Forges 101

[Frosty]

To put it in different terms. Our tools speak to us all the time WE have to learn their language and pay attention. This is one, maybe the main reason I harp on trouble shooting by changing ONLY ONE THING AT A TIME. When you start changing more than one the tool's language becomes a random babel even the most experienced can't understand.

With forges and burners there are often several perfectly legitimate solutions of anything but even if you apply two correct solutions exactly, even the mythical PERFECTLY right the chances the results will be good are exponentially less likely.  Your forge and burner only looks simple, there is a lot going on, it's all interdependent and iterative. 

Frosty The Lucky.

[Mikey98118]

Yup; just so.

 

Also, the closer you get to right, the smaller every change should become; its easy to lly right past the target.

[Mikey98118]

High Heat Refractory formula

Zirconium silicate 97%, added to Veegum T 3%, forms a dense mold-able low shrinkage refractory. The Veegum will lower its rated temperature somewhat below zirconium silicate’s 4550 F rating; it has low thermal expansion ( giving terrific thermal shock resistance); it should be excellent for use as thermal tiles, crucibles, burner blocks, and for lining flame nozzles.

    Zircopax Plus, Superpax, Zircosil, and Excelopax, are brands of zirconium silicate flour (AKA zircon; ZrSio4). Veegum (AKA Veegum T,VGT). Veegum Pro is treated with an amine to allow it to disperse in liquids: In refractory formulas they serve as binders and plasticizers. Veegum is refined from the mineral smectite, in the form of  colloidal magnesium aluminum silicate powder, which becomes adhesive. Veegum swells into a gel, rather than dissolving into the water; thus it becomes a nonmigrating form of binding agent. It is best to mix this powder in boiling water before adding other ingredients. Veegum pro will disperse into water, and can be mixed cooled; it allows less water to be used, reducing shrinkage. When 3 to 4% Veegum is combined with calcined materials like alumina and zirconia (as grog) he resulting refractory can be formed like clay. Above 4%. the refractory will become sticky, and also require too much water (leading to cracks as it dries out).

[Frosty]

This is a new one on me Mike, made me do some reading. Veegum's a close mineralogical relative of bentonite eh? I didn't get a chance to look for sources, how available is it? If this stuff works better than kaolin and or can be mixed as a stand alone refractory liner I think we have a. . . 

WINNER WINNER CHICKEN DINNER!

Okay, that may be jumping the gun but I don't get to write that very often. 

Bentonite is what's typically used to plug the tap in cupola melters, scoop a very wet wad on the plunger and jam it in the tap against still flowing molten iron and it sticks and plugs without leaking. 

It's commonly used to patch surface damage to gas forge floors in some cases as a flux shield in gassers. 

This has me thinking all sorts of tinkerer things from hard refractory kiln washes, straight as a rigidizer to who knows what.

Cool Beans Mike, thanks for the brain fodder.

Frosty The Lucky.

[Mikey98118]

12 hours ago, Frosty said:

This is a new one on me Mike, made me do some reading. Veegum's a close mineralogical relative of bentonite eh? I

Yes; they are very similar; the main difference being that bentonite clays have additional salts and minerals in it, while the Veegum is close to pure aluminum, magnesium, and silica oxides. Like bentonite, its particles are very fine; colloidal in fact. Veegum acts as an adhesive  for refractory bodies In the green state, and then allows them to  sinter bond during firing.

I stumbled accross this information when looking up zirconium silicate on DIGITALFIRE.COM ; this is the most straightforward source for ceramic information I have found. Someone had written an article on using Veegum to turn zirconium silicon into a moldable high end refractory, but he or she  wasn't mentioned by name, so I couldn't site the original author, and I had to repackage the information, since I don't think  anyone here is interested in pottery. Although, I am a lot more interested in the subject after reading him or her 

It was you who got me more interested in zirconium silicate than in stabilized zirconia. I couldn't find out enough about the material to satisfy my curiosity, and so kept on looking for more. Veegum would appear to be the perfect binder for both forms of zirconium.

[Mikey98118]

You can get a pound of Veegum T for under ten bucks through the raw materials section of Seattle Pottery's e-catalog.

That would be Seattle Pottery Supply

[Frosty]

I've done some more reading, you're right about Digitalfire.com, great site I bookmarked it. There are a couple pottery suppliers close to me I'm going to give them a call and see if I can get some locally. On the other hand I'm out of Zircopax anyway, I should spend a few bucks at Seattle Pottery Supply, they'll flat rate even. GREAT folks.

Bentonite is colloidal. It's why it's used as drilling mud it stays in solution, only the cutting settle in the mud ponds and tanks, the clay stays in solution.

When mixing bentonite use a vein shear mixer not a paddle, propeller, trash pump, etc. Drill a 1/4" hole in the center of a 2" long piece of 1/4" x 1/2" or wider steel. Run a 1/4" bolt through it and lock it with a jam nut. Chuck it up inn a drill motor and have at it. The flat trailing edge of the shear causes cavitation which is violent enough to mix darned near anything in fluid. 

I imagine it'll work just fine with Veegum as well, they aren't that different. Any broken clay will absorb water and distribute it until the water content is equal throughout the . . . batch, formation, farm field, etc.

The easy way to mix DAMP bentonite is to spread it evenly in a plastic tub and spray the % water you want on the surface. Close the lid,  come back in a day or two and check. Trying to physically mix 3% water bentonite will drive you nuts but it'll temper itself.

Okay, I just spent some time on the phone and none of the pottery suppliers or ceramics places have even heard of it. It's Seattle Pottery Supply for me.

Thanks for being your curious old self Mike.

Frosty The Lucky.

 

[MonkeyForge]

I was looking for properties of bentonite and found digitalfire, also stumbled on veegum, non of my local ceramics suppliers carry the veegum though. I am in the process of building a new forge and want to run some tests before I start the actual build. I may try using plane bentonite clay I can get at my supplier. I think it is a white firing one which has less non desirable minerals in it. At 3 to 5 percent it should not matter too much anyway unless you are worried about the whiteness of your porcelain, at least to my understanding. It will be interesting to see the difference between different mixtures as well. I intend to test:

- bentonite + zirconium silicate
- bentonite + kaolin clay + zirconium silicate (5%, 20%, 75%)

Not sure yet as whether i will use plain water or water/rigidiser. May use both. Note that the instruction for bentonite is to mix dry then add water/ fluids. for veegum mix in hot water as Mike cites.

Also: Mike, thanks for jogging my memory on an unusually quiet day at work. Forgot how much I love chemistry.

[ThomasPowers]

We used to buy bentonite at the feed store it's an additive for cattle feed...

[MonkeyForge]

Yeah the bentonite is easy to find, it is in a lot of brands of cat litter as well. the veegumm is a branded form of it, also purified as I understand. In all forms pretty cheap as in most applications it seems to require a very low percentage mixed in with other components.

[Mikey98118]

Guys, you really should take the Bigitalfire.com tour, starting with zirconium silicate. I condensed what I found; but the guy did several test objects, and what he came up with, separates Veegum and bentonite's results by a country mile. Considering that Veegum goes for only about a third more, and how small the amount of this binder plasticizer is in the formula, all you are saving by switching to bentonite is ease of purchase, while what you are losing is a whole lot of thermal cracking resistance; bad trade, that!

[Mikey98118]

The percentage of re-radiation in zirconia coatings is directly linked to the size of the zirconium dioxide particles. Crude particles can go as low as 70%, while small particles can reach 93%; since half the mixture is silica, that 93% figure gets cut in two. BUT, we are talking about re-emission--not reflection. For about every .040" thickness of zirconia, or more probably, every .080" of zirconium silicate, another 46.5% of the heat of conduction gets re-emitted back toward the inside of the forge. So, we find that a hot face refractory layer of Zircopax and Veegum is going to not only take a lot of heat and mechanical abuse, but it is also highly insulating. Not bad for a moderately priced homemade refractory!

[Mikey98118]

Frosty,

You will recall that the author of the zircopax/Veegum refractory article noted that by 5%, the Veegum binder creates a stick mess of the refractory. But, I am thinking that "sticky" is a good quality in in a thin hot face coating, yes?

[Frosty]

1 hour ago, Mikey98118 said:

Frosty,

You will recall that the author of the zircopax/Veegum refractory article noted that by 5%, the Veegum binder creates a stick mess of the refractory. But, I am thinking that "sticky" is a good quality in in a thin hot face coating, yes?

Oh yeah, my head is spinning with ideas. I'm really interested in it's effect on Kast-O-Lite-30, as a plasticizer it's also a lubricant so might make casting multi outlet burner blocks easier and yield better results. It'll take a little calculating though being so similar to bentonite you can't mix it with a water setting material and expect good. Being colloidal though I'd mix it with the water I'm going to use for the refractory.

I"ll have to measure everything and I usually eyeball mixing Kast-O-Lite.

Thinking about it though, you live within driving distance of Seattle Pottery and love to tinker. Maybe I'll see what you come up with before I start tinkering. 

I'm not the only one in our club excited about Veegum since I mentioned it, we'll probably do a club buy.

Frosty The Lucky.

[MonkeyForge]

Cannot find a source for Veegum T in the netherlands (easily ) I can find Bentone or bentone.  Both are brand names in US, but when I look it up here it seems to be a name for a refined hectorite. Digital fire names Bentone(EW) to be an alternative for Veegum T and what I can get here is the same chemical composition as they (digital fire) list. I will try  a mix as I am experimenting anyway. Mike, any thoughts are welcome. any test results from your end also.

[Mikey98118]

MonkeyForge,

I think a lot of your decision would have to depend on what you plan to cast. At 3.5 % one pound of Veegum would go a long way. What is the shipping cost for that small an amount?  from somewhere in Europe? Can you get it from China, where they do everything possible to keep shipping charges low? China is a big exporter of ceramic materials...

4 hours ago, MonkeyForge said:

Cannot find a source for Veegum T in the netherlands (easily ) I can find Bentone or bentone.  Both are brand names in US, but when I look it up here it seems to be a name for a refined hectorite. Digital fire names Bentone(EW) to be an alternative for Veegum T and what I can get here is the same chemical composition as they (digital fire) list. I will try  a mix as I am experimenting anyway. Mike, any thoughts are welcome. any test results from your end also.

that seems fair enough; I can think of a few things I'd like to mold from this stuff, along the lines of burner blocks. you may have finally found a way to get me to try multiple flame nozzles; along the Giberson line though. I think this stuff is tough enough to make them worthwhile. Also, I would like to see if vibration would be enough to get this refractory to slip cast; that would open up a whole world of possibilities.

[Mikey98118]

I inteded that last answer for Frosty.

[Frosty]

56 minutes ago, Mikey98118 said:

I inteded that last answer for Frosty.

Which Giberson? There are a number of them. My next multi outlet burner will tell me if shape means much in performance. I ran the current NARB forge at Art on Fire last weekend in June and it was almost windy. The only time a burner even sputtered was when a gust blew directly in the forge opening. Running above 2psi and it didn't backfire once even when a gust of wind cranked the back pressure up.

A friend wants a button or square one, we just haven't gotten to yet. 

I'm betting Veegum T will make a number of differences getting the Kast-O-Lite past the crayons. AND if it sticks one layer of refractory to another like they say it will I'm thinking a layer of mostly bubbles between the burner block's largely Zircopax flame face and the rest of the block as a heat shield. Maybe do lost wax and make an evacuated space between flame face and main block. 3%Veegum, 97%porcelain will fire air tight. Hmmmm? 

I can't stop brainstorming this stuff! It won't stop giving me ideas! It's like I have a brainNado! 

Oh, the definition of "thixotropic" says mechanical agitation: shaking, stirring or vibration will make it do it's . . . thing. I still haven't read enough about thixotropic to understand that bit of neatness but it's one of the things that makes Veegum so good at whatever it actually does.

Frosty The Lucky.

 

[Mikey98118]

At last, I have coaxed Frosty down to the deep end of the pool! Alas, I've ended up there with you

It is exciting isn't it; finally a new (to us) ceramic product with a thousand and one uses, which is actually available to mere mortals, rather than only to titans of industry!

Yes, the "sticky factor" of 5% Veegum should make Multi port burner heads easy to mold in two parts, and then glue together. Their extreme thermal toughness will make the heads practical for forge work. Your ribbon burners are likely to take a big step forward.

However, the big concern about using propylene in my fuel/air hand torches and equipment burners, just went bye bye too. Next thing coming up is commiserating with each other over the amount of forge makers who accidentally become steel founders without half trying. Still, where would we be without problems to overcome?

Why do I get the feeling that a practical alternative to high alumina kiln shelf floors just turned up? Of course, this stuff is going to turn oval and "D" forge building into child's play, and end the search for 1/4" high alumina tiles to protect square forge insulation...

I think we just entered into "interesting times. "

We all will need to keep track of every source of Veegum we can find, and asks others to post any sources they come across; nice long suppliers  lists on Veegum T and Zircopax are going to be wanted by people who can't find them locally.

[Mikey98118]

We don't want to forget humble ordinary bentonite clay either. I will be looking into mixtures of bentonite and Perlite for use as lite weight castable secondary insulation, bricks, etc. Waste not; want not

[MonkeyForge]

Hey Mikey,  being able to find and afford the Veegum T is not really my point. For me it would be ok to ship it from elsewhere and I could probably afford it (and be willing to pay for shipping.) the next guy on my side of the pool may not have that luxury. I just found another product which is used for the exact same application that we can source localy and easily at a reasonable price.  I was hoping you had some experience / insight. I intend to test the Bentone (not Bentonite but refined hectorite) on my end so we shall have that experience. At the very least we can compare notes :). I was very impressed with the 98 % zirconium silicate crucibles I saw on digitalfire, made with veegum, bentone is named as an alternative. That said, thanks for the pointer and let's stay in touch.

[Mikey98118]

I am easy to find right here, and I also answer emails. Next step will be looking into Bentone. Yes, what he said about building thermally tough crucibles rocked my world too. It immediately sent my imagination into overdrive about using this stuff as high temperature burner nozzles and muti-port burner heads. In the past, using word searches on the various types of crucibles, had been my main source of PRACTICAL information about refractories; now such searches can be cross referenced on Digitalfire.com. It's been a very good week, thus far

[Frosty]

I  know you addressed Mike in your last post, I hope you don't mind if I butt in. I do have experience with bentonite clay and will have to do more reading about it as a ceramic additive. Bentonite is  a hectorite and  can be had in as refined a state as a person wishes to pay for. I'll have to do some reading and see where Bentone falls in this large group of mineral clays.

This is a large class of clay and will take some time to develop a grounding in it so I know where to look for details. I see Mike is off on a similar track, we're writing at the same time. . . .again.  I'm only 1 hour behind him in the time zone game so it's not a big thing talking in real time. Holland is what 9 hours ahead of me so it can really slow things down. 

I sometimes forget about time zones and can be short with people when I should just add a day to response times. If I do that with you please just tell me. Okay?

Back on topic. I don't know how useful one of the bentonites will be as THE matrix for making burner blocks, nozzles, etc. It has such a high firing temperature it just might be beyond our practical means. I don't want to have to make a kiln that can survive an Oxy Propane burner heat source to  get bentonites to vitrify.

From the little I've read bentonites are used much like Veegum T and the down sides don't matter to me. I don't care if it discolors my forge liner. What I care about is how it effects the refractory's working characteristics. I'm currently using a water setting castable refractory which means it has a limited working time once you mix it with water, 20-30 minutes before it starts setting up. KastOLite refractory behaves like Portland cement bonded concrete because Kast-O-Lite uses hydrating calcium crystal chemistry to stick everything together. If a % of a bentonite clay or Veegum will make Kast-O-Lite more workable in it's limited working window, flow better, more plastic, etc. then it's a BIG BOON. 

If you will PLEASE experiment with Bentone and post your results for all to share! I am NOT in any way arguing one product's superiority over another's. I do NOT suffer the "Not invented (or whatever) HERE" idiocy. I don't care where a superior . . . thing comes from so long as it's legal and not ethically bad. I want to know about it anyway.

Oh, as a last request. Do you have a name or term of address we can call you by, Monkey Forge is a little weird in my head. I can adapt though. 

Frosty The Lucky.

[Mikey98118]

My take on things is along the same lines as Frosty's.

Going by Digitalfire.com's materials section, there is a long list of purified Hectorite clay products; all with one kind of advantage or another. However, they are all likely to come with limited availability, just as Veegum, which the author calls the king of binders, does. So, starting with bentonite clay, the purer products will have to be researched area by area, to see how good a plasticizer/binder is available in each.

On the other hand, bentonite clay should be available in most places, and will due handily for many purposes; just not for crucible or flame nozzles. I too look forward to what you can come up with locally. No doubt many sources of Veegum and other refined binders will be listed here, as more and more people become interested. But, this subject is going to take people all over the globe, and many years to even make a good beginning at answering these questions.

[Irondragon Forge ClayWorks]

In one of the threads (can't remember which) you asked for suppliers. Here is the supplier that we use. They are in Nixa, MO not but an hour away from us. They will get anything asked for and ship everything if needed. The site has a great list of MSDS for supplies.

http://landrspecialties.com/