Bottle top valve installed in a seat. Some bottle tops (like this one from a Badoit sparkling water bottle) have a slightly lower profile. The valve is absolutely airtight without the screw top on, but deflates easily when the flap is pushed in with a finger tip. Works better than I thought. No going back now – I prefer this to the Boston valves I bought.
Also a good light weight valve for the seat or inflatable floor, with the added benefit of the inflation bag adapter (mentioned earlier) fitting all valves.
This reply was modified 7 years, 3 months ago by Jamie.
I’ve just had a go making a washer from a plastic container lid. If you cut the hole to the right diameter it will thread tightly onto the Boston valve. It provides a good airtight seal and won’t pull off.
In fact a good quality bin liner bag, some plastic from a food container for the washer (something sturdy, but with a bit of give) and duck tape should do the trick, if you want to improvise.
The rubber I had was ok, but a little too floppy to create a firm grip. I had some 0.9mm thick TPU sample film called Tuftane which was perfect. Can also just use duck tape to secure the washer to the inflation bag. I have a cheap compass cutter from eBay which cuts perfect circles – definitely recommend investing in one of those.
The Neo Air has a short internal tube made of a thin plastic film, which is bonded to the rim of the outer tube opening that is part of the shell. The internal tube acts as a valve (similar to the type of valve on some disposable inflatable pillows), whereby the internal pressure causes the valve to close up, thus providing an airtight seal. Maybe this is the way to go – seal a thin TPU tube (2 rectangular strips bonded along the two longer sides) around the rim of the roll-top opening and let this tube hang inside the packraft acting as a valve. Obviously this works for the Thermorest, and I have had success with this type of valve on an air bladder. Definitely worth giving a go. I’ll report back once I’ve had a go.
<p style=”text-align: left;”>Thanks – I take your point about the difficulty in getting an airtight seal. I have made air bladders out of TPU film (rather than TPU coated nylon). The material is stretchy and kind of clings to itself, so it wasn’t difficult to create an airtight seal. Maybe I’ll try and bond a tube of this stuff to the TPU coating and see if it works. For a 50cm opening, the zip is probably the way to go, but this could be useful for a narrower opening just to provide access for leaks and repairs.</p>