FINALLY did my first Aristotle furnace

[Rogerrr]

I finally did my first Aristotle furnace run and it was a complete success even though it seemed to take much longer than usual. From loading the first piece of rebar to the end was about 90 minutes.

 

To make a long story short I had kind of given up on trying any smelting or melting of ferrous metals since I don’t really have a good place to do it. But recently I got a cheap stick welder which got me thinking about iron and steel again ( I usually melt & cast aluminum) which then made me realize the Aristotle furnace is perfect for my situation.

 

Since something like an Aristotle or the 7-brick hearth is so similar to what I use as a crucible furnace (except for where the tuyere goes ) I’m considering making a cylindrical bottomless furnace that I can rest on a bed of sand & use rightside up or upside down depending on whether I want the tuyere near the top or bottom … making it an Archimedes furnace 

 

 

[Alan Longmire]

That rebar is pretty big for an Aristotle, that's probably why it took so long.  Have you tried to consolidate the bloom yet?  

[Rogerrr]

Thanks….I was assuming my blower (320 watt 26cfm 1.6 psi air mattress inflator ) was the weak link. Since the instructions said not to run the blower continuously for more than 10-15 minutes I put it on a dimmer at about 70-80%….but the last 20 minutes or so it was at full blast and the blower didn’t seem to burn out or anything….

 

Only one load was rebar…the others were thinner steel rod wired together 

 

1st load was 140g

2nd 151g

3rd 183g

4th 176g

 

So next time I’ll try blower w/o dimmer and smaller amounts of metal 

 

Haven’t tried to consolidate the bloom yet. I’m going to wait until I have several since I like the way some blooms look and want to turn the coolest ones into sculpture 

 

 

Edited May 30, 2022 by Rogerrr

[Rogerrr]

Second attempt was slightly better. I used smaller rods as Alan suggested and tweaked my blower setup to get a little more air. Total time melting was now 1 hour instead of 1 1/2 

 

The tuyere seems to have clogged or something near end.

 

 

[Emiliano Carrillo]

So your first run was 650grams total weight going in? I generally charge about twice that much in my furnace, and it's about 25 minutes from start to finished high carbon puck. Your blower may be under powered for what you're trying to do. I would try using a shop vac with a ball valve hooked up, more pressure and air. 

[Rogerrr]

Yes I think that’s the problem…. I read that other people were using 100 grams of charcoal every minute or two and I was nowhere near that 

 

Thanks

[Rogerrr]

Got a small 50 cfm shopvac and did another run

 

Much improvement even though we discovered air leaks in the clay plug and where the air pipe attached to the furnace 

 

Total time still about an hour and I didn’t melt the entire intended load of metal…..but that’s because it took us so long to notice the air leaks

 

Also seems like my charcoal should be a bit smaller so it’ll settle at a constant rate….

 

When I removed the metal there was plenty of molten slag in the furnace—- didn’t notice any on the first two attempts 

[Rogerrr]

Did another run today with the new small shopvac and all leaks sealed as well as possible….MUCH better….furnace was much hotter and just devoured the metal I fed it — 3 stainless rods that were sitting around from a couple flatbed scanners I dismantled 

[Rogerrr]

Also for this last run I increased the height by about 2-2&1/2 inches since it seems like the interior height was a bit too short 

 

In another thread people were discussing smelting at this scale and Skip mentioned pelletizing the ore & using 1/4” charcoal….I was thinking it might be fun to try running the ore through…..then crushing up whatever accumulates at the bottom and collecting everything that’s magnetic and running it through a second time 

 

Or maybe try a cupola experiment….I’ve heard a lot about very small cupolas but never found any details 

 

In any case the furnace is getting weak and crumbly….so I want to make the last run or two some kind of experiment. If it’s going to die, it’s going to die for science

 

It’s a gorgeous day here…. Time to run off to the Chesapeake Bay and collect some bug iron

 

 

 

 

[Alan Longmire]

Let us know how the stainless pucks behave.