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Furnace Building

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Ok, i thought someone out there might want to laugh at my feeble attempts at making a tempering furnace for swords.


I havent finished it as yet, so it might not actually work by the end... :D

but if nothing else, it will prove to be a warning for others.


Speaking of which:

I am NOT an electrician.

I am NOT a welder

I AM able to build things with a total disregard of logic and common sense ...


i have a healthy respect for anything within my workshop and its ability to mame, kill and destroy.

this includes electricity.

in fact, it REALLY includes electricity ... because its something i just cant see .. and is way too technical for me to understand 100%.


Thats why i got someone who does know about electricity to put together the element etc for me.


i managed to find a supplier of fire bricks ... went down... picked them up .. got home all eager to start building .. only to find that they hadnt given me what i wanted and i then had to call up and argue lots before i was given a refund.

i then found a much nicer supplier who provided me with the Right grade of bricks.

Those would be type 23 insulating fire bricks.

my supplier sold them by the box .. in lots of 8 ..

so i got more than i wanted, but i figure that i will more than likely break several .. and would probably regret not having the spares if i didnt have them.




the main advantage of using these bricks is that they are softish chalky type things and they can be cut and shaped by use of a file and hacksaw.

(best to borrow someone elses tho ... you dont want to use your best jewellers files on these things)


((and the kick bag is good for when things dont work well and you need to get rid of some built up frustration :P))


I got some scrap bits of angle iron .. and some bits of scrap tubular metal (im cheap).. and figured a rough idea on how to put them together to support the bricks.

It was tempting to use something more substantial for the frame ... (i tend to build Frankenstein type machines with hugely over supported frame) ... but i just didnt want the extra weight.

so i went with bare minimum.




ive figured on making it as a flip top lid ..

so .. i started from the top and am working down.





i havent pinned the bricks onto the lid... mostly they are held in there by a tight fit of the metal shell .. but i might anchor them better once everything is together.

just want to see how it is when i try to lift the lid.


i got the base planned out ..

the tubular metal provides a nice strong point that ill be able to attach a hinge to allow for the lid to move.

and the angle iron just keeps everything tight and together.

and numbered all the bricks so as to make sure that i could get it all back together again later on once the channels were cut for the element.






i made a very technical tool out of some scrap round piping that was about the diameter that i wanted the channel to be cut .. :P

basically its self explanatory ... a pipe with slots cut into it and then the remaining metal hit with a hammer to unshape the roundness of the pipe.




i then kitted up with my respirator on extra tight (including my ipod compatible ear protection) and went to work at scraping a channel into the bricks.




using the scraper on the bricks worked pretty well at cutting a channel .. but it made a hell of a squeaking noise as it did it .. and made a whole pile of fire brick dust.






after i was done with that one side .. i gave up on that and started in on the electrics part of it all.

now ... im working this for My power system .. and im working off of the diagram that was supplied to me by an electrician who deals with kilns etc.

so ... im not going to go through what i connected to what until i know for sure that it works.


but at the end of it, this unit will be attached to the side of the furnace and will hopefully control the temperature.




tomorrow ill get the other channel done ..

and will be able to hopefully stretch out the element without breaking it ..

and will go about putting it all together and TESTING ... :o



now.....stop laughing.

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Very nice! Power to you, and I don't mean the electical sort. :lol:


Most of the plans for these things I've seen indicate that the elements will be live when there's power flowing, as in will zap you if touched with a blade when the furnace is on, so do be careful!


I'm jealous, by the way. :P One of these days I'll build one too.

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Sweet. Makes me feel guilty that I've been sitting on a bunch of electronics, resistance wire and such for so darned long. Need to get moving on that.


I don't know if it's necessary or not, but I have a heat exchanger for my SSR. Just a thought. Are you going to have a manual on/off switch in addition to the PID? This goes to the safety issue Alan mentioned. It's really good to be able to power it down completely before you insert or remove a piece of steel.

Edited by Matt Bower
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Nice work Dee. Building your own equipment is half the fun of blacksmithing/bladesmithing.



A side note, I think my parents have the same style rocking chair as you do :P

Bob O


"When I raise my flashing sword, and my hand takes hold on judgment, I will take vengeance upon mine enemies, and I will repay those who haze me. Oh, Lord, raise me to Thy right hand and count me among Thy saints."


My Website

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Just to add to the safety notes, you really should mount the SSR on a heatsink and install a cover on its wiring contacts. You might want to find an aluminum enclosure for the PID/SSR/electrical that is a little more heavy duty and large enough to hold everything. Nothing like smelling, then seeing plastic on fire to make you realize its too late to fix! :wacko: Go with your Frankenstein instinct for the electrical control box and you'll be fine :lol:


edit: electricity and metal need proper spacing between connection points, but it won't melt/burn when mounted against the side of the oven ^_^

Edited by Mike Barton


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very cool...... wish my kiln was that big.....

All these things shall love do unto you that you may know the secrets of your heart,and in that knowledge become a fragment of Life's heart...

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Looks like you know what your doing ;) and making a good job of it :D . Have fun and let us know how it works.




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Very cool, I look forward to seeing it finished up.


I could build something like that as well, but like you the wiring would have me lost.


Yes you do need to build one Alan, especially since she said this one should reach critical temp. The haunting guard of guilt is watching you!

Beau Erwin


Custom knives

Bcarta Composites

Stabilized Woods

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Thanks guys.



ok .. to answer various questions ..

no, im not going to have a cutoff switch.

mainly because its something that i dont know how to actually wire up properly.


i have 2 other kilns that i use for casting and enamelling in my jewellery.

and one of them (the smaller) has already zapped me in the past when the element 'leaked' through the refractory.

its a Kerr kiln .. and the way they do their elements is pretty silly really ..

they are supposed to be totally sealed in order to allow for safety .. but mine managed to still zap me good.


i reached in with my tong things .. grabbed the pot of investment and the tongs arced to the wall and pow... felt like someone punched me in the chest.

didnt know what the heck happened for a while... thought that my workshop had suddenly become haunted or something.


anyhow ... since then i have gotten the kiln re-wired and modified and the kiln guys told me to get one of the cut off switches to plug into the wall .. as well as get one that will work back at the power box.


so .. thats what i plan to also use on this furnace.

plus, i also have a routine that i use .. turning off the kiln at the power source before opening them.

so im going with what i know and seeing how i do.


Bob O~ that rocking chair rocks .. umm .. no pun intended. :P

it was my mums .. and in between heats at the forge ... you cant beat being able to sit back and rock your little heart out.


Mr Barton~ thanks for the advice.

the reason the SSR is out is because i dont trust the built in heat sink that this one came with... so i wanted to go through and find a heat sink and mount it along with it.

i figure that with all my obsolete computer stuffs about the place, i should be able to find a good strong heat sink that will work.


i might have to go and get another box.

i just liked this one because its a banks strong box that is heat/fire resistant. :D


Bob M~ if it looks like that .. then theres something wrong .. lol



Mr Fogg~ no problem. i just have to remember to take pics as i work .. i keep forgetting ive got the camera there with me :)


Greg~ swords have always been on the menu ..

i have a sword length gas forge that i use for quenching ..

but ive never had a way to actually temper them.

in the past ive just been placing them back into the forge after its shut off and letting them temper from the residual radiant heat.

bu its not what i would call precise.

so it bugged me.


i have an order that has been hanging over my head for a while.

and not only is it meant to look all pretty, but its also supposed to be able to be used for tamashigiri, so im wanting to make 110% sure that the katana and wakazashi in the set will actually be tempered to the right level that i want/require.


plus i used to do a lot of heat treating for the local reenactment club that i was a part of.

it was a great way for me to test whether or not my heat treating was really up to scratch .. because we would smack swords together or against shields pretty roughly ..

any small flaw and the blades tended to ping


though mine never pinged, i was always wanting a way that i could do a couple swords at a time .. rather than having to do each, one by one.


today will hopefully see quite a bit more done.

all i seem to do lately is build machines and not blades. :)


i need to figure on a way to lock the door to the frame.

plus i need to figure on where is the best place to stick the thermocouple.

i have gone with a ceramic coated K type TS, and im thinking that the middle somewhere would be an idea.

i just dont want to end up with lots of drill holes all over the place while i think of where to stick things. :)


and then i need to figure where the heck to place this monster in my workshop.

im so very running out of room in this new place its just not funny. :)


i want it near my sword quench pot, but not close enough that it will get near the sword forge.


... oh, and i need to figure on what to name it. ;)


ok, more pics tonight.


thanks for looking guys.

and thanks for the advice.



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Sweet furnace Dee, I dig the bomb proof ear protection, I don't know about Ipod they look atrack compatible :D

Edited by Sam Salvati

Let not the swords of good and free men be reforged into plowshares, but may they rest in a place of honor; ready, well oiled and God willing unused. For if the price of peace becomes licking the boots of tyrants, then "To Arms!" I say, and may the fortunes of war smile upon patriots

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i loves my bullant earmuffs :D

they have great ear protection .. plus they have an inline jack attached to them so i can listen to music while i forge in perfect clarity.



when it comes to protection equipment ... ill forget my dust mask sometimes ... ill forget to turn on my extractor fan .. ill forget to put on my face shield .. but there is no way you will have me forgetting my hearing protection. :)


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when it comes to protection equipment ... ill forget my dust mask sometimes ... ill forget to turn on my extractor fan .. ill forget to put on my face shield .. but there is no way you will have me forgetting my hearing protection. :)


Agreed. Someone had mentioned also that when you have hearing protection, you are able to forge more readily because the sound from the anvil/hammer/steel makes you cringe for a split second before/during each hit, so when you have some hearing muffs on you can hit a touch harder. never tried it though..... -_-

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Let not the swords of good and free men be reforged into plowshares, but may they rest in a place of honor; ready, well oiled and God willing unused. For if the price of peace becomes licking the boots of tyrants, then "To Arms!" I say, and may the fortunes of war smile upon patriots

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now.....stop laughing.


No one laughing here Dee, you have your act together and have certainly put some thought into it.



Agreed. Someone had mentioned also that when you have hearing protection, you are able to forge more readily because the sound from the anvil/hammer/steel makes you cringe for a split second before/during each hit, so when you have some hearing muffs on you can hit a touch harder. never tried it though..... -_-


That makes sense - the same thing happens when shooting, you get to anticipating the recoil and the noise and you start flinching and your aim suffers because of it.

Once you can accept the universe as matter expanding into nothing that is something, wearing stripes with plaid comes easy.

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Hey Dee,


You're most welcome for the little bit of fine tuning advice I have to offer. It seems you've already been given the best training available for working with electrical devices-ZZZZZZZZZZZZZZZAP!! :o Keep posting more pics, you've got a great WIP thread going!


By the way I'm Mike :D , My Dad is Mr. Barton :P


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Cool thread Dee, thanks for all the photos, pls add as you can. I have a scrap pottery kiln and loose bricks that i hope to turn into smithing tools so your post is very helpful. Aloha, Steve

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Awesome Dee!

My life is like shaving with a razor sharp machete. It's a bit awkward and I feel a sting every now and then, but in the end I'm happy with the results.

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yes, i wear glasses.


stupid things that they are.

usually i wear contacts ... but contacts and brick dust is just plain silly.


i havent gotten any more pics as yet .. because when i went to do some more to it the other day i saw that they people didnt send me the hook up wire that i needed ..

so i had to find a local supplier and make a trip out to get the stupid things.


i also need to make a trip out today in order to get a 20 amp plug.

but i should have some more pics to show you soon enough.


thanks for watching.


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I have some more work that needs to go up on it soon ...

just need to get one thing done at a time. :)

but im glad you like it.


ok then ..


well a lot of yesterday was wasted running about the place trying to find parts.


i dont like going out ... i usually waste a whole day trying to get just a couple things.

plus, i tend to buy stuff thats not on the list at the same time :D


though yesterday was only a neon yellow finger nail polish ... but geez .. it was soooo kewl .. and only $1 .. :D

how could i pass it up??


ahem ..


annnnnyhow ..

i managed to pick up some more 20amp wire .. plus i got a 20 amp plug for it all .. a good hefty one ..

and a wall socket too ..

this was an adventure in itself ..

i had assumed that the local store would have the plugs i needed ... instead they had none .. but one of their other stores that was miles away had 8 of them .. ??

drove all the way up there only to be told that they had none ...

phone calls and arguments ensued and someone found them hidden away somewhere.



anyhow .. ive managed to sort out the insulated wire among it all ..

and also some glass fibre rope to be installed to create a seal around the top a little nicer.


i got the rope even though there isnt much of a gap ... its only about the thickness of the metal holding the bricks together actually ... which is about 1.6mm

but still ... i want the heat to stay inside ... plus i like the idea of the heat only touching the bricks.

call me paranoid.


now ... all the channels have been cut into the bricks .. all filed out with the pipe and such .. and they match up as i wanted.


i used a masonry bit to drill a hole in the end caps

to allow a piece of stainless road to pass through the ends.




why? ... simple.

its going to be supporting the ceramic rods that will be supporting the element.

there are a couple ways to install the element ...

a common one is to place it inside the channel thats been cut and then use small clips of wire to hold the element in.

my enameling kiln has that kind of setup, but with these large elements i wanted something more secure.


so.. i had them send me large ceramic rods that would go inside the element coils ..

but they didnt send enough.


so i drove out to get some more at a local place ... to find out that the difference in cost was HUGE!

the difference was about $120 between the two suppliers.

pays to shop around obviously.


so, instead of having to go through all of that ... what ive done is taken some of the left over bricks and ive drilled a hole through them and shaped them to the size i wanted for the supports.

ive cemented them together with a bunch of fire cement stuff and then sanded them back ..

ive waited a while for it to dry out and will be sanding them back again.




the element was supplied coiled tight .. and needs to be stretched out before placement ..

so i wrapped a bunch of hard cloth around one end and placed it in a vice loosely .. and then took small sections and stretched it out slowly and carefully ..


you dont want to clamp down on the wire too tightly or you might damage the element ...

and id advise being really careful with this ... im not sure how strong the elements are ... but they sure can be springy .. and metal snapping and springing back in your face is never nice.




so ... now i have supports for my elements ... a stretched out element ... and holes for the stainless rods to go through ..

i drilled two holes for where the element will come out of the brickwork .. and placed two smaller ceramic rods inside.

i need to construct the housing for where the elements come out still .. so that there is nothing exposed.. but we will get to that today.






oh... and ive also added a little rest on the side for the electrics housing.


with any luck it will all be finished up today and ready to go by tonight.



more pics to come laters.


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