I have collected some, with the approval of the site owners, nay, with the enthusiastic approval of the site owners.
There is a lot you can do with pallets. You can build compost enclosures. Here is one from my garden - 6 pallets and 12 cable ties and you have a really good compost bin.
You can cut up pallets for firewood. Breaking them apart is hard, a circular saw is the best way I have found. Only use untreated or unpainted pallets for firewood as burning the other sort will give off various toxic substances . Pallets range in size and construction but most have rectangular blocks in the corners , middle and centre positions to take the weight. These burn especially well, though on some they are made from compressed wood chips and unsuitable for burning.
the pallet plank wood is soft wood and burns very well but rather quickly. Sometimes it's worth taking 4 or 5 pieces and nailing them into a single log size piece. One nail is all you need, but it can slow down the rate of burn in a stove.
These and any other nails present can be carefully fished out of the ash at the end with a magnet
Compost bins
You can make composters out of all sorts of things. Old leaky water butts are good. I just cut the bottom section off , along the raised line.
Another Dalek here (see other blog entry on Daleks), incorporating the drum of an old washing machine as the torso. Makes a great incinerator for the rare times I need to burn diseased wood in the garden.
A collection of different composters, some bought and some made from old water butts on freecycle
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