We use them at home and they are remarkable. A king size duvet, sheet and 2 pillows will reduce to the size and feel of a small, hard memory foam pillow
Bastardise an air pump or just get one that deflates as well as inflates. I daresay you could use a push pull pump too - it's fairly low tech!
ON a different and totally irrelevant note about adapting things for a different purpose I have a mechanic friend who took a fuel pump from an Aston Martin DB9 and jerry rigged it to a weight and a bit of wood to make a water pump for emptying a giant paddling pool! :D
Hiyas we have used 1's from Poundland, Home Bargains etc & most have been great . What i have found is the 1's that you roll, squash manually are absolutely fab. You then don't have to worry about deflating & using pumps etc either battery or electric. The Home Bargain large 1's 2 in a pack £2.99 or £3.99 ( sorry can't remember which ) will hold 2 single quilts 2 pillows & 2 single sheets no peoblem. We use then at home for the spare bedding & to take camping.
we use some lovely soft plastic vacuum bags from Tesco for bedding and clothes etc...they seem a lot more sturdy than the regular plastic ones such as the JML variety...the tesco ones can also be rolled to remove air...
we deflate them using our Dyson at home, but when in the tent we use an excellent manual hand pump called an air hammer (we bought ours at Wilkinsons) which can be switched to deflate...
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"tereba nessa, kemer wyth"
.~*MOONIE*~.
Snowdonia - Peak District - Brecon Beacons - Lake District
We have the argos large ones (think about a tenner for 2) and manage to get dbl duvet, 2 fitted sheets, 3 pillows and some fleeces in no probs. the other one we take our clothes and towels in. They are fab and save so much space and like others we use our battery pump (campingaz 4d) on deflate to pack them up.
Gonna buy some more actually (maybe b&m or poundlands) for spare bedding etc storage at home too.