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) 

12 hours ago, JHCC said:

In masonry, "cement" without further qualification usually refers to portland cement, a mixture of lime, clay, and gypsum. Mixed with water and sand, it can be used as mortar; with larger aggregate (such as crushed stone), it forms concrete.........

Make sense?

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). 

2 hours ago, Frosty said:

How the pros at Bernzomatic, etc, get their burners to perform is well above my level of competence. 

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.  

1 hour ago, Frosty said:

I've been thinking about induction forges a long time, I just can't afford one. <sigh>

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. 

49 minutes ago, Frosty said:

Sure. I'd buy a hand torch. Making them much smaller than 1/2" passes the point of diminishing returns. I can't make a 3/8" that works as well as a Bernzomatic and if I use Mapp then there's no competition.

 Frosty The Lucky.

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. 

I agree.  By bigger I was thinking more common size using 20# propane tank or similar.  I think I'd go with the D shape, and burners from the side, though I know myself and likely a ribbon burner like yours is in my future, haha.  

That's a long way off though, likely after my next move. More immediate project is a smaller propane hand torch for spot heating things.  Need to start doing some research on that.  Any recommendations on a starting point? Thinking a 3/8" version of one of the common designs. 

16 hours ago, Frosty said:

That looks about right, I believe the dark color is iron oxide dissolved in the flux. 

Just dripping molten borax on regular fire brick doesn't do much but stick but it will erode in a forge

 

Thanks.  That spot is actually in the forge directly under the main flame.  I've put at least another 10 hours of burn time in it, mostly in 2-3 hour chunks, and the flux spot hasn't changed or deepened. At this point the flux is likely well mixed with oxides and little bits of scale etc that have found there way in a some point. 

I'm quite happy with this little forge still.  It's taught me a lot and is working beautifully with your 1/2" T design.  The length is no problem but if /when I build it's replacement I see I'll want something a bit wider for the kind of things I like and want to do. I'm finding I really enjoy the decorative scroll/artistic side result as much as knives. 

Thanks for all your help. 

I tried some 20 mule team borax as flux yesterday.  I intentionally let about 1.5 teaspoons of the borax go into the brick. I had the forge at welding temps (and did my first two successful forge welds ever in the process, using sucker rod drawn down to about 1/8" flats and well cleaned... But I digress ) for about an hour.  Today I had it up to temp for about 2 more hours while I made some tongs. 

This photo is after all that time.  The flux worked down into the brick a touch. I can feel a depression with my finger, maybe 1/32" deep. That area already had minor surface damage and some cracking, hence I used it to experiment.  I have no base on what is normal but if that's all it does I'm not worried for now.  This area is right under the flame.  It doesn't seem to be increasing in size or depth with time.  Scrapped some molten flux at welding temp onto some scrap brick outside the forge and it didn't eat in at all.  It does bond very strongly to the brick. 

Thoughts? 

4 hours ago, Frosty said:

We're always interested in new refractories. Someone here was talking about buying zirconia IFBs, expensive but pretty bullet proof.

My apologies.  It took me a bit of searching to find the right page of info, was just trying to make it easier for people who might try to help me.  I get the spam issue though.  I'll add that to my list of rules I didn't find. Saw one saying not to link to sales pages..... 

But I'll stop burying my actual question again. 

Frosty, have I read correctly that your use the k26 bricks with flux and they hold up?  Am I right in guessing it's the higher alumina and lower silica that allows this, if correct?  If that is all true and I've read you correctly, then the bricks I have should work fine too. 

Thanks

Sorry for apparently posting a commercial link.  I didn't see it as anything being for sale, it was a direct link to their specification page only.  No way to buy it that way.  I figured if I was asking people for their opinion on a brick it was only polite to not make them hunt around the internet looking for the pertinent data. 

My apologies if that was inappropriate. 

1 hour ago, Irondragon Forge & Clay said:

Thanks deepwater, it's not really my job..... 

My apologies.  My phone seems to show a pretty simple version of the site and there are no indications like member v moderator, post counts, etc that I see on other forums.  No biggie, I just assumed you were an official mod.... Guessing you're more volunteer but I appreciate the effort you put in here. 

Nathan, if you read around here for a bit you'll find that one of irondragon's jobs on the forum is to welcome new members this way.  They are not trying to annoy you, they are trying lay the groundwork for getting new members to integrate as well as possible. 

I'd suggest start with reading Frosty's ribbon burner thread and then ask questions based on what you learn there. 

I've found a nice supply of BZN's 3000f insulated fire brick.  I've been using them for my small brick pile forge and they seem to be holding up well.  I'd like to try some forge welding and wondering how they will hold up? 

I've read a few people here, Frosty especially, mention using the Thermal Ceramics K26 bricks and that they are less susceptible to borax flux damage. Reading around here it seems that higher Alumina and lower Silica percentages are what matter.  I've included a link to the BZN page describing their IFB specifications. Commercial link removed  Thermal ceramics data is available in and easy to find pdf, but not sure if I can post it here. 

Short version, k26 percents are 48% alumina, 36% silica.  BZN 3000F are 70% alumina, 28% silica. I've looked up castolite 30, but it is a vastly different makeup and while all the words are familiar, I'm not qualified to compare anything.  

So, thoughts on how the BZN would holdup to borax flux?  I could just try, but I don't want to waste time, money or bricks if it's a guaranteed failure. 

Thanks all! 

2 hours ago, Glenn said:

Some of your images are in png format.  For this forum jpg is better.

I'll try to crop closer in the future.  But, I promise no image I have uploaded or linked has been in png format.  That is not a format I have ever, or current used. I've checked the images on my end that I've uploaded and none were in png when I uploaded them.  As with the file size, I think the forum software is doing something hanky during upload 

3 hours ago, Glenn said:

.....When you post the images into the gallery it posts the same image into the forum to alert folks there is new material in the gallery.  Multiple images results in multiple posts and can tie up the bandwidth of those trying to view just the forum.   

So we shouldn't use the gallery?  That's fine and sorry if I misunderstood its purpose and functions with this site's software.  Or am I misunderstanding you still?  I suspect I am. If I just upload an image to my member gallery how would the site know what forum to put it in?

Again, I suspect there is something weird software-wise happening here also.  You said some of my images were approaching 3megs but I've triple checked my files, I've done a lot of photo editing in my time and have a software and naming protocol very specific to me. I know for a fact the largest image I uploaded was <350k and most were <150k with a few <70k

Would it be ok we pull this into a new tread in support subforum (or wherever you prefer) or move it to pm?  I like the conversation but i feel my original posts and questions were already being befuddled by other stuff not relate to me and now this is just going to bury my actual questions and comments.  I'd be happy to continue this discussion and try to figure it out.  Researching seems to show that image usage here is confusing to many people.  I'm struggling and I have moderated forums such as this in past.

Is it OK that I use BBCode to place images hosted at my own site inline with my text?  Some places prefer that, for many it is a big no no. I have tried to find this info but the only thing I have found regarding images or the gallery is very outdated with the most recent post being from 2017.

Thanks!