DIY Refractory Glue and refractory brick 4600 F 

People have mentioned trying experiments with: Aluminum Oxide, Perlite, KaoWool, and others. I also thought of adding to the list Bentonite Clay, powdered or granulated carbide, or even a commercially available high temperature refractory compound like Cement Carborundum Mortar. Also graphite powder is a high temperature additive in some high heat applications. Most high temperature mortars are the silica-aluminate type and they may be interesting as additives as well. I think you're onto something with your lime/water glass based mixtures and look forward to more videos.

Now these are the videos that're worth my time

Every time I'm looking for something your videos come up. Awesome stuff. Thanks a ton

Genius!! Thank you for sharing your knowledge and experiences very appreciated it here 👍👍

That's an awesome accidental discovery Bob! Thank you for sharing that with us. Definitely you should consider selling it, it looks very useful and superior to many refractory materials. Other high temperature resistant materials I've seen and used for a carbon arc furnace and pretty much all of them were very brittle, you could look towards those avenues, but your material seems far superior. I've also seen those "Starlite" type materials popularized by *NightHawkInLight* and others on RU-vid but those actually puff up and burn as a carbon foam on their surface. I look forward to your experiments, from all my reading and observations you are at the very top end of materials that resist heat yet retain strength. Carbon-Carbon as it's known in the high speed military aircraft industry is the only thing superior as far as strength, but it might have lower temperature resistance than even your material. I've been wanting to melt this Niobium metal I have for years so if you do end up selling it I will be one of your first customers. Thanks for all your information and excellent videos.

wow bro, nice stuff... looks good, gonna have to try some of that.

Thank you So much for sharing this with us - Much appreciated!!! Melt Happy Pour Safe! 😎

Amazing. Well done and thank you for the knowledge. It's valuable. Cheers J

I think you got it. The expansion and retraction of the metal will weaken the bond. The concrete though holds it well even after heating and cooling... good job and many thanks.

Hi, Thanks for all your videos and this particular one. I followed it all the way through! Very interesting. I will be trying lime with silicate as it is one combination that I have not yet tried. (I have some garden lime leftover from an attempt to make refractory cement, that was a failure.) You may find that for an extra hot-face coating on a furnace, a thin coating might work best. I use a similar silicate coating made with talcum powder, aluminium oxide and iron oxide (Just for a dark colour). I paint it on as multiple thin layers onto stainless steel to give it more protection when burning charcoal within tiny forced-air stoves. The thin coating works best as it seems to be able to expand and contract with the heat expansion and contraction of the SS which is very considerable. It works as an expanding crack filler by itself. It also makes a wonderful expanding refractory when painted thinly on aluminium cooking foil and stuffed into a hole. It gets hot, fumes, expands, oozes and bubbles off hydrogen gas and cures itself. It can be hurried along with a flame, so you should be in your element! I too have had no success with sand silicate refractories. They fail badly on subsequent heating or just with the lapse of time (very good for casting cores). Pure aluminium oxide mixed with a little silicate makes a rock tough refractory as does the garnet waste grits from the sump of a water jet cutting machine. I don't have a hydrogen flame to test them, but they just laugh at repeated cycles of the hottest temperature that I can produce when they are heated in a thick bed of charcoal in a forced-air furnace or forge (Way above the max temp of 1300C K-type thermocouple. A similar dirt cheap silicate refractory can be made with subsoil from my farm and a nearby park (loamy clay free soil from post hole digging or crab hole mounds if you are feeling lazy). I mix perlite or vermiculite with this post hole soil and silicate to make a lightweight insulating furnace refractory with excellent insulation (way over 1300C on inside and harmlessly warm to touch on the outside). Its remaining weakness is that the vermiculite (or perlite) starts to melt (turn to glass) somewhere above 2200F (~1200C). That is where I would like to try your lime silicate as a more refractory coating to prevent this melting. Here is a video of the furnace: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-PIDgGCa4iUM.html You or your followers may be interested in more details of my exploration of a long list of silicate refractories on my website: timtinker.com/diy-refractory/ or my DIY furnace made with silicate timtinker.com/diy-wood-charcoal-furnace/ Thanks for sharing your ideas and I will add lime to my silicate refractory list. Tim

I think this is very interesting! TY for sharing! I want to coat a rocket Mass Heater with it.

been real busy lately cant believe iv b on missing out on these

so interested in buying some looks so good so far

There is a product called 'Heat Fence" it came in a 12 or 16 oz jar, it was a pure white 'putty' . It remained pliable and reduced the propagation of heat past the barrier of the material, so once the heating was done, the material could be put back into the jar. I like the adhesive characteristics of what is demonstrated here. A material to stiffen or reinforce it might be a glass fiber, carbon fiber, or a product called 'Thermo Felt' from J Tillman co. Great to see some real science going on.

great stuff I also will use my old sand blasting material and there's always a maintenance on my forges all take the old stuff that crumbles of and break it up and mix it into the mix and it last a long time . I been playing refectory for awhile. and feel I got it down I definitely keep it basic I keep it stupid simple

you can also make Aluminium Oxide yourself and add it to the mix. a lot of handy videos out there on how to make that stuff, did it a few times myself, pretty easy. i would recommend you to keep all pieces of scrap Aluminium you have and convert them do the oxide so that you will basically have an endless supply.

Such interesting stuff. This glue is very impressive. I can see many applications in blacksmithing and knife making. Just thinking/wondering what a mix of the glue and perlite would perform like. may help bulk it out as a refactory cement.

Nice product

Very interesting

I'm so glad you've shared your results! Have you experimented with using this "glue" as a cement to hold silica sand together, as you did with the sodium silicate cores? I'm not quite sure I've heard you mention this during the video... Seems like it could make a good bulk refractory. (If kept dry, judging by the comments.)

As for advice i reccomend Zircopax plus somme bentonite. Or alumina with bentonite like 5-15%. But it will take a lot to dry depending on how much bentonite you add. I would also add 1% by weight toilet paper fibers to the mix. Zircon( zircopax) its more refractory than alumina,much more heavier thogh and a few times more expensive. You can buy these materials at ceramic shops ,like pottery shops.

I have mixed aluminium powder in with refractory cement and the caustic in the cement causes the aluminium powder to react and make hydrogen gas and make the cement aerated. The problem is it’s an exo ther mic reaction which dries the cement quicker than desirable and weakens it

I'd test for moisture resistance after firing. The limelight was using quicklime, which results from heating lime until it loses CO2 (check wikipedia for limelight). Unfortunately, quickline will absorb water and get to slacked lime which is not a good binder. Granted, the presence of the silicate in the stuff may divert from part of the lime-quicklime-slacklime reaction path, but the content of silica is too low to bind the entire calcium. If the material crumbles after fired and then absorbing water from air, it can still be useful when you don't mind reapplying the protective coating (i.e. "painting" a crucible) even if it wouldn't be necessary suited for long term without refreshing it.

I like this vidio- that might work good for a burn tube for my wood powered truck- I like that strength test- though ceramic blanket is lighter, if coated with pure water glass- though that stuff looks excellent if you can combine some insulative properties to the mix- as long as its stronger than ceramic blanket,it would work for part of the burn tube , in a wood powered truck, there were over 1 million vehicles powered by wood during several war time frames due too gasoline shortages.

if you want something add to the mixture, common sense tells me first choice to try would be material that makes cruisble and torch tip. say aluminum oxide? those purple stuff that makes your tig torch tip. you can get them from any old aluminum casting, or those "white fire bricks", that's pretty easy to find and smash to power. be safe, pal.👍

Hey bob, I have an idea, take your hardest refractory available, as probably is this stuff, and cast a pedestal with 4 to six upqard pointing feet, if you will, so the crucible you put in a foundry is resting on a few points with enough space for decent circulation between said feet. The floor of the foundry could be carved out to bury the support disc underneath.

Watching this I am wondering if vermiculite (puffed mica) would work as a way to bulk up the mixture plus stiffening it somewhat. Addition of the mica may limit how thin you can spread it but it may make it more structurally sound. If it was warmer in the shop I would go out and try it myself...will have to wait for spring now.

You got some interesting videos, and a cool ebay store Just to note- 200grams of water is equal to 200ml of water, which also takes up a volume of 200cubic centimeters or 2cm x 10cm x 10cm =) i.e 1kg of water=1liter=1000cubic centimeters/10x10x10cm cube

I've goofed around with some refractory-making ingredients that you may find of use. Primarily I was interested in making my own graphite, which was completely successful, though two of the experimental refrac materials were also a win. At the temperatures I'm pushing it acts more as an ablative material, but if you were going to cast iron or something a bit less intense, It should hold up just fine. For a hint, look into how roman concrete was made, it'll provide a lot of insight for your projecting mix. You've got most of the mix already, just missing one ingredient which, unless you live next to a volcano, is a bit hard to find. I'm trying lava rock which is hit and miss, but if you can find pumice for a good price, it works too. I ran out of traditional methods where I could get extreme heat to break it down (over 6000*F), so I ended up getting a plasma cutter to really see where it can go.

Nice, TY for sharing. So it's pure liquid water glass and calcium oxide? What percentage? I'm guessing that liquid water glass is just water and sodium silicate?

Yes Sir!!! *THANK YOU!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!* 💯💯💯💯💯💯💯💯💯💯💯

I agree and like the clay and graphite ass a addative

Est ce que je peu l'utiliser pour faire une dalle réfractaire pour un four thanks for all, you are a gentleman

When I worked for Pillar Industries we made huge industrial induction heat treating/parts handling robotic systems. The main units utilized in the foundries were for smelting and creating various molten steel and aluminum blends to pour into sand molds. Refractory coatings were utilized to reflect heat inward and insure a proper barrier between the molten metal and the inductive coils buried in the Refractory that was used to melt the metals.

do you have a material breakdown and the correct mixing amounts to make the glue compound.

Whats the trick with curing it? Ive made water glass few times this last time with the garden lime and still cant get it to harded

What is the working time for this sodium silicate/garden lime before it sets up? Or, do you have to cure it with heat or co2?

great video, do you think it would suit gluing insulating fire bricks in a rocket heater riser. Thanks

Does it matter if it is dolomitic or calcitic lime?

Hi Again, Looking at your great video a second time. Is that broken glass tube fused silica glass? Is it softening in the hydrogen flame? If so, I think that the lime/silicate refractory is surviving at about 2,000C (3,632F). Do you think it is that hot? Tim

try silica gel or add aluminum foil and make alumina silicate i think aaluma is used in other areas of refractory

Longer crystals make things stronger so use longer crystal water glass or add it to that. I would also try Epson salt

Try making some starlight material and experimenting with that. Might have to blast it into carbon first before mixing up with anything.

How good is this for insolation

How well would this hold up against molten iron?

I would measure your refractory glue for temperature expansion and contraction, anyting I added would be to get that number closer to whatever your painting it on. expanding and contracting A different race is probably what's making it come loose from the metal. As far as the water glass sand cores, I was told they fall apart at high temperature so that when the metal shrinks as it cools it breaks the sand rather than itself. they are intentionally designed to do that to work correctly inside a green sand mold. You also want to be able to remove that core when you're done casting the metal so it helps if it falls apart on its own

Add some titanium dioxide or tungsten oxide to the mix. My forge i coated with water glass and titanium dioxide

I would try to make it more porous.. atm it more is like a "liner" something to smear on firebricks to make em last longer.. but if you wanna make a brick out of it.. it should be more pourous. :)

So it can resist really high temperatures but how good of an insulator is it?

You've got precious discovery out there, can it be used as crucible?

Your coating on homemade refractory brick: Could it be used to make a foundry that can melt scrap iron, in addition to copper, tin, brass, bronze, aluminum, and zinc?

Interesting, the lime should give off CO2 when heated, like Starlite, which will react with the waterglass. Too bad you didn't weigh a sample pre and post burn. If you want stiffness, just put some stainless steel shavings in the mix. This stuff seems pretty cheap, so it could do as an outside liner of a furnace where weight isn't an issue, since the lime is sensitive to acid.

Sorry if I missed it, but............if you were making a castable refactory mix (not the glue) your mix would be "what?" with waterglass. ratio's? Excellent on your glue. Basically I am talking a casting for a rocket stove, so wood placed every day, with temps in the 2000 degree range, then cooled down.Daily maybe the problem, year after year.

It might be interesting to add calcined kaolin clay and diatomaceous earth to your mixture to stiffen it, adding those two things would make a geopolymer. Be careful with diatomaceous earth dust ie a respirator is needed when handling it.

Not sure if I missed it but what's the proportion of water glass and lime ?

Any pointers on making homemade firebricks. Bought a pellet stove and the firebrick is missing. Replacements are spendy!

Phenomenal bro. Maybe carbon or graphite based substance to enhance an even mixture. You got a good discovery.

What are the rations of water, lime and water glass?

Grams and milliliters of water are the same thing on room temp.

I’d be interested to see what you could do incorporating equal parts vermiculite clay(cheap kitty litter) and prebaked and ground clay ie ceramic like tiles pottery or simply the fired clay as a powder, I feel like it would make a foundary liner like play dough, if you add something fibrous as well that should help prevent cracking working like a binder? If you give this mix a go keen to see the outcome!!

EDIT: It's not necessarily CSH, Did you add water? If yes, you've made CSH, basically regular cement, so probably not CSH. But if you only add waterglass, then you probably made calcium silicate. Wikipedia said Calcium silicate has a melting point of 2400 kelvin, which explains why it can withstand oxyhydrogen torch. The torch has a burning temperature in that range, which can be higher or lower depending on the nozzle. It is quite solid, with reported strength of 10 MPa, 1400 psi. If you don't mind testing, make a "geopolymer". It also uses waterglass, but instead of the garden lime, it uses heated kaolin clay. You can buy kaolin clay and heat it to 1400 degrees F, or buy "calcined kaolin" directly. It should be stronger and have a smoother finish than the material you made. Depending on your mix, it can be set anywhere between an hour to a day. Also, you kinda have to mix with a mixer, because it's very viscous and it would be very tedious if you hand mix it. But geopolymer can only withstand about 1200 kelvin, which is half of your material. If you decide to make a structural component that is heat resistant, you may choose geopolymer as its strength is about 2000 - 7000 psi, but if you only need insulation, this is a great material. Thanks for sharing!

@ NOBOX7 I have watched this video and your one about best sodium silicate proportions. You have had some of the recipes harden in the jar when storing, sometimes overnight. Something to think about this. Sodium hydroxide after opening the container easily absorbs carbon dioxide. Carbon dioxide cures sodium silicate. So if you make the sodium silicate solution with sodium hydroxide which already has carbon dioxide in it, that could be curing in the jar when storing. The sodium hydroxide used must be a freshly opened new jar. Just think that is possible. I wonder if heating the already opened sodium hydroxide could make sure there is not carbon dioxide in it? Blessings

How does it work with cast metals? We all know how hard it is to weld and though JB weld works ok. In high heat like exhaust manifolds its lacking at time. I can see using a coarse steel wool to aid in vibration strength. On any cast automotive part. Even holes in mufflers. No down time taking it off and having the manifold welded that isnt always a fix as these welds can be hit or miss. We all know that medical cast like crap muffler wrap sucks as well.If its sandable and paintable then the use in the automovtive repair field will be great.

You should revisit this idea and add PDMS to your mixture. Silanes/siloxanes will decompose when exposed to high enough temperatures. When this thermal decomposition happens, since the polymer is made up of mostly carbon and silicon, what forms is silicon carbide nanofibers. I think it could provide a better structure to it. Carbon nanotubes could also do the same thing and they're aren't too difficult to make low quality nanotubes. Just strike an arc between two graphite electrodes submerged in distilled water.

Check that link see what you think

I'm a little confused. When I looked up garden lime, most sources said that it was calcium carbonate (essentially chalk), but you list calcium oxide in the description. Then there is quicklime/slaked lime/hydrated lime etc which is calcium hydroxide. So is it calcium hydroxide, or calcium carbonate? Thank you for considering.

Oxyhydrogen torch such big ? Be safe man.Doesnt worth to die for youtube.

@Nobox7 Nurd rage video shows 2 recipes for sodium silicate. 1st, 60g sodium hydroxide, 80g silica gel, 100g water. 2nd, 30-40g sodium hydroxide, 60g silica gel, 100g water. You were showing 200 water written on your cores. Very interesting refractory you have made though. Does it last? Does it absorb moisture from the air?

So garden lime and potassium silicate need to be cured with ambient carbon dioxide or will a blue flame work?

what foundry isnt carcinogenic? what is yours made of that isnt refractory concrete? are u referring to the airborne particulates?

Have a look at the Geopolymer institute the work of prof Davidovits he popularised concrete & other mineral based polymers made from metakaolin clay waterglass+ blast furnace slag fly ash or red mud,vermiculite or perlite can also be mixed in Im looking for a version of this that can be used instead of epoxy resin like the one being used in high end vehicle & aerospace.The chemical bonds are primarily silicon oxygen Aluminium so Alumino Silicate.

Could it be used to coat Kaowool?

I make my own sodium silicate, and I have some Hyrdrated Lime I bought at Home Depot. Mixed it as you describe and just 700f turns it into a weak crumbly material. As far as I know the Hydrated Lime they sell at Home Depot is the same as Agricultural lime you are using?

I'm interested about your hydrogen generation system.

Homemade water glass and perlite is what I made my forge out of. Of course it has its limitations. That and I was dealing with a back injury when I made it. 5 lumbar surgeries, 3 lumbar fusions later, and I'm back at it. I can't wait to build my next one. Paint can forge was the first. The rest became rocket stoves. I can't wait to get another mig welder. Built 2 wood gasification systems, rocket stoves, and a kiln with the last welder. Son in law left it in the rain. I guess it's lucky for him I as a disabled vet didn't just squash his head lol. Now I am left using JB Weld. But I guarantee I'll engineer a whole new system.

Nice Video! Try exposing it to moisture or water after cooking it red hot before doing any investment as a product.

Will it patch and exhaust pipe?

Guys the metal is stainless steel . If it was steel it would of burnt a hole threw in under 5 seconds. And thats quarts not glass

What is waterglass?

hey! 3rd ingredient; basalt fibers!!

Can you add the recipes to the comments?

Firebrick isint supposed to be dence the best fire bricks are super lightweight and "fluffy" feeling they dont just withstand the mass ammount of heat they allso insulate it could try adding somthing like vermiculite( melting point around 2400°F) or perlite (melting point around 2300°F) to both reduce weight aswell as add insulating properties in the production of ur own bricks

maybe magnetite as 3rd ingredient

plus I'm poor boy shop try to recycle everything I can

Graphite powder

11:14 it can be

Excellent find! Thank You SO MUCH for Sharing! 🙏🚂🎼🌹🎵🎶🛠 ~C< 3)>>-Z->}

I'm calling BS on this! I have tried several different times, varying the waterglass / lime ratios AND 3 types of lime - hydrated lime, dolomite lime, and plain lawn lime. Nothing even came close to what is shown in this video. Nothing hardened - it was just a sticky mess. Save yourself some time and try something else!

ᵖʳᵒᵐᵒˢᵐ 🎊