"Now you’re ready for sealant. You can use an aggressive sealant/adhesive here (like 3M 5200)
as you should not need to remove the thru-hull again. Do not use this aggressive sealant on the
threads going into the valve however. Use Teflon tape or other removable sealant on the threads to
valve connection. Follow all instructions from the sealant manufacturer for proper surface prep and
use. Read carefully the cure times required."