We Think We Understand the Furnace (Session 8)

I think we finally understand how the furnace works. I mean, we've been successful on different occasions and one way or another melted bronze, but sometimes it would take 2 hours, other times 2 hours with the bellows, other times 3 hours and lots of charcoal and lots of bellows action, and this left us with the feeling that we didn't really understand this furnace yet.

I think that now we do. 

The key is in the crucible placement. At 1:30 pm we started the fire and while the charcoal got going, we prepared the crucible (975g of bronze, from session 7 + other bits). We then placed it low down in the furnace, on a bed of charcoal but not a deep one. 

And then we covered it completely with charcoal. 

And then we did nothing. Well, we weeded the garden a bit and pruned the tomato plants a little, but basically we sat and watched the furnace and did nothing. 

After about 30 minutes, the charcoal collapsed a bit so we topped it off again. We did that again 25 minutes later, and then at 2:50 one more time, and by then the charcoal had a lovely blue and yellow hue to it - a clue that something new was happening within. 

 

At 3:20, we tested the metal and it was soft but not entirely. So we added a bit more charcoal for a final push. At 3:45, it was all totally red hot, and the metal was melted. 

We had read that adding perlite could help to gather the dross, so we did that, but we're not sure it really helped at all. We think unexpanded perlite might work better? In any case, we scooped out whatever dross we could and got set to pour. 

(the molds weren't on the table for the pour, no.)

Even if a little dirty, the metal flowed beautifully. The molds, though, were not very good. They were the cracked ones from session 7, and the yoni lingam mold actually still had wax within it! So flames came out of it for a while. 

(We think we really screwed up that burnout session, cracking most molds from too much direct heat and even then not managing to burn out all the wax in this mold. Note: go much slower next time!)

This is what came out: 

It was 4:20pm. There was still a lot of bronze in the crucible so we decided to try to go for a second melt. But we couldn't get the crucible down as low as the first time since the furnace had lots of charcoal in it. So we figured this would be the perfect test: if we put the crucible in and covered it with charcoal and it melted fine, okay. But if it didn't, we would know that crucible placement low down is the key. 

We sat and did nothing, just watched (more on the importance of "doing nothing" in a future post). At 5pm, we topped up the furnace one more time with more charcoal. 

We did some more nothing. And then at 5:30, we checked.

Nope. The crucible was not totally red and the bronze was still solid. Getting slightly soft but still solid. So, conclusion: the crucible low down in the furnace is key!

How often do you learn things? I mean, really learn something, really figure something out? As time goes on, we realize that this is also one of the joys of the fire craft as developed by Silo - encountering problems, getting stuck, being unsure, and at some point, figuring it out. It's a direct consequence of having permanence, one of the three main positions or attitudes that the Crafts are meant to develop. Seeing this kind of learning in action is a thrill, and so very satisfying.

(It's also one of the joys of the spiritual path as developed by Silo. Can you turn your difficulties into stimulating challenges? Can you take your getting stuck, your being unsure, your very problems and make them signs indicating where to build more strength, wisdom, and kindness? Can you turn the raw material of daily life into fuel for unity within? The Principles that Silo expressed in his book, The Inner Look are probably the best way into this approach.)

So, now that we know this about our beautiful furnace, we'll have to try to see if we can make bronze without bellows (we tried before and were not able, but was the crucible down low enough?). And really we need to improve our molds and castings. It's time we produced some pieces that we're happy with, that demonstrate some minimal mastery. 

Because The Iron Age awaits!