Hi @michael-s-morse,
I and a few others have experimented with fabric with TPU on both sides, but everyone has concluded that it is unsuitable because it is very difficult to heat seal – you can’t apply heat directly to it with a sealing iron because the iron melts the TPU, creating a sticky mess. You have to sandwich it between two layers of another fabric, which adds a significant amount of time and complexity to your build.
So far I haven’t seen evidence of the TPU-out design being less durable than TPU-in, but time will tell. If anyone wants to build TPU-in packrafts, they could use my original V1 plans (I still have a few sets available – send me a message if interested), or modify the V2 plans as follows:
1. Add ~4 cm length to the “tail” ends of the five tube patterns (each piece is roughly fish-shaped).
2. Cut the floor pattern in half, lengthwise.
3. Tape the five tube patterns to the half-floor pattern in their respective positions (numbered 1-5, between the circled dots on the floor).
4. Follow the instructions/videos for the original plans, currently posted at the bottom of the How-To menu.
Cheers!
