Thomas Kramm from Hackerspace FFM created some nice Silicone sleaves for the Merlin hotend. Since he uses different heating elements than I, he uses shorter ones that I currently don’t have, I created an own version of this cover.
It protects against blisters 😉 and will reduce the amount of heat lost during print. With the cover the already printed parts will not be exposed to the heat as much as without and you can be a lot less discriminate with material cooling.
You can find the STL for the mold attached
I used silicone meant for tin molds, it holds up till 450°C and i think it will last quite a while at the <300°C it is used in this case.