I was hesitating to provide data until I could reference my notes, which
unfortunately seem to be lost to time.
so from 20 year old memories.. taken with a grain of salt..
Im pretty sure my 4 inch motors used 1/8" aluminum case and 1/8" liners. Burn
times typically ran 4-6 seconds at 600-800 psi. I never experienced a
burn-though. Note however, I never tried to reuse the aluminum case. It was
disposable. Unfortunately I don't remember the grade of phenolic, but given my
frame of mind at the time Im sure it was cheap, probably surplus. I had cast
quite a few smaller core-burners directly into the case without a liner and
never had any issues either. I don't remember ever using both a casting tube
and a liner.
My memory is less clear about Urinisco's motors. I think his six inch motors
were built using 1/4" aluminum tube and 1/4" phenolic liners. Burn time was
probably 6-10 seconds. Ron's bates grain motors also did not use separate
casting tubes and liners.
Attached is a drawing how the bates grain stack was put into compression inside
the case.
--MCS
.