did you receive my last pm? i found the sandblaster.
MULE
to insulate the locker use 5/8 fire rated sheetrock on the outside. you could also double wallit. find 1 locker smaller then the other and use the s/rock inbetween them. i don't know how hot you need to be. however a lower heat for a longer period of time will work also.
for small areas i use my heat gun to get better adhesion when touching up.