Table Top Kilns

[Ballistics in Scotland]

I bought a very cheap Chinese kiln on eBay, and it might have been fine for some purposes. But the element blew as soon as I tried for the maximum temperature which was claimed. I think the electronic controller was reliable, but I found the fragments of wire were hardened, which suggests that it was nichrome, which fails at a lower, temperature than kanthal.

About all I know about electricity is that I've never seen any, but it exists anyway, lurking in there and ready to jump out ajobnd zap you. But I found a most helpful seller of kanthal wire on eBay, who advised me on the diameter and length to duplicate the original 750 watts. The wire coils ran in open grooves in the rather soft insulating material, novaculite probably, which I didn't much like, but was handy for that job.

Later I bought one of these, used 5on eBay, for about $250:

https://www.efcocreative.com/efco-ki...30-v-1200.html th

The interior is one-piece ceramic, with the element concealed, which is a lot easier to clean. It only has an old-fashioned dial control, but a hole through which a thermocouple or digital thermometer could be inserted. The interior is only about six inches square, but you can do a lot with that.

I also have the ambition to make a Japanese sword and Renaissance-style rapier, which is nearly impossible to harden and temper straight by any process we know today. It would have to be hung and immersed vertically. I have the large kanthal element, an electronic controller and 5/16in. titanium rod for connections that won't melt. What I need is a large fireclay pipe, such as used to base used for drains but has long since been replIaced by plastic. I know of an unused piece in the old quarry buildings on an uninhabited island, where there are boat trips in summer. I'll have to check with the owners, but I am pretty sure they will say "Just take it."

[GONRA]

GONRA suggests Brownells for a small electric heat treat furnace and related goodies.
Bought one for heat treating "gas furnace" hardened parts
but still hava looong way to go climbing the learning curve.

(Did a lot of heat treating cutters, small parts asa kid on Parent's Basement Gas Plate.)

[clodhopper]

Ballistics in Scotland,
Maybe a chimney flue liner is what you need for heat treating swords.https://www.google.com/search?q=chim...4mLqngLFcKE6M:

[GONRA]

GONRA thought is was small GUN PARTS, not Great Big Swords! Sorry...

[Ballistics in Scotland]

Nice colour, but thin, and the colour looks like terra-cotta or a mixture. A domestic flue doesn't need as high a temperature as hardening of steel requires. I have seen terracotta recommended for a working temperature of 600 centigrade, or withstanding a soot fire at 1000. That is an occasional event, and about equals the hardening temperature for A2 air hardening steel. I do know of some, expensive and perhaps available only in Germany, which are of the proper fireclay colour and are claimed to be usable at 1250 centigrade.