deepwater

Thank you all for the input! I believe BZN is it's own company. I tried posting a link to the specific bricks datasheet and was chastised so I'm not sure what more I can say. Box is labeled BZN Materials, Littleton, Colorado. They've been holding up quite well, I'm my limited experience. I'm not gentle with things, I've reshaped my forge several times. The bricks I bought were tapered 4" on one end to 4.5" other. They were new old stock from a local plant that closed but the company BZN still has an active website. Each has cracked across the middle from thermal cycling but my frame holds it together without issue. I've intentionally gone heavy with the borax and let it get on the brick. When I rebuilt it the other day (to make it bigger) I pulled apart the brick that was directly under the flame and that had probably 1/4 cup of borax melted onto it over about a dozen sessions. The flux had eaten into the brick about 1/8" at most. Seems durable enough for me!

With a 12" long forge, if you frequently do blades that are about the same length you may want to consider 2 smaller burners or a ribbon burner to get a more even heat. One issue is that 1/2 T burners are about the smallest that can be practically made due to availability of small orfice mig tips. I've seen a few people get around that by using the nozzles from 3D printers, which are smaller and have a lot more orfice options available. With this you could do 2 3/8 or 1/4 burners, though it's well outside my knowledge base to suggest any more. Others, like DrFrankenburner and his 3d printed and cast burner parts, have gotten very good results from rather small burners and his thread is a great read

In my limited experience, one advantage to having some extra room is that you can heat you materiel indirectly, thus keeping the harsher propane flame of your delicate work and have more even heating of your piece. Forge shape and burner location/where it points can solve a lot of that issue. Also, a forge that is very close to the same length as your blades will require constant attention and manipulation front to back to get even heating from tip to tang. Though, with the tip containing less material than the belly of the blade, some attention and manipulation will always be necessary in a flame based forge (as compared to kiln or oven where the heating is less direct)

Clear as mud, err, cement, actually! Seriously, thank you. That was well described and helpful to me and I'm sure future readers will find that useful as well! Honestly, I was familiar with all that from the construction trades but I was wondering if the "rules" and nomenclature really transfered over to our purposes. I have been looking for a suitable mortar for my needs (described in my original post) in a small enough quantity to not be overly costly to buy locally or ship. Seems like all the typical brands I am finding are only 2000-2300f rated and they seem to be using the terms cement, mortar and refactory somewhat interchangeably. Follow-up questions: if the mortar I use will not be exposed to direct flame but will be approx 1.5-2" behind a 3000f soft IFB, do I still need a higher temp mix or might the 2k rated stuff work? My 2.5 thick bricks certainly don't get that hot on the outside. Too hot to touch, yes, but not 2 thousand degrees! If the normally available retail stuff is not suitable (brands like Rutland or meeco for example, the usual kinds found in better hardware stores ) can Kastolite 30 or missuo be mixed at a suitable viscosity to work as an overhead mortar once cured? Final question for now, how wet should I get my bricks when buttering them? Wipe with a wet rag, soak the bricks in a bucket, or?

Thanks Mikey! Is there a difference between morter and cement? I know the difference in construction but with this stuff the terminology used on those products seems somewhat arbitrary. And yes, I'll remember to butter the surfaces but thanks for the reminder!

I have a brick pile forge using BZN 3000 high alumina soft bricks. I'd like to fill in top two corners with 45 degree pieces to reduce the interior a bit and to aid in improving heat/flame circulation. Is there anything that I can use to morter the fillet pieces in ( about 2" wide on the square sides)? Will anything support the hanging weight at welding temps? I don't really want to spring for Kastolite or similar and am hoping I can use the dreaded, commonly available refactory cement (red devil, etc).

I might as well just give up then if it's above you, hahaha! But seriously thanks for the air VS oxygen reminder.

Thanks Thomas and Frosty! So, how to little plumbers torches and bigger O2/fuel systems get that sharp pencil like flame? On systems using oxy is it a byproduct of the higher pressure oxygen? Small naturally aspirated benzomatic style hand torches still achieve this concentrated tip though. That's really what I want, for use outside the forge as a bigger hand torch. I know the easy and likely best solution is an O/A or O/P rig but those are not feasible for me at this time. I have propane and a forge, seems to me I should be able to come up with a solution to make a larger naturally aspirated hand torch that will spot heat a couple inch length of 1/4" or 3/8" round or square stock to to bend at my vice, or to tweek already shaped pieces that will no longer fit in my forge, like the 12" dinner triangle I was making yesterday. Is it as simple as scaling up the tip /flare design of a smaller benzomatic style torch or does that idea go out the window as you get bigger?

Frosty, as always that's a nice bit of useful info. Thank you! I hadn't considered that the Fisher and Benzomatic type burners were dealing with different velocity gas. Makes sense with the Fisher /bunsen style (thinking back to my chemistry lab days) but I thought the smaller propane torches were basically operating at tank pressure, at least when wide open. I thought the smaller flames were a byproduct of a smaller orifice plus associated burner tubes and air holes. OK, let's say I want to experiment with a tapered cone (smaller at tip than at burner tube) or a flattened flare on a 1/2"T. Seems I'd still want an initial step bigger from the tube, then a chamber of sorts to give the fuel/air mix a place to slow its velocity and ignite, then my cone or flattened flare. Is that right? If so how big should that chamber be? I feel like a straight sleeve of a "flaree" seems to like about 1" of length on these to give what I think is the best flame. Will a shaped flare to concentrate the flame rewrite a similar sized chamber?

Oxy/propane or oxy/acetylene are the obvious best choices. I miss my old o/a as much as I miss my welder, lathe, and whole shop. What I was hoping for was something good enough to heat small areas of reasonably sized stock for scrolling, adjusting and cooking on wax/BLO. A portable 1/2 was easy to make with parts I mostly had on hand and is close to what I want. Actually, it works fine I just want to push its capabilites a little further. It certainly puts out enough heat to do what I want, but the bushy flame is a bit spread out and wasteful of time and resources. I feel like if I could shape the flame better, more like a plumbers' torch or brazing tip, sharper and more pencil like, that this would work great for my needs? Stainless steel sink drainer screen fit in the end of the burner tube? Plate with several large holes? I feel like bunsen burners and plumber torches often have those, maybe that's the answer? I don't happen to have any of that laying around but if it could work I'm happy to grab it and experiment.

I have no experience with induction anything though I have a basic understanding of the principal. Small ones, say up to a few inches across and capable of heating an inch or so of thickeness a few inches long arm to be coming onto the cheap ebay /Chinese market. Last time I cans across them the price was scary cheap. I wouldn't trust the scary cheap stuff but that tells me the technology might be sound enough to build your own for a reasonable cost, providing you have some electronics experience experience. I'm sure I've seen a few people in the 'net use old microwave transformers as a base. Again, no experience and everything has been done both good and cheap on the net if you look around enough. Near as I can tell most of those cool inventions are kept b right next to that pot of gold I misplaced at the end if the rainbow. Still, having your own induction unit may not be as our if reach as you think. As for my small burner problem, I simply threw together another 1/2" T. A bell reduce in had laying around is doing eh, ok, as a flare. I can heat small areas on but I know I'm not being very efficient. If I could find a way to shape the flame a bit better I think I'd be satisfied. Sadly, I have nothing laying around to make a sleeve for a flare, though an insanely quick test with some aluminum showed a much better and more concentrated flame. If I only had a piece of 3/4 pipe laying around I'd be golden Any tips to further shape and concentrate the flame aside from just a straight sleeve /thread protector/coupler?

Forgelet! You have put some thought into it! I honestly like the induction idea but without an unreasonably large size it seems only useful with specific needs and sizes. The idea of using a smaller burner and a way of isolating the heat in a forge kind of way is very cool.

At that point I feel like induction is the way to go. Though I really like your idea. Mikey recently suggested to me the printer nozzles from 3D printers. Off to do some reading.. Thanks buddy!

I understand that. I'm trying to find an economical way to spot heat steel up to 1/4 or 3/8 for bends and light scroll work, as well as random house/shop/farm jobs. In a perfect world I'd get an oxy/act setup but this isn't a perfect world, sadly. I might take the time and try a Mikey build or if I've got the right fittings around maybe experiment with your style. Even if it fails I enjoy the learning process. I don't need longterm efficiency, juts quick brute force heat.

That's too bad. The benzomatics I have won't get hot enough to heat up much and the bigger ones get expensive fast. I was hoping I could get $15 in parts to work by stealing the regulator and hose from the forge when I need it. This isn't something I need often. Oh well, back to the drawing board.