by matt walker » Sun Nov 02, 2014 2:15 am
Hi Jefe, welcome.
I personally don't think it's a good idea to cast the manifold. Uses a lot of material in a space where it's not needed. I think there are better ways to construct that part, and you certainly don't need refractory there, just plain mud will be fine.
My recipe in the video at the beginning of this thread uses the furnace cement to add sodium silicate, and increase the alumina content of the mix. It's an easy way to get those elements into a mix. You can add furnace cement to found clay and it will do the same. That said, David seems to be having a good time playing with mixes and it's been a very cool process to follow. I'm happy with my mix for simple castings, but there are a million ways to do it. If you really want to just get right to a good mix and don't want to play with the different possibilities, bagged castable refractory is an easy way to get there.