Foundry Project Page 13

I forgot to get a picture inside when it was done, so this one will have to do. The furnace is 99% finished at this point. I merely added a bit of sand to level off the bottom and then rammed it like mad, to make sure it was all solid.

A note on the cardboard insert. It worked well, but I needed to use a large and very sharp butcher knife to cut it off, level with the top. I then used a utility knife to slit it up the center. This will let you fold it in on itself so that you can easily remove the form. I can make 2 more furnaces with the remainder so I'm happy for such a small investment.

Here is the finished furnace with a small fire starting inside. For my first light, I was afraid to squirt the lighter fluid in directly. The sand was still wet and I did not want to weaken any bonds. I therefore, let the charcoal outside of the furnace and placed it in there, after it started to get gray spots on it.

I also took my lid out of the oven a lot earlier than Dave Gingery suggested in the book. I only got to bake it at 400 degrees for about 1 hour. I hope it will be ok doing this, but I figured the firing of the furnace would finish vitrifying the lid just as it would the body of the furnace.

I decided to put some screen over the top so that I could keep the ashes to a minimum. I will be surprised if the screen holds up. It will probably melt through, but I had scrap screen lying around so what the heck.

Just another shot of the furnace still burning without the air blower. My tuyere is rather large and in retrospect I should have kept it a bit smaller, but it is done now. If it is a problem I will fill it in with something to try to make a smaller hole.

Here I have added the blower now. It is running nicely and doing a good job. I re-read the Gingery book 3 times in the spot where he speaks of the furnace construction. I think I finally understand that he meant to leave the small metal pipe in the furnace, but I'm still not 100% sure. So I will try that when I make a new one.

I am wondering if my PVC pipe will withstand the heat? With such a wide tube, it may not keep the plastic cool enough? I will find out soon enough I suppose!