Newbie building first forge... burner advice?

[LiveWire]

Hey guys new member here, first post.  Just starting out in the trade and instead of buying a forge im one of those guys that likes to do things myself.  Ive seen lots of articles and have been hovering on this forum for a while now and am pretty sure ive got it down but just looking for some advice before i finish the whole thing up.  

I have a small old steel 10lb propane tank that ill be using for my beginner forge.  I have lined it with 2" of ceramic wool and am about to rigidize and htc the inside but before i did i figured id reach out for any advice.  This will leave my inside dimensions about 4" tall by 8" deep.  Im thinking this will be a good small efficient forge to begin the hobby with.  My problem is with the burner size, ive seen some cubic inch to burner ratios but being such a small forge i dont want to over do it and melt my lining?  What would you guys reccomend as a burner and any other advice would greatly be appreciated. 

Thanks!

-Conor

[Mikey98118]

Overdoing the burner size, will not melt you lining; it will be much more inclined to turn your forge into a flame thrower. However, naturally aspirated burners tend to have very long turn-down ranges. To make a long story short, a 1//2" "T" burner will do fine in that forge, so don't get sucked into looKing through the Burners 101 thread. Go straight to the  T" burner thread, so you can spend the added reading time in the Forges 101 thread, which you badly need to read RIGHT NOW.

That is a great beginning on an excellent forge, so please learn what else you need to know, before it ends badly. For instance, that hard half brick needs to be replaced by a Thermal Ceramics K26 brick (eBay), before the insulation is rigidized, and the whole interior gets a hard heat reflective coating.

[LiveWire]

This is why I asked.  Thank you for the quick response Mikey!   So correct me if im wrong, after re-reading the forges 101 would you recommenced not using the ITC-100 after rigidizing and instead use a zirconium silicate/veegum mixture for the outer surface and as you stated the Thermal ceramic brick in place of the cheap firebrick?  Also on your recommendation im planning on installing a 1/2 "T" burner at about 2-3" from TDC (roughly 2 oclock) with 2 sets of set screws?

[Mikey98118]

1 hour ago, LiveWire said:

This is why I asked.  Thank you for the quick response Mikey!   So correct me if im wrong, after re-reading the forges 101 would you recommenced not using the ITC-100 after rigidizing and instead use a zirconium silicate/veegum mixture for the outer surface and as you stated the Thermal ceramic brick in place of the cheap firebrick?  Also on your recommendation im planning on installing a 1/2 "T" burner at about 2-3" from TDC (roughly 2 oclock) with 2 sets of set screws?

Back in 2004, I barely decided to recommend use of ITC-100 as a heat reflecting final coating, and even then I recommended separating the colloidal part of its contents from the crude particles in its formula, by adding more water to a little at a time, in a clear water glass. Without that separation, it is in my estimation, little better at heat reflection than Plistex, etc., and mechanically far less tough. Today, this product costs about four times what it cost back then; and works no better.

I did not speak out against ITC-100 for all this time for the same reason I gave it a qualified recommendation in the beginning; there was no better performing substitute at a reasonable price; this is no longer true.

Zirconium silicate's crystaline structure is about two-thirds zirconium, bound with about one third silicon in an industrial process that only produces colloidal grade particles. It is mechanically tough, use rated for 4550 F, highly heat reflecting, and insulating. It is supposedly flux resistive.

Zircopax is CHEAP in comparison to ITC-100. When I ran across the Digitalfire article on how to use Vegum T (best) or benonite clay (acceptible) as the perfect binder for zirconium silicate (to make everything from thermal armor to thin heat reflective coatings) ITC-100's days became numbered.

Plistex and other such coatings will go right on being used, because they are effective, economical, and easily used, but the bully on the block has just met the new kid in town, and he's going down!!!

The Themal ceramic K26 brick has roughly equal insulating abilities with ceramic wool at 2000 F. Unlike old style insulating fire brick it will withstand rapid thermal cylcing, and is mechanically tough enough, that a thin coating of a castable refractory, or the zirconium silicate mixture above, will bring it up to snuff for flame impingement in a forge. On top of this, a single brick with shipping is about $11 from eBay. I would call this a typical "to good to be true" deal, if Morgan hadn't taken half a century to perfect it.

[Mikey98118]

As to your present half brick, it will do fine as part of an external baffle wall in front of you forge opening.

[LiveWire]

Sounds good.  I am all about doing it right the first time but im having one problem... while all this is great knowledge on what I should use as the best setup where do you purchase the zircopax and the veegum T and how would I mix it? I feel like this is all way over my head... I want to start hitting things with a hammer but in the process I am finding that now I am trying to understand crystaline structure, binding agents, colloidial grade particles etc.  I quickly looked at digital fires page and its tells me the same thing you said but im not finding a tutorial or guide on how to source/make this stuff.  

I dont mean to be a PITA but being this is the first time I have tried anything like this and I feel a bit lost.  I do like knowing the science behind it as this definitely helps me understand what im doing but I guess I still need a bit of guidance on the best way/how to do it?  Are there any threads of someone using this process yet?

[Mikey98118]

11 minutes ago, LiveWire said:

where do you purchase the zircopax and the veegum T

Both of these materials are important pottery ingredients. If you can't find them through a local potter's supply store, go on line and get them from Seattle Pottery Supply. I have not found another source anywhere near as good as them.

There are already a couple of guys on here who are experimenting with zirconium silicate and bentonite clay.

As to the science behind it: The Digital articles explain the why of how well these simple formulas work. All that is left is the science of re-emissive  coating materials. There are several metals, and their oxides, which are outstanding light radiation emitters, when heated. Zirconium is close to the best (cerium is number one). But zirconium, is also a preeminent insulator at incandescent temperatures.  Thin Zirconium coatings (up to .020" can be used as protective coatings on crucibles, without interfering with heat transfer through the wall). Coatings as thin as .040" are used as insulating layers. Every additional bit of thickness increases the insulating value of a zirconium coating, or refractory.

BUT zirconium changes its crystaline structure from cubic to hexagonal before it ever reaches forge heats; it then changes back to cubic structure on the way back to room temperature. So, zirconium tends to pulverize any hard refractory that it is included in; very small amounts of very fine particles can actually improve refractory toughness, by creating micro-cracks, but that is not Germain to this discussion. Zirconia mixtures (zirconium oxide) Can have its crystalline structure stabilized, but that used to be very expensive; it isn't anymore, but during the decades it was, zirconium silicate became a popular reasonably priced substitute; this is because the manufacturing process produces particles so fine that they won't create cracks in a refractory formula, making an end-run around to whole problem.

A few forward thinking guys on IFI have been combining zirconium silicate, with various binders, to make a superior "kiln wash" for years, but now that we have really effective binders available, they will go far beyond that.

[Frosty]

Welcome Livewire, glad to have you. A sparky I take it eh?

There is at least one more fellow who has joined in on this run of experiments. Maarten in the Netherlands has been experimenting with Bentone, a grade and brand of bentonite clay and getting good results with 4% Bentone to 96% Zircopax. His results seem to be promising and I have a lot more experience with bentonite as drilling mud so I have some ideas for mixing but haven't done any experiments myself.

Veegum seems to get messy hard to work with in concentrations much higher than 0.5% and the site recommends between 0.2%-0.4% I'm waiting to see what Mike discovers before I start messing with it. If I can find someone who'll cut loose with a couple lbs. of ceramic grade bentonite I'll start tinkering with mixing techniques.

The problem with having any kind of a how to for folks to use is we don't know how to make the stuff work ourselves and are still tinkering around. 

However with my experience using bentonite drill mud I have ideas for approach the other guys haven't thought of yet and didn't think were practical till Maarten posted about the ratio he's had such good results with. There is only one realistic way to use bentonite or Veegum. (a clay group closely related to but different from Bentonite)  Either group of clays are so fine, Bentonite is typically 2microns x 3 mics, x 0.5 mics. Flat platy rectangular crystals and Veegum is much finer. This is in the range of just a little bigger than water molecules so it takes a LONG time for water to mix even under force. Maarten was mixing the Bentone and zircopax dry then adding water and mixing long and hard to get to formable consistency.

Veegum needs to be mixed with the water and allowed to go into suspension before mixing with other materials. I think this is a good approach for Bentonites as well. Figuring how to get the desired % will be the trick.

Anyway, that's why there isn't any kind of useful how to yet. We're shamelessly hoping someone comes up with one we can use. 

Frosty The Lucky.

[Mikey98118]

Zirconium's cubic crystalline phase is smaller than its hexagonal phase.

[LiveWire]

Thanks Frosty, Yes... Master Electrician here.  Maybe one day add Master smith to my list of accomplishments.  Being new to the forum(about a week) I havent had time to read every post... yet.  haha.  So i wasnt sure if anyone else has attempted this process yet.  I saw Maartens write up in one of the posts about the clay but figured he was just using what was available to him as an alternate to what we could get here.  

Mikey I think I will try seattle pottery supply.  So in laymans terms it sounds like were basically "Glazing or Kiln washing" the rigidized kaowool?  Mixing a small batch of VeergumT then adding it to a bucket zircomax or maybe adding the veergum to the zircomax then adding water.  Should this be a trowel-able paste or more like a pourable self leveling texture that will "Glaze" the inside of the forge?  Im not sure.  Plus its a guessing game as to how much to buy of each medium? I am very interested in this process because it seems like the most effective final lining and thinnest thus keeping my forge area maximized for only a small blade forge from a 10lb propane tank.  Unfortunately I am severely lacking in the knowledge on how to do this, I have no experience with this sort of thing.  Mixtures and ratios are not my thing.  Bending and moving metals I can do, I know enough about the chemistry and makeup certain metals and such for welding and forging by hands on experience and what ive been told, what ive tried and havent tried but this sort of chemistry and molecular binding agents and stuff I am a bit leery of.  I dont want to waste too much money with trial and error on what was supposed to be my first crack at building a cheap effective and durable first forge.

I firmly believe in do it once, do it right so Im willing to take your advice and give this a try.  Sounds like you guys have really done your research and know your stuff.  Like I said this is my first forge build.  Got the tank for free so thats how I chose it.  No other reason besides I wanted a small efficient forge.  Read too many stories of guys building ridiculous huge forges wasting energy and fuel.  I want something thats gonna be efficient and long lasting.   Im hoping this being my first ever forge to be able to one day show my kids, "This was dads first forge and I still use it today" - 10+ years from now.  

[Frosty]

I see you've arrived at the heart of the zircopax + bentonite or Veegum flame face current cutting edge. For us anyway. We're still winkling this stuff out. Mix it thin like heavy latex paint and it's kiln wash. Mix it thick like modeling clay and it's a hard refractory inner liner + flame face. My issue with thick is shrink checking as it dries, too much moisture and it begins displacing clay so when the moisture drys out the clay will shrink. visualize dry mud in a puddle.

However, you ARE making a mistake common to anyone breaking into a new craft. You are trying to design a "perfect" tool and you don't know what you're going to need or want in just a short time. For now think of the first forge as a wear item, it is regardless but the first one wears fast. Even if it's just wearing on the nerves. Everybody does it, all the "old guys" here have forges collecting dust under a bench or out in the yard collecting leaves, I have several. I may be dragging out my large coal forge though one of our guys has located one of the seams of good smithing coal.

Anyway, keep it simple. Have a cat, know someone who does? Cheap clay kitty litter is bentonite. Put some in a jar, put in about 2-3x that much water close the lid and let it dissolve. That's your kiln wash, if it's too watery let it evaporate, adding more litter takes longer and is more by guess and by gosh but works. When it's thick latex paint consistency butter the RIGIDIZED kaowool and just paint it on. When it's dry, bisque fire it with a bernzomatic torch, let it cool and fire up the forge burner for a FEW minutes, let it cool then fire it to red heat and let it cool again. She's ready to rock.

If you want to use it like plaster use less water, peanut butter consistency is pretty darned wet but okay. It's going to take MORE time to dry, an incandescent light bulb and a fan will help a LOT. Be patient it will be rewarded. Fire same as above but skip the bernzomatic torch. A small forge should spend some time in the kitchen oven, 170f. for a few hours then 230f. for a few hours to drive off the hygroscopic moisture. Bentonites should get the 230f. over night at least that was the standard time for a moisture content test in the lab, about 3"00 pm. to 8:00 am the next morning.

Don't worry about the whole zircopax IR re-radiating hot face / kiln wash thing till we get something worked out that isn't an exercise in "WOW what  happened?  Patience will be rewarded and you get to beat HOT steel in the mean time. Hmmmm?

Frosty The Lucky.

[Mikey98118]

16 hours ago, LiveWire said:

Mikey I think I will try seattle pottery supply.  So in laymans terms it sounds like were basically "Glazing or Kiln washing" the rigidized kaowool?

On  rigidized Kaowool, and on K26 brick you would be applying a thin coat, which penetrates, and interweaves with the underlying material; this is important, because different ceramics have different coefficients of expansion. If you mix up the refractory for use as a superior tile, it would most likely need to lay on the outside of blanket or brick--not bond with it--we don't yet know whether or not it would crack away from the insulating layer, if used that way; it's "early days" yet.

We also don't know that such a de-lamination would be a serous flaw, or merely irritating to my fellow perfectionists. We do know that the ability of both ceramic wool and K26 brick to breath is going to be a big help in proper drying

[Mikey98118]

Frosty,

I think your last post needs to end up on Forges 101 as a highly valuable alternate method. Choices; I like as many of them as we can get.

[MonkeyForge]

Agreed on Frosty's last post. will be useful in forges 101. I wanted to chime in but have not had time to experiment further. Shrinkage has been on my mind as well. Eye-balling the test tile wet and air dried there seems some shrinkage not much. same for size after firing. Then again, I did not measure so I owe you an answer to that. 

[Frosty]

Okay, on it's way.

Frosty The Lucky.

[Mikey98118]

19 minutes ago, MonkeyForge said:

Agreed on Frosty's last post. will be useful in forges 101. I wanted to chime in but have not had time to experiment further. Shrinkage has been on my mind as well. Eye-balling the test tile wet and air dried there seems some shrinkage not much. same for size after firing. Then again, I did not measure so I owe you an answer to that. 

Using the refractory as a thin coat is a no-brainer. But using it as shaped refractory parts, and as thermally armored tile is going to be much more important; keep up the good work.

[Frosty]

It's cut and pasted in Forges 101, good call on the suggestion.

Maarten: Being able to fire formed refractory pieces is down right exciting. It has me thinking about recuperative wall forges again. It's been shown repeatedly in recent work that it's just too easy to build a recuperative burner and over heat it to the point of pre-ignition. The Sandia forge is a good example.

In commercial furnaces however the exhaust gasses from the chamber are often circulated between the flame contact layer and another contact layer and the backing layer. I gave it a lot of thought after my first pipe forge but the paycheck job and the time and effort to experiment . . . well you get the idea.

If we can make a zircopax + bentonite refractory Tile work as a stand alone then the recuperative forge wall reappears on the radar. Well, MY radar anyway, it's probably just too much work for the return, we're not talking commercial sized furnaces. 

Frosty The Lucky.

[Mikey98118]

Yup; and a zirconia rich refractory is the perfect choice for the job.

You can not only use it for the double refractory walls, but for the fan too.

While we're add it, this formula would be perfect for ceramic chips, in a chip forge. Best of all, it can stand the higher temperatures needed to keep the lower parts of such a forge from sagging out of shape.

[Frosty]

Fan? Most recuperative wall furnace drawings I looked at relied on flame circulation and final exhaust ports to circulate the flame between thewalls.

I hadn't thought of a chip forge! Oh yes. I wonder how a NARB would work in a chip bed forge. Ooooooh!

Frosty The Lucky.

[LiveWire]

Curious as to how fragile is this stuff going to be as well.  Especially with a thin coat.  Much like a glaze I wonder how well itll hold up to pulling pieces in and out banging the edges or material dropping out of tongs etc.  In theory it should be pretty hard but as we know sometimes the harder things are the easier they crack and chip.

[Frosty]

We'll let you know. As a general rule a brittle material is as strong as the underlayment. For example lay a piece of window glass on a clean table top and you can walk around on it is high heals. Lay it on a piece of foam rubber and almost any pressure will break it. 

Looking at the pottery and ceramic sites it looks like bentonite additives actually make ceramics stronger by lowering the vitrification temperature while raising the melting temp. Of course I could have that bit wrong I didn't spend a lot of time studying things. I got me a working handle then off mental voyaging the voices and I went.

Here's something to think about though. Know those ceramic knives, frying pans, etc. that are popping up everywhere? The knives are WICKED sharp and stay sharp. Sintered zirconium silicate they are. No, don't even think about it, the vitrifying temperature for zirconium silicate is a couple thousand degrees hotter than your forge is likely to EVER get. 

Frosty The Lucky.

[SLAG]

Thanks Jer,

I just looked the chemical up. Impressive.

Melting point 4620 F. Yah the forge will never make that temperature.

SLAG.

[LiveWire]

Tested my 1/2"  frosty t today.  I would say this seemed successful.  Only ran it for 10min today for the test because I still haven't rigidized the wool and coated it yet.  Waiting on supplies to arrive.  

[Frosty]

Looks good from here.

Frosty The Lucky.

[Mikey98118]

Yes; he did a good job.