Heat Treating Oven. Fixing my Mistakes

If you have watched my other videos about building my heat treating oven, you need to watch this too. This is one is highlighting the things I did wrong which I don't want you to get wrong as well. So please watch this in conjunction with the other videos. Thanks.

[@tomsmith3045]

Love this. I've not seen anyone put a mica window in an oven, and that's a great idea.

[@djpenton779]

IVery interesting. Also, refreshing to see a video about fixing mistakes! My kiln is at the design stage, so this is useful. I now intend to make the steel frame so that it can be dismantled for doing repairs - some welding but also some bolts. Thanks!

[@davidmcminn1843]

Hi. I'm in the planning stage of my own HT Kiln and found this was very helpful! Cheers :)

[@alanspeert8351]

Thank you it's hard to admit mistakes but you have saved me from making them myself

[@Ukenick]

Alan, thank you so much. This is what my channel is all about I will always admit my mistakes so we can learn together. I really appreciate you comment

[@JimmysCanal]

I can't think of anything better than admitting the mistakes we can make, admitting our mistakes puts us right in the middle of the road to correcting them. In this case you are helping many on saving time and money. I'm happy to see that everything went well and the oven is working properly! Well done my friend, well done! Dimitris

[@Ukenick]

Thank you Dimitris. I am really pleased with how it is working now. You have been a huge help. So grateful.

[@thomcarr7021]

Your mistakes (explained) are someone elses success.

[@garrydeimert7397]

At last, you have explained the black magic that is electrickory in a way I can relate to, now I can buy my wire with confidence. Thank you my friend, you have a great teaching manner. Good luck with your projects. Liked and subbed.

[@Fishy1764]

Brilliant idea putting the window in great video loved it mate.😊👍

[@Ukenick]

Sadly the window didn’t work out. The heat made it opaque in time. Will try and replace it with something tougher when I have time. But thanks so much for your support

[@MrMarsBlades]

Hey mate, hello from Perth Australia, I see this vid is a bit old now, but thought i'd make a comment anyway. I have a knifemaking channel and currently do my heat treating with gas which is ok ...up to a point. I plan to make an electric oven and watched quite a lot of guys doing so. I much prefer the vids with warts an all as we learn so much more, let's face it we all make mistatkes. Thanks for making the watts, amps, ohms calcs seem so simple. Will backtrack and watch your build from scratch, cheers mate.

[@howder1951]

Very interesting and enjoyable to watch. Stan Zinkowsky at Bar Z manufactured hot shot ovens from scratch, and documented the same on you tube. Very similar to your endeavours , just thought i'd give it a mention, in case you'd like to compare notes as the project is very similar. Anyhow, thanks and cheers!

[@ianlee7782]

Thank you so much, I have wanted to build one of these myself and you have given me the inspiration, I like the way you have added the peep hole and I have designed that into my kiln. You didn’t make mistakes, you make improvements the middle 2 is always better than the mark 1 take care and stay safe and again thank you.

[@Ukenick]

Thanks so much Ian. Just a heads up. Don’t use Mica for the peep hole. It degenerates quite quickly. Look into other options maybe. Good luck with it all. I am loving mine now.

[@dariostino]

We should all chip in and buy this man a couple of cartons of beer for saving us money and time building our kiln!!

[@Ukenick]

I would gladly accept. Thanks for the note. take care and good luck.

[@microsaj]

Thanks ever so much. I really appreciate your live approach in the videos, showing mistakes and their solution is really useful to others. Maybe I missed some videos, but have not seen this elsewhere. Question on liquid glass and Kanthal: is it the sodium silicate that attacks the wire? I'm thinking of other ways to coat the walls, to add an IR reflector.

[@markopraha4763]

Thank you! its very helpful :)

[@danstearns1221]

Howdy! I'm just starting to build my oven. I wanted to do a peep hole, but was not sure how well it would work. Seems to be working for you. Great video.

[@Ukenick]

I am so sorry its taken me so long to reply. I miss some comments sometimes. The peep hole is a great idea but to be honest I would use high temp glass over the crystal glass I used. It just goes opaque in time and now I can't see anything through it. Having said that, when I build my next oven or remake the door, I will def have some sort of peephole in it.

[@george5988]

Very nice video! I making one similar with yours but at 2000-2200W with 0,8 canthal. I think its ok. And work without problem with electricity from home. Here in Greece we have 230V.

[@samuraidriver4x4]

I like the peephole in the door, half way tempted to rebuild mine now. I am waiting on the pid to finish my build. Vegoilguy here on KZbin has a easy to use calculator on his website if you are bad at math like me. Just enter the basic specs like voltage, wanted amps and resistence of the wire and it gives you the exact wire length needed.

[@Ukenick]

Johan, if you are the same Johan who helped my in the forum, I am very very grateful to you. Thanks so much.

[@samuraidriver4x4]

No it's not the same johan as from the forum, might have commented on one of the build videos here on youtube though.

[@basirheydari4177]

Hi, good time, I had a question if I wanted to build a 500 degree Celsius furnace, I have to put some elements on the side.

[@TheRik18]

Just watched the full build! great videos and just what ive been looking for. Did the 1mm kanthal work better than the 0.8mm ? i cant seem to find anything more than 0.8mm in the UK at the moment!

[@Ukenick]

Hi Ricky, thanks so much for those kind words. I strongly urge you to find the 1mm. the 0.8 burns out. If you use the formula I show, you shouldn't go wrong. I'll try and hunt out where I bought mine, but can't promise as I bought a big spool which has lasted me a while.

[@TheRik18]

@@Ukenick Thats brilliant thank you very much ! I can import but seemed to double the price, its my first hurdle in this project. Did your thermocouple issues resolve in the end ? Really enjoyed the videos, looking forward to watching some more !

[@davidhawley1132]

In their "Kanthal Handbook: Resistance Heating Alloys and Systems for Industrial Furnaces", Kanthal talks about something called surface loading (how much energy the wire needs to withstand). For A-1, you want to keep it around 2.5 W / cm^2 or lower. You can calculate by watts / ( pi*wire_diameter * wire_length). The other design parameter you have available is to wire N segments of wire in parallel. Using two segments results in each segment using 1/2 (=1/N) the wattage, needing the required resistance thus as a result needing twice (=N times) the wire length. But as a result the surface load is lowered by a factor of 4 (=N squared). Unsuprisingly, total wire length is quadrupled (=N squared). Similarly for three segments etc..

[@adamdiaz8442]

You say you want 3000watts but if u had 32amp supply would the wire still melt?@6000watt

[@pbkeftensaljum1649]

Sir please help me. I live in Indonesia. I've got my element made from stainless steel304 1mm thickness. It has resistance 20 ohm. Similar with kantal. Kanthal 1mm is very rare here. My electricity supply is 220Volt. The problem is, it is very hard to heat up until the quenching temperature. It takes 1,5 hours just to reach 500°C. Why is that sir? Appreciate your sharing

[@fernandoamerico1996]

Ótima explicação, parabéns Aqui, Fernando, cuteleiro do Brasil

[@Ukenick]

Muito obrigado amigo.

[@fernandoamerico1996]

Eu que agradeço pelo seu empenho em explicar tudo muito bem Um abraço meu amigo Qualquer coisa, é só chamar

[@rabbitholejunkies]

Can you explain where you put the thermocouple the first time that was wrong and the second time that was "right"?

[@Ukenick]

Hi there, in the construction video I placed the thermocouple at the top of the oven looking down. Many people told me it was best at the bottom near where the blades will be to more accurate. I confess, I am not absolutely convinced it makes that much difference in an oven this small and also its a little more annoying as it gets in the way of what you place in the oven. Anyway, hope that answers your question.

[@looklearn9711]

Seems like your oven could use a fuse or circuit breaker of some sort.

[@fishoil2158]

You needed to see the metal but you don't need a light? I bet you can use the same trick with the mica to get a lamp in there.

[@garrydeimert7397]

Just noticed that you have 1 layer of bricks, is that enough and how hot do they get on the outside, most do two layers but I'm a cheapskate.

[@Ukenick]

Hi Garry. For the size of my oven, single layer bricks are working fine. they do get hot, but not dangerously. To be honest though, the next one I build will be double walled. Firstly because I would like a slightly bigger oven and also I am conscious of the heat that I am wasting through the bricks. My guide would be: light use, small oven, single brick. Consistant use, bigger oven, double brick. Good luck

[@valdolandar534]

I do not understand why you have rejected the 0.8mm cable, with this you can reach the ohms you would like to achieve, the same with the 1mm. What are the pros and cons of using the same ohms? Thank you in advance.

[@davidhawley1132]

In their "Kanthal Handbook: Resistance Heating Alloys and Systems for Industrial Furnaces", Kanthal talks about something called surface loading (how much energy the wire needs to withstand). For A-1, you want to keep it around 2.5 W / cm^2 or lower. You can calculate by watts / ( pi*wire_diameter * wire_length).

[@romankhan9313]

how 1mm wire can produce higher temperatures than 800c with 13amp current? in Google web nicrome wire calculator show some 20-25amp need to produce that level temperature,can you explain this?

[@Ukenick]

Hi, I'm afraid I can't remember all the calculations now, but I think I explain the formula in the video. It is linked to the length of wire you use as that alters the resistance and hence the heat. I can assure you that my oven reaches 1200C but I haven't tried it higher and don't intend to. Hope this helps a bit.