N00b here

[belgiumalaska]

Hey guys, I've been following many discussions about building a gas forge at home. I rigidized my kaowool lining with fumed silica with food coloring added in order to ensure it's fully covered. My next question is how long do I wait for it to settle/dry before I apply a satanite coating?

[Irondragon Forge ClayWorks]

We waited over night with a 60 wt incandescent light bulb burning in it. We also applied a coating of Satanite but found out it does not work very well and is a heat sink making it hard to get the forge up to temperature wasting a lot of propane. We then coated the Satanite with a coat of bubble alumina and it gets to temp fast and uses a lot less propane.

Since then a better refractory has come to our attention   Kast-O-Lite 30, which we will use instead of Satanite for our next build or if we have to reline our current one. Also a coating of Plistix 900F will help with the temp of the forge.

I can't control the wind, all I can do is adjust my sails. ~ Semper Paratus

[Mikey98118]

 

well, actually you can use that same burner in your forge try dry out, and then heat the forge up enough to melt the fumed silica unto the surface of the ceramic fiber (because fumed silica consists of very small molecule chains, which will melt just this one time at much lower temperatures than the ceramic fiber). Thereafter, the glass coating left on the fibers cause them to lock together everywhere they cross each other; this causes the fluffy insulation to take a rigid set, which will provide stability, to support the Kastolite 30 flame face.

[Frosty]

Welcome aboard Belgiumalaska, glad to have you, If you put your general location in the header you'll have a better chance of meeting up with members living within visiting distance like oh say . . . ME!

At one time we let rigidizer dry for a day or so before heat curing it but too many guys were just firing the burner right after coating and having good results. A number of us gave it thought, even discussed it and what the heck, there is zero chemical difference between dry and wet colloidal silica, just the presence of water. Drying with the burner can't cause problems.

Save the Satanite for something that doesn't need to be particularly fuel efficient, say mortaring bricks together to make a fire pit in the back yard. It is a mortar, not a flame face refractory. If you pick a proven burner design and follow the directions, satanite won't last terribly long. Kastolite-30 is a 3,000f, water setting, high alumina, insulating refractory. A MUCH better product for our purposes.

A final coat of Plistex 900 kiln wash does a couple good things for you. It is a last defense against the aggressive high temperature chemistry of a propane flame. It fires ceramic hard to help resist mechanical abrasion, has low thermal conductivity so traps the energy of the flame to radiate back into the forge to work for you. And last but not least it protects the refractory behind it from heat so it lasts longer.

And one last question, where in Alaska do you live. I'm on the Big Lake side of Wasilla about 2 miles from the Parks highway.

Frosty The Lucky.