I learned this overseas. It doesn't remove the air but it comes close and it seals. It takes a bit of skill to get the seal correct.
Put your stuff in a waterproof bag. We often use zip locks, but a sleeve of plastic sealed in this way at one end. The open end will be sealed in the following method:- Light a candle. The need for this will be clear later.
- Close the bag most of the way OR fold the open end over itself three times.
- Immerse the bag (bucket, bathtub, whatever) into a sink full of water allowing air to escape.
- Finish closing the bag.
- Hold the newly closed end taut.
- Then, hold the closed end in the invisible flame of the candle which is an inch or two above the visible flame. This part is tricky because too close and you'll melt the plastic all over your fingers and that hurts! Too far away and the plastic won't melt. There is also a risk of dangling the entire bag in the flame and that's no good at all.
- As the folded plastic melts, pinch the plastic together quickly so that it pushes the sides together, BUT you don't burn your fingers.
This is a developed skill. It is easier to demonstrate than to write about. We used it in '95 when I first arrived in the jungle. I haven't used it in about 20 years.
I’ll say that is definitely a developed skill, Jem!
Old school, but does the trick, right?
And...requires no electrickity.
Thanks for sharing that tricky trick.