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so i have finally convinced my local blacksmiths' guild to diverge out of their comfort zone and run a crucible melt this friday. those of you who may be local to the northern VA area are encouraged to stop by. it really looks like it should happen.

 

eventually my goal is to convince them to run a bloomery at the local spring fling, but safety concerns on the part of the ruling committee means that i need to operate on the baby step approach, and convince them that there are people locally who may be interested... anyway it is happening because i convinced them that guild members also may want to do aluminum and bronze casting. long story.

 

since i habe never done a steel melt before, only seen it at 'fire and brimstone' last year, i am going by what i have read here and elsewhere on the internet, so bare with me and let me know your thoughts on my plan.

 

first, i want to start small, and try a few different things to begin seeing what works for me, and hopefully do this again. second, i so not want to royally screw up. third, have some fun.

 

i have 3 different size crucibles. two are A2 sized and one is A4 sized. the first crucible will be filled half way with about 720 grams of cut up nails. i will add carbon, in the form of activated charcoal, and shoot for a carbon content of about 1% keeping it simple. the second crucible will also be filled with about 700 or so grams of steel, shooting for a carbon content of 1%. however, to this i will add cut up ni-chrome wire to shoot for a nickel content of about 2% and the chrome along with this to add some other carbides.

 

the third, larger crucible will be filled, again with old nails, and a carbon content of 1%, but i want to add some other carbide formers. my thought is to use a plain, uncoated HSS drill bit, and add this to the mix.

 

questions:

 

1. if i use new, unused, crucibles will i run into issues.

2. if i need to season them, what should i do given i do not hqve the ability at home to do anything.

3. i plan on covering with glass for flux, but should i add anything else to prevent the carbon from leaving?

4. i have copious amounts of epk clay, should i mix this up and seal the top of the crucibles with it?

 

i will have more, but caps game has started, and i am at the stadium.

 

-josh

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It's a little late to be asking fundamental questions without having any practice, for a burn Friday evening. I'll do my best to help, though:

 

1) Probably not, but it's best if you can "roast" them at a lower temp than melting, just a thousand degrees, to cook off anything besides the clay and graphite (assuming you're using those type). I've seen them run raw before without issue, so this is just repeating what I've heard as the ideal case.

 

2) See above - what are you using for a furnace that you don't have at home? "seasoning" doesn't mean adding anything to them, just getting them hot. You can do it in your forge if you have to, just ramp up and down slowly, don't cast it into a full-temp furnace cold.

 

3) Glass isn't about preserving C, it's about keeping O2 out. The clay-graphite crucibles will donate some C to the mix as well, there's no math I can offer but don't mix a "perfect" chemistry of ingredients and then be surprised when it's higher C than you planned.

 

4) No need, and not useful if you're doing it hot and fast like you saw Jeff perform - you want to be able to poke in there and check for full liquid before ramping it down and cutting off the gas. Same thing for killing it, you need a way to get in.

 

Most of this sounds like watching a modern method, but having read a lot of historical documentation. Don't conflate the two, just getting a molten ingot is hard enough sometimes, depending on what you're charging the crucible with. Trying to do it with old-fashioned technique without a really good grasp of the process based on experience is going to make life hard and expensive, fast.

 

 

If the guild is interested in watching a demonstration-scale smelt in person, I'm running one Saturday at the Claude Moore Colonial Farm just up the road. $8 a ticket, and we're doing it in period clothing and props (cheat the electric blower in, though). That would give them a perfect example of what it entails, I do it 3 times a year on the farm for their Market Fair events, and am happy to discuss the process with them. I'll be getting ready for that Friday evening, else I'd slip on over to the guild and watch your thing.

 

Good luck. You should have my contact info if you need it.

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