the lowest setting on ours says 80 which is what i used,not sure what that is in gas,just keep an eye on it,if it starts scorching turn it down.
there is another trick of boiling in salt water,the salt breaks down the cell structure within the wood and draws moisture though your limited to the size of wood you can fit in a pot.
i tried this on a piece of beech and the water ended up red with the sap,really did dry it out...atb kev