Casting Tutorial: Pouring A TC-5130F Coffee Cup Prop

In this tutorial video I cast a prop coffee cup from a mold made in a previous video (linked at the end). Just to make this interesting, I cast silicone into silicone. The original mold was made with TC-5110F fast setting silicone. I cast the coffee cup in TC-5130F (also fast) silicone. To keep the two from sticking, I applied petroleum jelly to the inside of the coffee cup mold and then sprayed it with Zip 301 Mold Release. If done properly, the petroleum jelly will not obscure the detail in the mold. I apply the petroleum jelly heavily, let it sit for about 10-15 minutes, and then wipe off the excess. I then spray the mold with Zip 301 mold release and allow the release dry/outgas. Once the mold is properly released, I am ready to pour my silicone.
Here's what I used:
Zip 301 Mold release: bjbmaterials.c...
TC-5130F Silicone: bjbmaterials.c...
Silicone Pigments: bjbmaterials.c...
My totally awesome apron: bjbmaterials.c...

[@Bren0780K]

I always like that whenever you say "The clock is ticking" or "Time is of the essence", you're always so relaxed as you casually tidy up before moving on with the actual mixing 😄

[@brickintheyard]

I live on the edge!

[@TheZahnputz]

really good summary! I had to cast hundreds of silicone hands in seamless silicone molds a while back. Your tip not to use a silicone oil for release agent is very important - i wish i didnt have to find out the hard way! Since this is the internet i'd like to add some infos for whoever might be interested :D
- Silicone oil release agents (like "Ease Release") may actually be advertised to release silicone from silicone and contain a very thick silicone oil dissolvet in alcohol (similar to mineral spirits) - this thick oil gets more liquid at higher temperatures, completely loosing its releasing properties - eg. if you heat up your molds (the working temperature should be mentioned in the data sheet though!). The same will happen to vaseline (which also makes it way easier to apply thinly) BUT it won't mix with the fresh silicone and will still release!
- different silicone durometers can be used to self release (or glue together!). A hard rubber forms more crosslinks which apparrently makes it stick better to a soft mold. A soft rubber "cures less" which makes it stick less to a harder mold. i found this to work across several brands but i obviously didn't test all the brands so please test yourself (and let me know if im wrong!)
- when you cut up silicone some of the polymer chains get exposed/opened which makes fresh rubber stick better
i hope this helps!

[@brickintheyard]

Thank you!

[@BigP.P.]

thank you for the product links!

[@brickintheyard]

No problem!!