The Shop > Metal Stuff

Green Twin Oscillator Cast/Build

<< < (11/13) > >>

MetalCaster:
Hi David-

I try and resized them to 100k or less.
More than that and they can get a bit grainly.

Thanks for the feedback.

ironman:
Mine would sometimes break. Lets hope that yours are successful.

MetalCaster:
There is a bit of an art to making sodium silicate cores.

I have been experimenting with different percentages of sodium silicate, between 3 and 4 percent by weight of sand.

I have a core I made last week, and it is as hard as granite, and then another one that fractures easily.

I need to figure out how to get a consistent hardness to the core.

Too much sodium silicate and you cannot force the CO2 through it.
Too little sodium silicate and the core is too fragile.

ironman:
Have you tried using a microwave oven? Gassing them can be hit or miss if they are not gassed properly.

MetalCaster:
Nope, I have not tried that.

I can't pull the core from the pattern without hitting it with the CO2.

Navigation

[0] Message Index

[#] Next page

[*] Previous page