October 17, 2025Oct 17 I'm looking to make a new propane forge, and while I saw brick pile style forge, I would like some advice for the construction and materials. I saw in another thread the Morgan Thermal Ceramics K26 firebricks, and I was wondering if there is a specific size that I should use, as well as the ideal measurements for the forge. I plan on using two Frosty T burners, as I already have them. I live in the US, so I should have access to the same suppliers as most of you do. Any help would be appreciated, I'm currently at a standstill trying to make a good forge for cheap enough I can afford it.
October 17, 2025Oct 17 If you put your general location in the header I wouldn't have to ask where you live. Morgan K-26 IFBs aren't sold in outlets everywhere in the USA. There are 2 places in the state of Alaska that carry them and only one more who will order them. Of course this may have changed since last I checked but I still have half a case in the shop and I'm pretty much retired. FYI, I have not checked prices, outlet locations, available sizes, etc. and I'm not going to do it for others. However I will say last time I did look the K-26 was one of the lower temperature rated light refractory shapes HWI made. IIRC a standard brick is 2.25" x 4.5" x 9", less the mortar gap. That one I can never remember but a simple web search will give you good numbers. There are also plenty of online "books" on basic brick masonry so you can design your own brick pile forge. Just remember do NOT mortar them together, even excellent IFB will break up without room to expand with the rapid thermal cycling between room temp off and 2,600f. My no weld brick pile forge is powered by a 1/2" T and comes to high yellow heat in about 3 minutes. If it were mortared together rather than loosely clamped it wouldn't have survived the first firing. Anyway, give us the general size, shape, etc. of the forge you wish to build and we'll be happy to help. We aren't going to look things up and such for you, that's your job. Okay? Frosty The Lucky.
October 17, 2025Oct 17 Hi there and welcome. You might want to put your location under your profile, not just in the post. Otherwise no one will remember you're from the States. Try a google search of: "properly tuned t burner will bring to welding heat" site:iforgeiron.com You'll get a google search of a list of I forge Iron threads about T burners and forge volumes. I had a quick look through a few of them to refresh my memory and found that 1 x properly tuned 3/4" T burner will bring 300-350 cubic inches to welding temp and 1 x properly tuned 1" T burner will bring 600-700 cubic inches to welding heat. Cheers, Jono. Arrggh! I see Frosty types faster than me!
October 17, 2025Oct 17 Author I'm planning on building a medium size forge, not just for knives, but also wider workpieces. My primary concern is how to affix the bricks, as I could find no info on that searching this site. My burners are 3/4" A D-shape (or vault) would be preferable, as I understand it, but whatever you experienced folk think is best, as I've had no prior experience with propane forges.
October 17, 2025Oct 17 Most use angle iron, threaded rod and bolts. With some careful carving (IFB cuts and carves easily, like Hebel block) and a few extra bricks, you could create a D shaped forge. It would be easier than some other materials to mount the burner at a tangent across the top of the D by drilling perpendicular to the outside of the brick and through into the curve.
October 17, 2025Oct 17 Good Morning, Welcome to this World. I used a stack of Bricks for over 10 years. Make a framework to hold Bricks lying flat, this is your Floor. We used a 45Gal Drum on end as a Base, your Frame will be horizontal over the top of the Drum. Cut a hole in the side of the Drum about a Foot from the bottom, horizontal cut about 1/4 to 1/3 of diameter. Now make 2 vertical cuts with a radius (like a church window). Put water in the bottom (this acts like a counterweight) Put your Propane Tank in the water (this acts like a Heat Sink and slows down the freezing of the Propane Bottle). You can stack the other Fire Bricks to make any configuration of your Forge, you don't need any Mortar. We cut a couple Bricks and made a single Burner in from the side. You will have to make a stand to support your Burner. With this configuration, 2 bricks high, 1 Brick wide, we were getting a 36" long heat in 3/4" solid square bar. We made a 4 wheel Dolly for the Drum to sit on, this allowed us to move it when we were finished for the Day. The down side of a Brick Forge, it takes 10-15 minutes to pre-heat the Forge, before you can start work. The Positive side, on a cool Day, your Workshop becomes warm. The byproduct of burning Propane is Carbon Monoxide, YOU MUST HAVE LOTS OF VENTILATION OF FRESH AIR, or you can/will take the/Your Final Sleep!! Neil 14 minutes ago, Capitalist said: Alright, thanks Hefty. Any specific drill for the firebrick? We used an old Handsaw, for Wood
October 17, 2025Oct 17 If you use K-26 or the equivalent Morgan ceramics bricks you can drill holes or cut it with sharpened popsicle stick. A keyhole saw works nicely for interesting shapes. I use an old hole saw with a long pilot bit in my hand drill to make burner ports. An old dull carpenters cross cut saw works fine, rip saw tends to make chips but works fine. A shoe rasp is an excellent way to fine tune shapes. No special tools to cut, drill and shape Morgan K series IFBs, they're softer than chalk but retain full strength to their full rated temperature and are insensitive to caustic forge welding fluxes. Capitalist, "medium" size is subject to personal opinion. Cubic inches and shape are something we can work with. A D shaped forge is a good shape if you can make the vault reasonably smooth otherwise all the 90 degree positive and negative angles form hot spots and cooler flame shadows which makes re-radiated IR rather odd. A smooth curved roof on the other hand behaves like a lens focusing the radiated IR down the center of the forge. It wouldn't be so hard to make a smooth vaulted roof if you stand the IFBs on edge spanning the chamber. Then you can simply cut the curve you want and clamp it together. Remember the majority of the IR will radiate perpendicular to the refractory surface hence a dome or vault roof "focuses" re-radiated IR towards the center. Make sense? I strongly advise a good preferably zirconia containing kiln wash as a last layer of armor. Zirconium is impervious to caustics like molten borax and is just shy of diamond hard. Better still it's a very poor conductor, including thermal energy. This means the layer in flame contact in the forge doesn't conduct flame energy to the brick backing it very well so the zirconium acts like a thermal concentrator and will reach the actual flame temp. Note that conduction and radiation are two very different types of energy transfer meaning the zirconium in the kiln wash radiates energy it can not conduct into the brick liner and radiates it into the forge chamber where it does work for you. Hmmm? Frosty The Lucky.
October 17, 2025Oct 17 Author What I meant by medium is larger than just a knife forge but still efficient, as I am a bit cost conscientious. So somewhere around a 6" radius
October 17, 2025Oct 17 I’m not sure if I missed your intent here, but something seems off. V=Pi * r^2 h, I’m getting 1357in^3. That’s fairly large (2 - 1” burners). If you meant 6” diameter, that would be 339in^3 (1 - 3/4” burner). Keep it fun, David
October 17, 2025Oct 17 A 6" radius x 12" = 1,357.7 cu/in. and three 3/4" T burners. Assuming you meant 6" "Diameter" you'd get approx. 339.3 cu/in. for one 3/4" T burner A square chamber 6" x 6" x 12" = 432 cu/in. too large for one 3/4" T but you can turn two 3/4" T burners down and not turn it into a melter. This is barely math. At the risk of waxing pedantic . . . again. To learn a craft you have to learn the jargon. Jargon is a trade language with terms, meanings and context relating to that craft and probably nowhere else. For example a visitor to my shop is watching me sweat over the anvil and asks, "What are you doing?" I look up and say, "This is upsetting," so s/he responds, "What's upsetting?" I explain, "thickening the cross section by reducing the length." The experienced craftsman has to bear in mind the casual onlooker doesn't know enough to ask a good question or understand the answer and unless there are guild rules against telling "secrets" has to translate into vernacular. Unfortunately for the new comer to the smith's craft our jargon is a living thing and changes, the real wrench in the gears is the internet where people are misusing terms or just making them up, some deliberately to put their stamp on the craft. I'm not picking on you when I say you don't know enough yet to ask good questions or understand the answers. I blame a lot of this on the edu. system over the last few decades. Stick with us, we'll get you up to speed. I see we're typing at the same time David. Good morning. Frosty The Lucky.
October 17, 2025Oct 17 Author Well, as it is a semicircle, the calculation should be (pi(6^2))x12/2 at least that's my understanding of it, thanks for your patience dealing with noobs like me. So assuming a semicircle, the volume calculation should end up just below 700 cubic inches, sorry for not specifying that
October 17, 2025Oct 17 Author looking online, I'm seeing that the firebricks aren't too expensive, but the shipping on all the suppliers I've looked at so far doubled or over the price on shipping/handling. Any advice on where to get the bricks without paying exorbitant fees?
October 17, 2025Oct 17 Have you looked at the HWI retail outlet locator? Other places to call on the telephone are furnace repair and supply companies, ceramics suppliers, ask for kiln building supplies. Call them on the phone and ask politely. selecting the "contact" button on a web site only gets you ignored unless you're ordering large quantities or are a large company. Yes, for you and I regular guy we have to make good impressions on the receptionist who knows more about what's available, pricing, availability, shipping, etc. Than the guy at the front counter let alone the boss. Be nice, don't waste time talking about what you want to do with the materials. Asking about temp specs for brick, refractories, etc. is fine just don't get chatty. They're usually very busy people. It's a sad truth, shipping is a killer. You aught to live in Alaska if you want to get cozy with shipping doubling the price of everything. However, if you know someone living close to a supplier you might be able to talk them into shipping stuff to you postal flat rate. I haven't checked flat rate boxes but I believe you used to be able to get 3or 4 IFBs in one of the larger boxes and they're way under the weight limit. What all do you think you'll need to build a brick pile forge? I'm also curious how you're going to make a smooth vaulted interior from bricks. Frosty The Lucky.
October 17, 2025Oct 17 Author well, for the smooth interior, I was thinking of sanding/grinding the bricks for that, and about 20 bricks to err on the side of caution, as the math I did got me 14.86 bricks for the sides, and then extra for the doors. I don't exactly know how I'll affix them, probably with bolts and strips, and the innate integrity of a semicircle. Always open for advice/being told what I'm planning is a bad idea etc. I say with bolts and strips because somebody said not to use mortar on the forge due to expansion in the high temperatures. There is an outlet of the HWI pretty near, but I'll wait till tomorrow to call them.
October 18, 2025Oct 18 IFB cuts easily with a skill saw which allows you to set the angle of the blade. You want to avoid grinding bricks of any kind the airborne dust is a breathing hazard. So is using a skill saw but not nearly so bad. Wear a respirator, the dust can have long term effects on your lungs, think mesothelioma, badness. When you write, "someone said not to use mortar . . ." are you making a joke or do you NOT remember that is what I told you? Aren't you keeping a copy of these posts? You should this gets more complicated a written notebook with sketches is a good idea too. Even if you don't use a particular idea when you think of it, it might be THE perfect thing in the future. Frosty The Lucky.
October 18, 2025Oct 18 Author Sorry, I've been reading a ton of these recently and got it mixed up What kind of angle should I set the burners at? Is there also a golden ratio for how far from each other/the ends of the forge they should be? Should they be parallel to the base of the forge? Hefty suggested perpendicular to a brick, but that leaves a lot of leeway for error for me
October 18, 2025Oct 18 Stop reading a bunch of different peoples forge building advice, everybody does it so it works best for THEM. Pick ONE effective forge plan and follow it. You don't have the knowledge or experience to mix and match different ideas successfully. pick ONE. No, There is no magic, golden or otherwise for this stuff. The only real rule for burner orientation is do NOT aim them into a pocket, say corner or directly at the far wall in a cylindrical forge or the flame will form a high pressure zone which will inhibit a NA burner from operating well. Frosty The Lucky.
October 18, 2025Oct 18 Our local ceramic supplier sells fire bricks both soft and hard although I dont know the ratings. They also have kiln shelves and castable refractory. Good luck
October 22, 2025Oct 22 On 10/19/2025 at 12:08 AM, Capitalist said: Hefty suggested perpendicular to a brick, but that leaves a lot of leeway for error for me What I suggested was that you can drill it easily, perpendicular from the outside, but that a good placement in a vault forge is so that the burner entry is at a tangent to the interior vault surface to encourage swirl. Rough sketch below:
October 23, 2025Oct 23 Author I see what you mean, that seems good. I did finally manage to find some cheap bricks that I'm picking up Monday, so we'll see then.
October 23, 2025Oct 23 Good Morning, If you hold 2 bricks together and then drill your hole with the center at the seam, you haven't lost the strength of the brick. Been here, Done this. Neil
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