes beyond the edge of the valve’s flange. Place the valve in the hole so the flange sits flat on the parchment paper.
Place this stack under the hole in the fabric. Make sure the valve is oriented so the threaded side is pointing down and the part with the three raised bumps is pointing up. Seal the fabric to the valve’s flange.
Now let’s work on the last edge. Seal it about a third of the way in from each end, and then check to make sure all of the corners are sealed shut before reaching in through the last unsealed gap to pull the seat right side out (TPU side out).
Since we can’t iron directly on the TPU side of the fabric, we have to seal that last gap with a separate patch of scrap fabric. (If you want to make the seams extra strong, you can seal patches across all of them in the same way.)
Seal the patch to one side of the gap first.
Flip the fabric over and fold the patch over onto the second side. Seal it in place.
Make sure there’s an airtight seal where the patch covers the seam. Avoid ironing too long in one place or the TPU might melt on the underside of the fabric below.
Assemble the Boston valve by slipping the large ring (under my thumb) over the threads and securing it with the retaining nut (held by my left index finger).

Inflate the seat with your inflation bag and test it for leaks. If you find a leak, seal a patch of fabric over it.

Tip: You will find this seat more comfortable to sit on if it is not fully inflated.

To avoid losing your seat, seal one of the included attachment points to it so you can tie it to your packraft.

Onward to the 2-Person DIY Packraft assembly instructions!

10 Comments

Marko · August 18, 2022 at 6:35 pm

A year after completing my two seater packraft I finally made it to the seats :). Well, I think the design is not good because of the 3 piece corner meeting where leaks occur. I personally think a 1 piece, pillow case style is better and easier to construct. It would be similar to making a inflation bag just folding corners to give depth or thickness to the resulting pillow. Another thing I would not do is leaving a gap and trying to seal after turning bag out. You than sealing blind and via several payers of material. Instead, seal all around without leaving a gap, then, cut a a line somewhere 15cm long, turn bag inside out and seal with a patch. I find it easier, and most importantly very well sealed.

Simon · August 27, 2021 at 5:18 pm

Hi Matt.
Thanks for such great products and advice.
Have finished a Telkwa and its great but must say this canoe seat is not working well for me. The edges on the video above seem much wider than those on my template (the video edges are as wide as the iron so approx 27mm but my edges are pre scored with a depth of only 10mm).
My first seat leaked like mad and needed re-enforcing everywhere + glue (drying now so fingers crossed).
For the second seat I was thinking of making the edges much deeper but fear this could turn it into a rubik cube challenge. Any suggestions? Do you have the plans/dimensions for your original?
Thanks.

    Matt (Admin) · August 27, 2021 at 6:29 pm

    Hi Simon, thanks for the question. I made the tabs on the production models a bit narrower to make the fabric layout work more efficiently, but I didn’t think to mention that above – my apologies. I’ll update the instructions. For strength purposes, a 10 mm weld is plenty, but I’m guessing what happened is that with the narrower tabs, you didn’t have a fabric edge as a reference to align the iron with, so the welds aren’t straight, which means that when your seat is inflated the force gets focused on small areas of the weld rather than the entire length, resulting in the TPU peeling in those areas… I should have anticipated that this would create problems for people, and I’m kind of surprised you’re the first person to bring it up. I’ll add a video to this page that explains how this happens and how to avoid it. For your second seat, it should work out fine if you want to make all the welds wider (iron width, deeper than the tabs) and use the fabric edge as a guide for your iron; alternatively, you can use the existing tabs and draw a straight line to follow and/or use a straightedge to guide your iron so each edge has a completely straight weld, except at the corners where you need to round the welds off a bit where the edges meet. I might not get to this tonight, so if you’re not sure what I’m talking about, please move on to work on something else until I’m able to update this page. If you’re not able to make the first seat airtight, please send me an email and we’ll sort it out.

      Simon · August 28, 2021 at 3:31 am

      Thanks Matt.
      First one seems OK now I’ve put re-enforcements on every edge and aquaseal on the corners. I’ll trust in the 10mm for the second seat but follow your great suggestion about guidance lines this time around.

Hedley · April 17, 2020 at 7:29 pm

Hi Matt,
I’ve finally got around to attacking my DIY packraft. Inflation bag went together well, and then I moved on to the two seat. the first one, after finishing assembly, I discovered multiple leaks in the seams (live and learn), so i took a lot more care with the second seat. Seams all seal a whole lot better, but sadly the two corners where three seams meet are both leaking, despite my best efforts. What would be the best way to seal these two leaks?

    Matt (Admin) · April 18, 2020 at 9:59 am

    I would seal a patch of fabric over the leaking area – that should do it, but if not, add some Seam Grip or Aquaseal.

Arthur Brault · December 16, 2019 at 2:55 pm

Hi Matt,
Great stuff and thanks for all the information ! Any rough idea of the m2 needed for 2 canoe seat ?
Best,
Arthur

    Matt (Admin) · December 16, 2019 at 4:41 pm

    These seats are included with the 2-person DIY Packrafts, but if you want to make some it’ll depend on how large you want them to be. These ones take about 2 linear meters of fabric for two seats.

      Arthurb · December 17, 2019 at 2:07 am

      Thanks Matt, Just wanted to check my quick calculation.

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