The one i had was made of pine,it did have an aluminium tube inside though.
Do you know of Heigham sawmills in Norrige?They have an good offcuts box..
I'll have to look them up!

I recently used cushions(sawmill) and they tried to rip me off, my brother said they did the same to him.
a
pine fire piston?
I would have thought pine is too soft, i have a fair bit of i think it's pine from some work I did, It's tanalised and i'm not sure what effect it would have to the eventual piston.
I tried to make one using scrapped tight fitting walking poles, Globetrotter gave me, it was going well i put tinder in and it was getting warm.
problem was i used wood to bung up the ends of the poles I hammered it in to make sure it wasn't moveing anywhere!
it had a good seal but not air tight, after chopping up a rubber glove and a foot or so of leccy tape, and plumbers tape, it worked....almost, hot tinder!
I thought more force is needed, so iput it on the floor, pushed with everything I had.....
bang!:yikes:
What the...****... was that!
basically I'd just made a POP gun!
when I realised what had happened (and the wooden bung had stopped bouncing around) it was funny, then I looked at the parts....the bit of wood had shot through a very tight hole, through the rubber glove and through the Leccy tape in one go!
was that a pop gun or an Air-gun I'd made?:theyareon