Make an Inflatable Packraft Seat – Free Plans Version

Here, I explain how to save yourself $100 by making a “deluxe” inflatable seat for your packraft in one evening.

Start by tracing, stenciling, or transcribing the shapes from the free plans available here onto your fabric – two of the large coffin shape, and one each of rectangles A through G. Also mark the end locations of lines A through G on the TPU side of the larger pieces. Use a non-permanent marker if you don’t want pen marks on your finished seat. Label the rectangles A through G, and then cut out all the shapes.

Lay out one of the two large pieces, TPU side up. Align one edge of rectangle A between the dots, and then use your iron to seal approximately 1.5 cm of its edge in place. Press firmly to make a strong bond. Don’t bother trying to seal it all the way to the edge, because this joint will be on the inside of your seat, so it won’t be visible, and you could compromise the airtightness of the fabric if you accidentally melt the TPU surface on the larger piece. (If you do happen to melt an area you didn’t intend to seal, simply patch it with a small scrap of your fabric.)

Seal rectangles B through G in the same way as you bonded rectangle A, above, keeping them all oriented in the same direction.

When all of the rectangles are bonded to the first large coffin-shaped piece, lay the other large piece on your work surface, TPU side up, and bond the rectangles to it in the same way. (Before starting, think through your next steps to make sure you start at the end that will allow you to easily access each subsequent rectangle.)

When all of the rectangles are connected to both the top and bottom of your seat, mark the location where you want to install your valve. I decided to center mine between rectangles F and G (between my knees when I’m paddling – accessible, but out of the way). If you use a Small Valve, Aquaseal works well for gluing it in place – just cut a hole, cover the flange with Aquaseal, set it in place, and leave it overnight to cure. You may also choose to use a top-up valve or a Boston valve, in which case I recommend using the updated installation method posted here – it will be much easier if you do it before you seal the baffles to the top and bottom of the seat.

Once the glue has cured, use your iron to bond the edge of the seat’s top directly to its bottom, all the way around the perimeter in a band approximately 1.5 cm wide. Press firmly to form a strong bond, and do your best to avoid/work out any folds in the fabric that could let air escape.

When you’ve finished joining the top to the bottom, wait for the seams to cool, inflate the seat with your mouth, and sit on it. If it holds air, congratulations! If not, find the leak in the perimeter and re-seal it, applying lots of pressure.

If you like, you can trim a bit of fabric off the edges to make a clean-looking edge, and with that, you’re done!

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One thought on “Make an Inflatable Packraft Seat – Free Plans Version

  1. Hi James,

    There seems to be a “Goldilocks” temperature that is not so hot it melts the coating off and is not so cold it can be peeled apart. I don’t know what this temperature is because I don’t have any way to measure it, and I have to find it by trial and error. An adjustable-temperature soldering iron helps. The other key to getting a good strong bond is pressure – I press pretty hard when I’m sealing the fabric. Then I let it cool fully before testing it (if you put too much stress on it while it’s still hot, it will come apart). Finally, if you still can’t sit on your seat without it popping, you could try adding reinforcing strips along the inside of the perimeter joint (see a drawing of how this works on the “TPU In or Out?” page).

    Lately I’ve been using a glue called AquaSeal, but on my valves I have used a generic plastic cement and it has held so far – I haven’t figured out the absolute best glue yet because it hasn’t been an issue for me (yet!).

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