Perlite and Sodium Silicate Cake

After about a week it has sort of dried.  Some is still soft so I opted to bake it in the burnout oven at aluminum casting temperature 740C in this case

It came out rock hard or close to it.

Now I need to do some experiments.  Make up samples with variations.

These come to mind:

1:   I want to make channels to lay the coils in.  Preferably with a lip to keep the coils from dropping out.  This eliminates the need for retaining wires.    In this test I will try using a wood former embedded in the mix.  The idea is that the wood will turn to ash as the SS bakes.    Now the actual furnace will be made with new SS and not require baking to set.   I will have to provide some initial heat to burn out the wood.    Styrofoam might be melted out with a torch.  So that may be a better choice.

2. Add silica flour to the sodium silicate.   Not sure what this will do have some ideas but will not put them down here.  Just have to see.

3. Try curing the old SS in a bucket of C02 for a few days.   Try thinning out the SS with water.  This batch is very thick.