I have a new forge made from a large freon bottle lined with ceramic wool and coated with rutland refractory cement. It had some cracked cement inside so, I proceeded to add some more refractory. I did let it dry but, due to humidity in the south of Mission, Texas, I didn't let it dry enough time. Used a propane torch to slowly heat up and it started bubbling (cement coating) so, I stopped. It sure looks ugly inside ? is, do I scrape off the new coating or just use it as is?. I have read from others that satanite can be a better substitute than what I used. I'm new at this at adding coating and all. Also, I can use ITC-100 to coat over satanite or refractory cement. Can anybody help me into what to use to re coat my forge, and where to get it for a good price?. Rey:confused:

I have had this happen before too. Even after letting it sit for a few weeks it would still bubble up. This usually happens when I used stove cement that I watered down so I could apply it.

Satanite doesn't do this.

I found that it will bubble up and look really ugly, but after running the forge for a while the bubbles will go back down. In fact, after everything was up to temperature, I could use a piece of steel and push the bubbles down flat. They usually don't come back after that.

Good luck.

Many thanks for the info. Rey

Thanks for the info, Wapiti--I've used the furnace cement in several projects and have had the same problem with the bubbling. I added water to the mix to get it from a thick, stiff clay into something more workable and also let it dry for weeks. I'll try what you suggest by heating and "re-forming" the bubbles.

-Chris

Edited October 21, 200916 yr by chrisfrick
grammatical errors

You can buy a few pounds of satanite powder for the same price as a few tubs of furnace cement. You also might consider ITC-100. Both are easier to mix and apply. They also last longer in the forge. Furnace cement will get brittle if you forge often and will start to fall apart.

Having said that, I know a few full time blacksmiths that don't even bother with coating their ceramic wool anymore. Their forge bodies are roughly 12-14" in diameter, lined with about 1.5-2" of wool. However, they do not forge weld in them. They could probably still weld in them if they at least coated the bricks on the bottom with ITC, or even furnace cement. The flux eats up the wool really fast.