A local wood yard 'kindly' offered them ten 'hardwood' logs to use, the lady organising the project collected them in her horse trailer and brought them round, upon opening up the trailer I was confronted with one partly rotten Oak log and nine half rotten softwood fir trunks, years old and soaked in muddy water...great!( I have dealt with this woodyard in the past and wasn't in the least surprised at their 'kindness'..........)
I felt bad telling the lady that this timber was no good, completely unsuitable for making the seats from especially as they can't be treated with chemical preservatives ( you can imagine how quickly even a fresh piece of untreated fir is going to start decaying and how rough the end grain tops would get as the soft part of the grain structure goes, leaving that ridged texture....).
Thankfully after our disappointing start she managed to get some nice Oak logs elsewhere which were perfect for the job! I turned them on the lathe and made sure all the surfaces and edges are sanded smooth with absolutely no splinters to keep all those little hands safe!
My kids were very keen to test them out before we delivered them!