Finally. Seen a video.. stated it’s purpose in title.. showed a great way to DIY said product. No frills no BS. And accomplished this perfection without having to listen to some tool who just loves the sound of his own voice blab on about why he decided to bless us with his idea. Thank you kind sir.
@richg04043 жыл бұрын
And no annoying music.
@incorporeal37934 жыл бұрын
It is very satisfying to watch something like that being made to suit someone's own needs.
@tacllemtacllem76794 жыл бұрын
OMG your plate to stop the crucible from falling out while pouring is Genius. I have been contemplating this complicated slide arm thing.
@GlueTubber4 жыл бұрын
Nicely done! I've got a washing-machine barrel that I've been holding onto for a while, now that I've seen how you finished yours I know what I need to do to finish mine!
@sdavifcom4 жыл бұрын
The quality of your work and your creativeness do not cease to amaze me. Your videos are some of the very best on KZbin all categories combined.
@percival234 жыл бұрын
Your lid, and the 2 crucible holders you use is by far the least stressful set up I have seen. Well done.
@IdeaShip4 жыл бұрын
Your creative potential seems limitless.
@johnallen868011 ай бұрын
Apart from him not removing the original blue paint before putting on the high temp coating this is a perfect project. The best yet that I have seen , especially if like me you have a workshop to store a large heavy furnace . I too was contemplating just buying a lightweight one from vevor, but after seeing this I now want to copy it.. Also I have the tools and welding gear, but not much cash to splash as I've just retired. Building my own I can do a bit at a time and build it over a few months instead of having to pay out a big lump of cash to buy the Vevor. Also, this self build is bigger , far more robust and will have a much longer life. Great project, well done ! 😊
@jakestarr47182 ай бұрын
that insulator is like 6" deep, the outside will never get hot but that refractory cement will chip into the crucible over time. Its best to just use 1500 C ceramic insulator without cement.
@DH-mw7pe4 жыл бұрын
Pro tip: when using concrete and forms put either axle grease or diesel fuel on the forms where you don't want the concrete to stick. Note: colored axle grease will stain concrete.
@1TUFZ713 жыл бұрын
So a light layer of diesel on the bucket before cementing? Good to know, thank you!
@kevinh68533 жыл бұрын
We used to coat metal wall forums with a mixture of kerosene and diesel fuel so the concrete wouldn't stick to em.
@Skinflaps_Meatslapper3 жыл бұрын
Yep, the kerosene/diesel mix is pretty common in construction as a release agent. But really, anything greasy or oily that doesn't evaporate or wick into the concrete (don't used water based stuff) will likely result in success for a DIY project. Just be sure to use something expendable, non-porous, and preferably with a smooth finish that doesn't have an odd shape (like a coke bottle or something), because not even a release agent will work well enough to get some things out...that's where the expendable part comes in LOL
@n00bkill3 жыл бұрын
Just use furniture polish, it's convenient and low mess.
@CIA_Alien2 жыл бұрын
@@1TUFZ71 No... He's an idiot. Never use a combustible material at any point during this sort of process.
@ShamankingZuty4 жыл бұрын
That had to be one of the cleanest looking furnaces I've ever seen. Great work.
@steelforcellc2 жыл бұрын
Absolutely , Wonderful
@edimahler4 жыл бұрын
Unbelievably cool, thank you for sharing this! ...and thanks for not adding disturbing music in the background, it's just perfect like this. Highly appreciate this...
@exidy-yt4 жыл бұрын
Excellent work, and excellent video showing us only the work and not filled with a bunch of distracting music or narration that wasn't needed. Consider me a fan, if all your videos are like this!
@DYLANTRIES3 жыл бұрын
A year later I watching this again and still am amazed on how well you did this! Most just use wool and call it done you went all the way and did it perfect!
@HandToolRescue4 жыл бұрын
I need to do this.
@candydavis94104 жыл бұрын
We made one but smaller..
@heyimamaker4 жыл бұрын
Alternate channel Hand Tool Meltdown
@Avocadomushroom4 жыл бұрын
Yeeees 🙌🏻 I’ll for sure watch it 🙂
@teachingisthebestwayforyou40644 жыл бұрын
I need sir new please send your address
@moisesojeda56474 жыл бұрын
@@candydavis9410 same process?
@toolscrounge4 жыл бұрын
I have a commercially produced, industrial grade furnace similar to this and it’s a great design. You can throw an electric blower on it as well and it’ll get your temps higher (mine has one built in). Look forward to seeing what you cast in one this size!
@zelmo994 жыл бұрын
I made this and it ended up perfect all thanks to you! Great build....NOW the disclaimer LOL I installed casters under also like you and when I swung the lid the forge about tipped over from the lids weight, so I installed an axle at the rear. Also I made a 2nd handle mounted to bottom drum so I could steer it vs the movable lid trying to move it around didn't work so well for me. Thanks again!!
@YKW794 жыл бұрын
I've built at least 5 foundries till now. And I can confidently say that I'm about to build the 6th one. Like, holy shit. This is PERFECTION
@jmadventures98303 жыл бұрын
what type metal that's inside the furnace that's used to heat the other metal, the one that doesn't melt ????
@agriculturemachinerychanne95743 жыл бұрын
@@jmadventures9830 it's called crucible...it is made of porcelain or any other inert metal which can able to withstand high temperatures..
@jmadventures98303 жыл бұрын
@@agriculturemachinerychanne9574 thanks I figured it out eventually... did you build a foundry ?
@agriculturemachinerychanne95743 жыл бұрын
@@jmadventures9830 no
@hajii1242 жыл бұрын
If youre using concrete or motar and you plan to use pipes like he used for the gases, dip the pipes into used motor oil. The oil prevents the concrete/motar from sticking to the pipe. When making sewer lines and manholes, we use 1 part deisel fuel and 3 parts oil for the ladders and holes for various pipes that are mapped into the concrete during pour
@Gogsnik4 жыл бұрын
I'm always really impressed that the homemade workshop tools and gadgets always look so professional and neat. Another great video!
@finddeniro2 жыл бұрын
Signed Edison.
@mwk50423 жыл бұрын
Damn, I love people's ingenuity sometimes. That angle grinder on a plywood fixture and using your microwave for the height...genius. lol. Made my day! Great stuff!
@olliefs92984 жыл бұрын
This is by far the best DIY furnace I have seen yet... and I think it's the one I'm going to try replicate!! Really love the crucible tongs and pourers too!! Great vid thanks :) Edit: also great idea on cutting the drum!!
@agri-lifeorganicfarm24664 жыл бұрын
Good video but it would have been more useful if you had explained mostly what materials and receipt you used like in the cement. Where did you get the fiberglass or wool insulation?
@СергейЛебеденко-у6ю4 жыл бұрын
Old blue coat must be deleted before using themostable paint. It's cool crucible furnace. Sorry for my English.
@topc58264 жыл бұрын
Yeah, I see your point, the old blue paint coating might just turn to ash but hopefully all that insulation he put between it and his furnace center will protect it and the paint on top from turning to ash.
@sergeykulikov42074 жыл бұрын
no need to apologize.. and yes, such thermoresistant paints strongly reccomend to remove old paint and even not to use primer coat
@busybee68894 жыл бұрын
im tippin he took that into account...he's no dumb bunny you paint Nazis
@m3chanist4 жыл бұрын
@@busybee6889 He plainly didn’t, otherwise he'd have known to remove it. Only the insecure can't cope with constructive criticism, always right non learners
@jakestarr47182 ай бұрын
apparently you don't know how strong 1" of that insulator is and there is 6 inches total with a 1" very high temp ceramic insulator inside. The entire problem is the cement, the can will NEVER get hot. The thermo paint will resist spills on it, but that cement will chip and it will get into the crucible. You can use graphite mixed with refractory cement like heat stop that's rated for 3000 F and turn the entire thing in to a hard packed crucible, just the bucket in center will need holes in the bottom to pull out; the problem is that it will still break down and the insulator is cheap by the roll at 2700 F... LMAO
@rojerww4 жыл бұрын
Nice - very nice. I left my furnace behind when I moved - it was well weathered. Considering a Devil's Forge, but may make a second from scratch instead. Your video reminds me of the fun it was to make my first one. Single port, forced air injection, charcoal powered - a bit slow, fully functional for aluminum. Yours looks faster, hotter, and perhaps easily copper and brass capable.
@Donorcyclist4 жыл бұрын
I'm always impressed at how you think in innovative ways to accomplish your goals. Very nice work!
@stephenjohnson6841 Жыл бұрын
Your ingenuity, engineering and execution of these projects is so inspiring! Thanks again!
@rileyandersen73463 жыл бұрын
I went from looking at a small easy to use electric metal furnace to some guy making his own gigantic one. That escalated quickly!
@Scandinavian_Pride2 жыл бұрын
Somebody knows their way around the fabrication shop! One of the best builds I've seen on KZbin in years! 💪👍
@ber5erker__7604 жыл бұрын
Can I just say that I love the fact that you used a microwave to make that cut at the perfect height 😂
@markowen71644 жыл бұрын
That's a great idea. I have tried to cut so many things like that. With a wibly wobly cut.
@darwinist2030 Жыл бұрын
Good luck servicing those castors.
@fabbrorandomlife3 жыл бұрын
This is the best diy design ever seen! Can you tell some melting time? It would also be great to have more info about that tongs!
@seanfoltz76454 жыл бұрын
Hands down the most impressive and sophisticated home job I've ever seen,
@ZombifiedWatermelon4 жыл бұрын
Good job man! That puts those store bought devil forges to shame! Can't wait to see what you melt in it!
@spiroketal70244 жыл бұрын
I've built a couple of forges and a furnace, some with home-made refractory, one with commercial materials. I'd just like to say that I can really appreciate your design and execution😊
@wehiird4 жыл бұрын
I feel so accomplished, and all I had to do was watch this and eat a sandwich. Great work
@pandapanda83544 жыл бұрын
VERY CLEVER! Yes. I am jealous. Your design is functional and so ergonomic. I love it
@PeachIceCreamy4 жыл бұрын
I love how he basically used his angle grinder as a can opener xD
@firesurfer4 жыл бұрын
I used a jackhammer to cut open 50 gallon drums all the time. I got quite good at it because I had to do it at least once a day at work for two years.
@FirstLast-yo5yf4 жыл бұрын
Yeah but I think you had enough
@gasd65423 жыл бұрын
Albeit an expensive can opener.
@poche66052 жыл бұрын
一一一
@gawags47094 жыл бұрын
Excellent build! I like the use of the venturi burners. No need for a power burner when you're just babysitting the thing until you're ready to pour.
@IR-nq4qv4 жыл бұрын
Awesome build, nice incorporated design using your dual gas ventures / burners which work very well. 👍👍👍
@MrFlyb4crawl3 жыл бұрын
This was one of the most entertaining videos I have ever watched! At first thought you were going to weld the handle that you spin open the lid with. A vibrator underneath the pan you pour the metal in may flatten out the shape at the top to make it smooth before it cools down too much and get the air bubbles out of the metal. I remember in my weld class for one semester we always had the slag on top of the metal and had to tap it with a hammer to break it off. All we did was weld some steel with oxycetaline torch and also weld a tool box we all made with a spot welder. We also got to arc weld a little bit. I was in electronics, but the one semester we had to take a class that involved some welding. That was one of the most enjoyable classes I was glad I took even though it was required for my associate degree in electronics. I loved all the forming you did using plastic and other materials until you got the desired outcome. I could see a 3D printer being used to create plastic molds for you to make other things out of cement as well and being able to remove the plastic.
@LarryGarfieldCrell4 жыл бұрын
All that to make cupcakes??? I salute you, sir!
@woodgemdave4 жыл бұрын
Great keeping the flame at the side to create swirl affect in the furnace, very efficient!
@anneinfurna85283 жыл бұрын
The Better way would be to aim the pipes at a downward angle toward the base of the crucible, and the fire would swirl around the crucible all the way up the crucible sides, and ends up with a more efficient heating pattern. I know it works as I have mine made like that and it gets 10 Pounds of red brass from cold metal to pouring temp in 1/2 an hour. Annnd I am using standard natural Gas.
@andrejohnson67314 жыл бұрын
What a smart build! I’m in awe 🤩
@Mesa8773 жыл бұрын
Thank you for showing how to properly and safely use kao wool. Too many videos showing unsealed kao wool being used. Nice build!
@muhammadrafayrizwan26914 жыл бұрын
I am really amazed how creative yet simple your designs are Keep it up Ps: big fan of your work 😍😍😍🤩
@610324dan4 жыл бұрын
please try to only use the bottom burner, just to see if the upper one makes any difference. maybe its located to close to the exhaust hole. I believe that the second burner should be placed at the same height but 180 degrees apart from the other one. it would be very very interesting to not only guess but know for sure
@xxportalxx.4 жыл бұрын
Given this and other designs I've seen the idea is that the heat actually blows around the inner vessel in a sort of vortex, given his insulation is any good it shouldn't make much of a difference actually
@610324dan4 жыл бұрын
@@xxportalxx. yes , but for a much shorter way than if it was located att the bottom. so I think it would be much more economical effective with both burners att the bottom
@xxportalxx.4 жыл бұрын
@@610324dan I think you're simply overestimating the locality of the heating, unlike a torch this oven has a body with insulation, the goal is to bring the chamber up to temperature, not just the focal point of the flame
@610324dan4 жыл бұрын
@@xxportalxx. but the longer the flame travel the more heat it leave inside the chamber
@markowen71644 жыл бұрын
I when I was a boy. Melted led in my mothers cooking pan's. Then she cooked my dinner and it. That could explain 🤔 a lot. M
@weregecko4 жыл бұрын
hey, i've always melted lead in my cooking pots, and i've never noticed a proboboboblem... wait, what were we talking about? am i actually typing at the moment? i thought i was at the beach
@au69miner4 жыл бұрын
@@myspace_forever now thats funny!!
@acescape884 жыл бұрын
That would explain your typing skills
@bacicinvatteneaca4 жыл бұрын
A reminder that ghettos in the us use a lot of lead paint, and lead poisoning has been shown to significantly increase aggression.
@canaan53374 жыл бұрын
@@bacicinvatteneaca the rest of the world banned lead based paint decades before the United States did, because rich people were making money and our law makers thought that was more important than public safty.
@elfowl68734 жыл бұрын
Very nice Furnace, BBP!!! it should serve you along time. Thanks for sharing.
@ScottClevelandmi4 жыл бұрын
Stick welder! About time some on on KZbin welds like the rest of us savages.
@TurinTuramber3 жыл бұрын
A stick welder can be perform to a very high standard... in the right hands.
@Buzzhumma4 жыл бұрын
Spot on but i do wonder how the top concrete will hold up over time . Maybe use the base of a 44 gallon drum with 50 mm of the sides still atached so as to keep integrity of concrete and also reflect heat downward. You could also line with so ceramic blanket before you pour the cement top! 👍🏻
@DieselsHOGVlog4 жыл бұрын
I was thinking that as well
@СергейБабайлов-щ6д4 жыл бұрын
Чем заливал? Неужели обычный цемент? Видео класс, Лайк однозначно.
да,плохо что не показывает материал из которого делал
@vodilaposuti4 жыл бұрын
Огнеупорный состав скорее всего, сейчас такой продаётся.
@hereyougoall7622 жыл бұрын
Excellent work you have done it is highly appreciated. What do you call this pot inwhich you melt the metals please mention the name of this and also upload a video on this pot how to make it.
@TheGoodoftheLand3 жыл бұрын
Awesome design! Definitely have to make one now!
@gongyius7363 жыл бұрын
Any updated?
@rirkc4 жыл бұрын
Another rock solid project by my favourite man-bun artiste. Thanks so much!
@gusser21214 жыл бұрын
Such a smart design! Did you do this or were the plans available from somewhere?
@shuvalassaf4 жыл бұрын
This design looks robust and strong, but performs very poor on containing and isolating the heat. I would not recommend it.
@literate-aside4 жыл бұрын
@@shuvalassaf And what's the reasoning for your assertion here? As at the moment it's entirely baseless.
@chrisjames63494 жыл бұрын
This is ok if you’re only planning on melting aluminium. I have a foundry made from an oil drum but use it for melting bronze. The problem with this design is there’s not much thermal insulation on the lid. I use a full size oil drum with 7.5cm of ceramic wool then coated in 5cm of refractory cement. I can use an A35 crucible easily with that setup and it only takes 2 hours to melt a full crucible. You’ll just have to work out what you’re going to be melting and work out what temperature you need before making it. I think the size of this is a bit over kill for the size of the crucible. That looks like an A12 maximum which I used to use with a small propane foundry which was only a fraction of that size.
@chrisjames63494 жыл бұрын
MrPhuct there’s no point spending way more money on map gas if you can do it with propane though. Also I’m really commenting on this being a smart design. It’s more of a waste of the oil drum. There’s way more insulation than is needed on the walls and not enough on the top. Plus it has a chipboard bottom. Even if it doesn’t burn it won’t last very long. If someone was going to make something similar I thing this is a poorly thought out design. You can get so much more out of an ‘oil drum’ foundry. It’s a waste of materials (expensive materials) to make something so big for such a little crucible. To melt that material you have to heat up so much thermal mass it becomes more expensive. For something like an A12 crucible (I assume that what it is from the video) all you need is 2 layers of ceramic wool in a mini oil drum (domestic frying oil drum) otherwise you’re just wasting fuel to heat something up that you’re not going to melt. I have made several oil drum foundries and use them daily and I have had to strike the right balance for fuel efficiency, size of my castings, material and usage costs.
@moisesojeda56474 жыл бұрын
@MrPhuct what do you think about devil forge furnaces, would it be a nice investment over making one of these? Im planning on melting bronze copper aluminum and thats about it
@SnorrioK3 жыл бұрын
I am amazed you got away with using so much water with the cement.
@StanislavG.4 жыл бұрын
Awesome build, man!
@frediusmaximus14 ай бұрын
Wow, very nice build. Do you build them to sell?
@shredct31184 жыл бұрын
That's Awesome, BackstackD Castings would be impressed.
@mans41043 жыл бұрын
This is the best furnace-making video, a lot of intelligence there.
@TysyTube4 жыл бұрын
🔥🔥🔥🔥👍
@shadybandit7PK4 жыл бұрын
hello
@rocketman98384 жыл бұрын
@@shadybandit7PK no
@jimfetzer9963 жыл бұрын
@@rocketman9838
@hassanabouabbass579010 ай бұрын
مرحبا ما هي المواد التي صبيت فيها القالب
@worshipman2 жыл бұрын
Hello, I have just a simple suggestion, to facilitate your work, concerning the big can, you can use a system as the glass plate in the microwave furnace, or something like this, as the same used for "ancient" televisions, all this, to cut the can with less efforts, knowing that it is really heavy. Sorry for my words, suggestion, and sorry for my bad english. Thank you for your comprehension.
@castsmith67834 жыл бұрын
Is it hot enough to make a crucible steel?
@windyhillfoundry59404 жыл бұрын
Great video 👌 but you may run into problems soon because you poured refractory directly onto a porous ceramic fiber blanket without sealing the surface first.
@Evolved_Skeptic4 жыл бұрын
Overall, this was a very impressive build. I'd like to see a breakdown of the materials used & the overall cost. Did you think to include temperature sensors & gauge for specific metals, or is this just for aluminium/copper recycling? Also, that pourer handle has to be one of the cleverest methods I've seen to hold & pour with a crucible full of molten metal. Most of the time it's a set of curved tongs that have to be held in an annoyingly awkward way with heavy gloves.
@solarflare88064 жыл бұрын
That was intense. Very professional, even better than professional.
@danhard84404 жыл бұрын
nice build brother cant WAIT to watch your big melts bigstacked step aside black beard comin through lol
@juancedeno7357 Жыл бұрын
I agree because is the best furnace Me encantó su trabajo mi amigo. God Blessed you
@voodoo70084 жыл бұрын
Nicely done, sir.
@VikingRhys3 жыл бұрын
Next time you are making a cast or mould using concrete or cement, cover the mould surface area with a thin layer of grease or thick oil, it will make extracting the mould much easier for you.
@WAdiS214 жыл бұрын
cant wait new videos with melting stuff
@coreymerrill32573 жыл бұрын
There is a hardening solution you can spray on the kaowool to make rigid and hold shape. If you don't want to buy refractory cement ,that's a potential solution. It may be good to use it anyway. Sandwhiching an untreated layer between an inner and outer layer of rigid wool would prove to be quite long lasting
@sp89574 жыл бұрын
Super idée je vais testé ca
@АндрейВинничук-в3у4 жыл бұрын
Very good work!!!
@michelemonti31473 жыл бұрын
Ottimo lavoro! Do you think that using this technique is possible to build a raku kiln? Is a furnace made with those materials suitable to temperatures up to 900/1000°C?
@theonlybuzz19694 жыл бұрын
Is there a specific microwave oven that I need to act as a height gauge for the levelling out the cut in the first clip, I really enjoyed watching this video and looking forward to seeing some more of your videos....Phil 🇬🇧
@inquizition96723 жыл бұрын
DIY videos like this are so inspirational. The deep sense of satisfaction and pride in your own handiwork is something money can't buy.
@slesarka_art4 жыл бұрын
Мощная печь !👍
@josue.carvalhooliveira48714 жыл бұрын
Fantástico. Meus parabéns. Vou copiar este forno que achei muito pratico e com baixo custo na construção. Minha dúvida é qual o tipo de argamassa?
@jasonamoscomedy4 жыл бұрын
Love to see you make gold or silver bullion some day - and then a secret treasure box to store it in :)
@bankotsu2a3 жыл бұрын
That jig to pour the metal is genius 👌
@BilalAhmed-jl5wc4 жыл бұрын
its really good love your vdz from Pakistan
@larryschweitzer49043 жыл бұрын
Nice work! My old melt furnace is getting in bad shape. I need to make one with better insulation. I want to melt brass & copper using old oil. Thanks for the ideas.
@hieronymus..bosch85324 жыл бұрын
I've had those muffins, they hurt the roof of my mouth
@jeffhaskin8953 жыл бұрын
most under-rated comment.
@slaplapdog4 жыл бұрын
The grinder jig alone makes this worth watching!
@artofroughhands61054 жыл бұрын
Что за жидкость ты наносил на ржавчину?
@МихаилПарфенов-я1д4 жыл бұрын
Преобразователь ржавчины с эффектом воронения
@surastyosamiaji21174 жыл бұрын
awesome, nice job Bro.... are you planning to cast engine block?
@wilmernorthman35184 жыл бұрын
nice video black beard projects
@talavs-jekabsriekstins5784 жыл бұрын
For insolation u can use starlaite material homemade, because this alumosilicate foam can cost much: for 1kg starlite there is 400g flour, 200g sugar, 200g corn starch, 200g baking soda, 40g borax. This guy uses cement that will eventually crack. Make a starlite paste by mixing all those 5 indigrients with water but dry it out of water before using furnace for a week or so. For more info check out starlite in youtube.
@sirtblairjr4 жыл бұрын
Hey Black Beard, you should wearing gloves with this project..ok..you know that😏 How much did this put back to make? And time?
@mds1986ms4 жыл бұрын
Gloves?! Must have a union man here. Lol
@jimanderson6994 жыл бұрын
Nice work. I Like the idea of the grinder on top of the stanchion for an all around level cut. Thank you.
@Crizisontopbaby4 жыл бұрын
Ohhh hot muffin guy again :D
@Remrie3 жыл бұрын
My objective design change to that would be to allow the insulation to be replaced. I'm pretty sure it breaks down over time and needs to be replaced like any other material, correct?
@djekvodogrei89054 жыл бұрын
Круто, люблю его ролики
@dukeshaver1993 жыл бұрын
What a brilliant way to make a forge. You are one smart cookie. Thanks for the bad ass video.
@alanday5255 Жыл бұрын
Whatever language that bottle is was so UNHELPFUL. This like watching someone put together an IKEA item with no clue what everything in the middle is?
@jackbauer26989 күн бұрын
It's just rust converter.
@moonolyth4 жыл бұрын
Pricy wool but no doubt very efficient. Been planing one of these for much time. Yours is very simple yet very well built. I am wondering how the inside shell is holding up. I may just go the wool method. I was going to use dens 2300 cement for the shell and mix that cement together with bean bag filler (Foam), vermiculite, and other to cut cost in place of the wool, but now I'm rethinking. I have 80 bounds of scrap bronze to make small figures with. Thanks for the show and tell !!!
@BenFreemanDC2 жыл бұрын
How can he just put in wool insulation and then cement? Other guys used kiln bricks. It seems like the wool will catch fire or something pretty soon.
@moonolyth2 жыл бұрын
@BenFreemanDC it is fragile there is a slury to coat over. It won't catch fire.
@bigboybuilder2 жыл бұрын
good job, I found that the dense lining soaks up a huge amount of heat which wouldn't be a problem if ran for an extended period of time. i removed the hard brick and replaced them with soft brick 26's the temp in the furnace went past 2424F (that is max for a K tc) as soon as i sparked it off. it lives outside and is a little over 20 years old. Another thing you may want to keep in mind when building a furnace is the lining will expand and if the shell will not allow this it will crush it's self.