This should link you to the copper rtv gasket maker
https://www.mcmaster.com/#catalog/122/3463/=15r71j0
u want the permatex 81878, can also pick this up in most auto parts stores.
This should be the material used. I used the 1".
https://www.mcmaster.com/#catalog/122/851/=15r724i
This is the teflon tape used to wrap your mold. I used a 1/2" alum wing tube. Also wrap around the outside to hold shape while setting up.
https://www.mcmaster.com/#catalog/122/3488/=15r72bu
Pair of gloves and wax paper for the table is advisable as it is pretty sloppy while doing. I'd recommend two wraps if using the 1" material. A single wrap blew out on me, but they work great.