urgent help – fixing mistake v3

[sldrose]

i mistakenly sealed the  L3 inner tube from either side, forgetting the tip to seal outwards from the middle for the second half.

I now have a huge fold in the floor.

what can i do? can i reheat, separate then reseal?

can i reseal with the iron, or will i need glue?

also ive overheated the floor even though i had baking paper underneath it. Is it still waterproof or will i need to put another layer of tpu on top of it

any help welcomed

thanks

Topic

[sldrose]

inner reinforcement

[sldrose]

Thanks Matt,

I managed to reheat and separate the fabric. The TPU did separate in some places. I assumed that this means that it wont reseal??

Can you reseal TPU once if the TPU has lifted?

I wasnt sure if it would re-hold, so I reinforced with a second strip.

The inner reinforcement strip is attached to the base and to the non-tpu side of the tube.
Will the TPU side bond with the non-TPU side of the tube?

I’ve run into this situation a few times and i’m unsure if i should use TPU to non TPU side or seam-seal glue. Do you have a preference for strength?

thanks

Sean

p.s. im really enjoying this project. I have an appreciation for what you would have gone through to figure this out without instruction.

also, i tried the bowl and the form, but neither worked until i had the double sided masking tape on. It made all the difference.

cheers!

 

 

 

 

 

 

[Matt (Admin)]

Hi Sean, I’ve found that the TPU to non-TPU welds aren’t very strong, and with all the rolling and unrolling a packraft goes through, it probably won’t hold forever, so I’d put some Seam Grip (or similar) around the edges so if it does separate there at least it won’t leak. The seam sealing glue isn’t great as a structural adhesive either, though. For that you’ll need a different glue. People have told me that HH-66 works well, and there’s another one whose name escapes me at the moment… I think it starts with a “B”. Also, 3M makes some permanent adhesive tapes that work on the fabric. I don’t have personal experience with any of those things though.

It’s hard to say how the part that was unsealed and then resealed will perform… it sounds like only part of it had the TPU separate from the woven fabric when you unsealed it, so it should be okay strength-wise, but again, I’d probably give that area a coat of Seam Grip – not so much for strength, but to prevent any leaks from developing.

When in doubt, I like to bend and fold the welds sharply several times to make sure nothing separates. There’s going to be lots of bending and folding every time you roll up your packraft after it’s done, so it needs to be able to handle those stresses without any problems developing, and it’s much easier to fix things while you’re building than after it’s done.

I can’t even count the number of hours I’ve spent figuring this stuff out… I think it was around 200 hours before I decided to make a website in 2015. Since then I’ve had lots of help and tips from great people around the world though, and that’s helped a lot! The masking tape trick is a perfect example – a guy named Mike in Seattle was the first to suggest it, and then Bruce in Fairbanks was the one who really showed me the light by actually sending me a wooden form with tape on it so I couldn’t possibly ignore it. There are some really great people in this little community!

[Matt (Admin)]

Oh, and it should still be airtight even where it’s overheated. Cheers!

[Matt (Admin)]

Don’t worry – this is not a huge problem! If you can’t un-seal one side by reheating it and peeling it up, and then redo it (which you probably can’t), then I would cut a slit in the floor fabric perpendicular to the edge, long enough so that the fold disappears. Then simply cover the slit with patches – one on the bottom of the packraft’s floor and the other on the top. Make the patches out of 250 GSM (210D) fabric. The patch on the bottom should cover the slit and also extend onto the tube fabric so that it’ll make an airtight seal. It won’t be pretty, but it’ll be on the bottom of the packraft, so no one will see it. Cheers!

[Author]

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