Now thats the molding silicone i need ^^
e3d hotend cover
Did you put any kind of release on the plastic?
@Daniel_Kruger Well no ill try without first 
What kind of silicone did you select?
what did you end up using?
@Tom_Keidar
Its moldingsilicone for TinMolds. 350°C+ and reaaaally runny Got it from ebay (germany)
@Tom_Keidar Any silicone made for making casts for tin or other low melting metal is fine. They are made for up to 450°C and are very viscous. I’m german, so I don’t know the exact brand you should choose in the usa, but google with the information given should work, too
@Daniel_Kruger You don’t need one, if printed in ABS or PETG. I don’t know about PLA…
And scrolling through this thread: http://forums.reprap.org/read.php?252,584458 and just downloading any provided STL should show you some of the best casting molds the german sub-forum came up with 
Especially the one of user “dolphhund”.
@Tom_Keidar its from ebay BUT here is the website of them: http://www.trollfactory.de
If provided this link by @VolksTrieb , than I recommend the red one. I did also some postings about exactly this stuff: http://well-engineered.net/index.php/en/component/tags/tag/9-silikon
@VolksTrieb @Rene_Jurack thanks guys - i’m actually from israel and not the u.s, we have plenty of local sources for these types of stuff but it’s pretty hard to get for a hobbyist - the prices would be extremely high.
so my suppliers are basically ebay or aliexpress… so thanks for the links guys
to get 2020 extrusions (getting them from abroad was too pricey in terms of shipment) i had to ask a cousin who works in construction to get one of their aluminum contractors to help, plus side was they had a pretty decent amount of 45mm length of 30x30mm aluminum square profiles - i got about 20 of them (for my 2nd machine - corexy).
i’ve made some TPE vibration dampeners for my printer, which work extremely well (inspired by @Rene_Jurack 's molded feet), and this mod seems like it could offer better temperature stability while using stronger cooling - which means i can print even faster (doing ~120-150mm/s on my i3 currently).
I’d love to see pictures of it installed. I’m thinking about adding one to my hotend.
@Daniel_Kruger
No need for a release agent at this size. Despite the rough surface.
How is it working out? Improvement?
Well the model is not that good.need to redesign it a bit. The burls on the silikone are in the way somehow