Perlite vs Vermiculite for DIY Firebricks (Comparison)

[@DavidWilliams-wr4wb]

I use either plaster of Paris and perlite or hydraulic cement and perlite and it’s hands down the best , easiest, strongest forge and firebrick material I’ve used , I have good luck with it , I mix it 50/50 and it works great, at 1.5” thick I can hold my hand on the other side with direct torch contact for an hour and more, great stuff

[@blueberry766]

And howmuch water in your 50/50 mix? And what about sand? I will make it and add Steel wool to act as rebar and strengthen the structure, am trying to make a melting furnace and a forge

[@DavidWilliams-wr4wb]

cement all it is a hydraulic cement, there is a brown bag and blue bag , use the blue bag for your mix , i didn’t use steel wool, you can though , you can also use metal rods or copper , I used 10 gauge wire cut into lengths that fit the size of what im pouring, that with the hydraulic cement will work fine , just follow the bag instructions on water for a wet mix if there is a little too much water it isn’t a worry because when hydro reacts within minutes it gets hot and pushes excess water out rapidly, just use the brand available at home depot called cement all with blue lettering , brown bag will work good too but the blue bag is better

[@blueberry766]

@@DavidWilliams-wr4wb thanks 😊 was your forge a coal forge or a gas forge?

[@DavidWilliams-wr4wb]

@@blueberry766 gas , I want to make a coal forge for summer though

[@JustSkyler-pt1fq]

Thanks for making this. I am researching to make a pizza oven and this is exactly the kind of info that i'm looking for.

[@foodrelated]

My advice would be to start with cob. Clay, sand and straw. Cob ovens are inexpensive, kind on the environment and are easily made. A great stepping stone to other materials.

[@JustSkyler-pt1fq]

@@foodrelated Thanks for the advice, I will be sure to look into it.

[@theinvisibleartists4444]

I just unmolded my first casting of the Pearl Light and white Portland cement. With the 5 -2-2 mix. It's 1/4 of the front of my glass furnace door. I found I had to mix a little extra because it was settling so perfectly. The mold side down is as smooth as glass but the top side is a little rough like this video. It is extremely hard not falling apart at all. So far this looks great! I'll let you know how the rest of my furnace build comes out. thank you

[@foodrelated]

Fantastic! You can always sand it to make it smooth. Just make sure your wearing a mask and in a well ventilated area (outside is best!).

[@AS-ug2vq]

It will crumble when exposed to several cycles of tmepeture over 600*C. Use calcium aluminate cement instead of portland cement.

[@mikelongo9123]

I use an old Fire insulating mixture in my Pizza Oven. It has lasted over 20 years up here in Ct. Nasty n Damp freezing Cold Winters. I built my oven as a barrel shaped retained heat type. Used a 3-2-1 formula of Perlite/Vermiculite a 50/50 blend, Pre wet before mixing by volume. 2 parts sharp mason's sand. One Part Portland or white Portland cement. This mixture is applied over the assembled firebricks [ 2 to 3 layers, just keep going around n working up] & then after a day or three of drying coated w a Sparge coat of mortar . After a few slow low & careful fires The whole "Igloo" was painted w a stucco type paint.

[@l0I0I0I0]

Hey Mike! Wanted to be sure on your formula that lasted 20+ years? 3 parts mix of 50/50 verm and perl; 2 part sharp mason sand; 1 part Portland white cement? Wasn't sure about the rest? Coat the brick or pour with white Portland three coats, then white stucco? What kind of stucco? TY!

[@mikelongo9123]

@@l0I0I0I0 Portland is Portland. .The color won't matter. After the Sparge coat/maybe 2 times, Portland/sand/water mixture is applied. Seal the Sparge coat layer w Stucco or weather proofing paint. Cool ? I'm Building another oven out in Western Pa. it is going to be covered with all local natural stone & mortar. We are about 40% covered. Lots of hard work for us old people, some retirement project. Best of luck to ya buddy.

[@l0I0I0I0]

@@mikelongo9123 TY Mike! I love doing these project and I like to get creative with it like. May throw in some thermal mass, a cold smoker and an oven for slow cooking a turkey 🦃! I don't mind the hard work but I must see in my head the design from beginning to end.

[@l0I0I0I0]

@@mikelongo9123 I see, 3/2/1 is Portland, sand and water. I did not know! TY.

[@mikelongo9123]

@@l0I0I0I0 The old 3 2 1 mixture, is the Perlite Vermiculite insulating concrete. The Sparge coat is is portland/sand & enough water to applie easily. The weatherproofing paint applied last can be almost anything you have laying around. Cause up here the oven needs a roof over it to protect it from getting wet & then the freeze thaw cycles it must endure. Protect your hard work.

[@analogdistortion]

Hi Tom! To compare weighs you can weigh both and the use water displacement to find the total volume of each of them.

[@foodrelated]

analogdistortion thanks will try that in future.

[@analogdistortion]

@@foodrelated Yeah put one container onside another or on a tray and fill the inner one then when you put a brick in you collect the water that immediately spills out and weigh it. One millimeter is one gram.

[@ironkid8836]

Thanks for this want to make my own forge will try the perlite myself had made one previously with just fire cement

[@truckerenoch8824]

This isn't very useful (or accurate) comparison if the crumbly one has sand and the other doesn't. If you have a video with equal recipes, but perlite in one and vermiculite in the other, please link it.

[@Shafiq1969]

Should you use standard cement or any special heat cement for the perlite mix? Thanks

[@kayyumgeliyeahh]

Any answers?

[@moonolyth]

Portland wont last long, and if using it.. Id mix it heavy very little water. I was into bronze casting a time ago we had a special mix for plaster molds. You would melt the wax out and pour hot metal into. I can find the recipe if you wish excluding plaster, and replacing with what you are using as a binder. the mix contained Perlite, for isulating, Vermiculite for vacillating, and sand for strength keep in mind this was in a mixe for plaster not cement. But I think the idea is to produce a hard surface that flexes with temperature fluctuations. This mix was a one-time-use but if replacing with another binder the properties may be what you're looking for in the right quantity recipe. Another easy to make product would be glass water and that would make a fantastic binder to. Also perhaps not with cement-based material but with good fresh plaster you don't use tap water.. minerals in tap water solidify much quicker.... use evaporated/ condensed water.

[@foodrelated]

Thanks for the info.

[@dogprowilhelm7630]

Try omiting sand in the mix, crumbling the pearlite about 1/3 by volume and use about 1/3 uncrumbled pearlite with Portland cement. Water glass seal the pearlite for thermal cycling. I call it 'Space Crete' and is good in my DIY Tandori Oven up to 900deg.

[@Lonchpad1]

what do you mean, whateglass seal the pealite? you put waterglass on the pearlite before mixing with concrete? does the waterglass harden/dry on the pearlite? I've tried adding waterglass to my perlite portland sand mix and it immediately makes it unworkable, hardens it. Thanks

[@dogprowilhelm7630]

After mixing the water, cement and Pearlite pack and let dry in your forms for bricks, blocks, or shape you made. Initially cure for a minimum of 2 weeks, then seal with Waterglass and let dry additional 2 weeks before heating. This will give cement a full 28 days to fully cure and lessen chances of cracking. Hope it helps.

[@Lonchpad1]

Actually, I found that I can pour the pearlite in Portland. Mix into my form and fire it in an oven to about 500° right away and it will dry just fine.

[@theinvisibleartists4444]

Thank you very much for this video. I'm building a glass blowing furnace, and have been scratching my head about what mix to line the inside of my furnace with? After ordering two bags of perlite and two bags of white cement I'll soon start casting. Again thanks for this video.

[@foodrelated]

Thanks for watching. Good luck.

[@mike-ology22]

Thanks for sharing, I'll be trying this for a pizza oven and rocket stove

[@foodrelated]

Sounds great!

[@theinvisibleartists4444]

I've cast the main door for my furnace and my plinth. So far this is remarkable!

[@foodrelated]

Thanks for watching

[@luciusirving5926]

The only lightweight concrete aggregate I get here in Mexico is pumice, but it's a great insulator for the price.

[@foodrelated]

Great alternative.

[@daddyyddad1]

En México también hay perlita y vermiculita

[@kenniffss]

Have watched a few of your videos now. Good stuff. I'm thinking of building a kamado type bbq with this method. Do you reckon it would work?

[@jarodmorris611]

Interesting that you didn't use water glass in your mix as a binding agent. I like the recipe. I purchased firebricks but only got 10 (got the 9x4.5x3 instead of 9x4.5x2.5). so I'm thinking of making the base of my heat treat oven out of perlite. I have had the perlite in the rafters of my garage for 3+ years. It's time to use it :)

[@RRaucina]

I have a garbage can full of perlite outside and open for 26 years and it is just the same as the day I bought it.

[@RRaucina]

Can I mix perlite with waterglass or potassium silicate to make a insulating board? Mix it and then fire it to bond it?

[@jarodmorris611]

@@RRaucina I'm no expert, but I would think that would work. That seems like what people do with perlite now for firebricks.

[@elijahsexton4380]

I wonder if you could put diatomaceous earth in the mix

[@johnsanchez8029]

Dude! every time I pass the bag of DE in my laundry room, I wonder the exact same thing. Hahaha. Tried it since you posted?

[@smithramsey3188]

Oystar shells?

[@soullimbo]

Thanks for the video and information. Would I be able to use a colour dye if making these bricks?

[@DarkMoonDroid]

If you could have a do-over, would you add the sand to the Perlite mix? If so, what would the ratios be with the water?

[@ClydeBickford]

I'm a concrete novice, but if I were planning the mix, I'd use plaster sand as it adds a granularity the perlite doesn't have, far smoother finish I'd think.

[@brett7794]

I have feed back. I recently discovered if you want a safe either it will be fire resistant or actually be burglary proof so i decided to make a fireproof canister to go into my 1/4 steel safe because there is no such thing made for this purpose I'm have trouble trying to figure out what to plaster around with this mix u made but I'm open to suggestions it needs to be 7" x 12" or smaller I'm thinking a pvc pipe with end caps on both ends?? With this mix on the outside and stuffed with perlite inside

[@WALLACE7084]

This Perlite is it the same stuff they also use to mix in the soil with plants. I want to make a furnace and when I look for Perlite it always seems to mention it for plants.

[@foodrelated]

I buy mine from a horticulture place

[@WALLACE7084]

right so it is the same stuff then.

[@TheGamingGeek01]

This is a really off topic question, but are these substances toxic when mixed together with concrete? How does it react when heated next to food? I just thought about that LOL. Great video!

[@silviofontana3666]

I thought that a few simple testing examples would have secured your message. Withpout testing, this product can not be seen as effective, but understand you have undertaken your own testing.

[@foodrelated]

Yeah lots of experience and testing was done before this video and I probably should have talked about it more.

[@jessalford5927]

I just lined my red brick wood fired kiln with mortar mix and vermiculite mixed together to form a plaster that is 3/4th of an inch thick. It stuck really well and so far no shrinkage. Some say mix it 50/50 but I mixed mine 60/40 with the 60% being mortar mix. We will see how it goes after firing. 80 dollars is better than fire bricks at around $225.00. I believe it will work just fine, we will see.

[@garethrobinson1729]

Good video but what's the mix I'm trying to make a firepit will it work with normal Portland?

[@foodrelated]

Yep 3:1:1 Perlite: Portland:sand

[@mattsparkes834]

Hi Tom...thanks for your fire brick and oven videos. I'm making a rocket stove from DIY fire bricks. What's your recipe for perlite bricks please?

[@crazydan777887]

Hi, would you have a recommendation for perlite size. I found different sizes, would larger be better?

[@foodrelated]

Unsure, I use medium P400

[@crazydan777887]

@Mauricio Daniel what does that mean

[@springbloom5940]

@@crazydan777887 Its a spam bot

[@youknowsomething7235]

Do you have any reccomendations to make faux logs, skulls or balls for fire pit or fireplace?

[@lambofwrath95]

What exactly do you mean by white cement? Is there a specific (non branded) name for this stuff? Wanting to see where to buy it in AUS

[@foodrelated]

You should be able to get some at Bunnings. Just ask for white Portland.

[@lambofwrath95]

tompeyton1 legend :) thank you

[@jirirawadzanai2057]

@@lambofwrath95 Portland is not good for fire it can break masonry is fire resistant since it is not white im lost which type is being referred to by the speaker

[@williamknecht7922]

How many liters of Perlite would it take to mix with one 25kg (55-lb) bag of cement at your 5-2-2 mix? You've said repeatedly this by volumes, but cement isn't sold by volumes. Refractory cement costs $100+ USD per bag, so we need to know this to estimate larger jobs. Thanks. I really like your videos.

[@foodrelated]

I would estimate 200 litres, given that when we made the last oven we used around 100 litres of perlite for half a bag of cement. I haven’t made one with refractory yet so I’m assuming it would be similar amounts to Portland cement...

[@toaluasaleupolu7060]

Thank you for the video 😁👍

[@foodrelated]

No problem 👍

[@kovko69]

How about white cement w/ vermiculite, and sand w/ perlite? How would they rank and perform compared to the two other variations you show in the video?

[@foodrelated]

The white cement(percrete was harder for sure)

[@victoryfirst2878]

What is the temperature difference between the two bricks ??? How long will each last with rough treatment ???? Thanks

[@foodrelated]

Haven’t actually tried a controlled experiment. Anecdotally I would say perlite (percrete) is harder, and retains heat better.

[@gustavosatlari4202]

Im starting with my oven, y bought the perlite but i cant get white cement here in argentina in quarantine tima. Is the same if I use the regular grey cement?=

[@foodrelated]

Yep all good

[@theinvisibleartists4444]

From what I understand the white Portland has a higher quartz content. It took me two months to get my white Portland cement and perlite block fill. I don't really know but I don't think it would make that much difference but we will see. I start casting in three days and I have both cement so I'm going to try both and I will come back to this feed and post results. Thank you

[@jeremybenwy5928]

Plaster of Paris-play sand and water😉your welcome

[@CobusWillemse]

What is the mixture for the perlite firebrick

[@monkspride1]

did you use refractory cement or just portland?

[@foodrelated]

al hernandez Portland

[@RRaucina]

Anyone have a recipe for making a very high heat resistant perlite board bonded with potassium silicate or water glass? Like the ones used as baffles in wood stoves...

[@ferretface8782]

Are these mix ratio parts by weight or volume?

[@foodrelated]

Volume

[@robertthomas7644]

not a good comparison the sand is the difference try both with and without

[@ryandemosthenous3917]

And also. The cement ratio is different...

[@JonathonNeville]

I want to create something like your perlite firebrick, except it doesn't need to be used near fire, and it needs to minimize density and therefore hopefully won't have any cement. Is it possible to make perlite retain a shape like this without cement?

[@saarpaz4584]

Parts ratio are by volume or weight please?

[@foodrelated]

Saar Paz volume

[@ErbleAdam]

Just used the white cement and perlite to make a fire brick for my wood burning stove. How long would you recommend leaving the brick to cure before exposing it to any heat? thanks

[@foodrelated]

2-3 wks

[@pierrec.dussault2138]

Why is there an emphasis on white cement over standard grey cement for the perlite brick?

[@foodrelated]

I like the pure white finish

[@gap9992]

I'm planning on making some "planks" of perlite / cement mix to use as a surround behind my wood burning stove. I'll bond them to the wall. They will not be getting very hot as there is a space between the stove and the wall. I want to achieve that sawn board finish that people use with concrete. I'll put some mesh in to reinforce the planks and use sawn boards for the base of the mould. I think I am going to need to use a wetter mix and some fine sand in the mix to get it to take up the sawn board finish. Anyone got experience of this or tips please?

[@stevefarable]

I like your idea, I want to do something similar but you had no response so far.

[@foodrelated]

Sounds like a good idea. Adding the sand will help the finish i think.

[@NathanNostaw]

Only one mention of the actual purpose of thr material, insulation, and that was anecdotal. Every other property mentioned is either irrelevant or wasnt an equal comparrison. I dont need a fire brick to he crash tested or handle vehicle traffic. It needs to insulate and last many heat cycles. EG. Kaowool. Great insulation and lastes for ages in high heat cylces, yet doesnt have any other the other prperties mentioned in this video. All the other properties only hecome relevant once the first 2 are sorted.

[@snowflakemelter1172]

Ever tried welded wire mesh in the bricks as a reinforcing ?

[@foodrelated]

No I haven’t but it sounds like a good idea

[@razony]

I wonder if that's NOT a good idea. If the metal in the brick expands, so will the brick. That's my hypothesis.

[@pierrec.dussault2138]

As said by others, this is not good. The metal will want to expand significantly with the heat, whereas the rest of the brick will not, causing it to crack. This type of reinforcement is used in concretes or plaster mixes where the metal expansion will not be significant enough to be problematic (temperature changes will not be big enough). Therefore especially not to be used in a forge. Some people on KZbin have used them, but it is not a good idea.

[@tomkelly8827]

I don't think that metal is a good idea because it will expand but I think that fiberglass fibres could help in the same sort of way without the expansion issue.

[@edwardpadilla7543]

You never mentioned what you mixed it with

[@foodrelated]

A spade and hoe by hand.

[@Next72Hours]

Would this be ok for a base for a wood.fire.oven for the cooking surfice?

[@foodrelated]

It’s not the best but that’s why we use pizza trays. Smooth firebricks would be best but more $$

[@ronwalker3000]

What is WHITE cement? I notice there is no sand in the pearlite mix, is this contained in the WHITE cement (mix)?

[@foodrelated]

Ron Walker no, no sand in the mix

[@mikefennema5561]

Are your ratios by volume or by weight?

[@foodrelated]

Mike Fennema volume

[@winstonsmith935]

Perlite originates from Volcanic rock. So it was born in fire.

[@dikhed1639]

What about a mix? did you try a mix of the two?

[@foodrelated]

I haven’t mixed the two...yet!

[@mikedoth]

Will the Perlite brick stand up to weather/rain?

[@foodrelated]

Mike H it has so far, but it’s only semi exposed with a roof over the pizza oven. These bricks you could store inside...

[@b69ker1]

Hi, what little would I need to make a medium sized pizza oven?

[@foodrelated]

Just use a smaller inflatable gym ball... maybe 50 litres

[@juligrlee556]

Perlite is mineral and does not absorb water like vermiculite

[@brett7794]

I thought concrete was not to be used in high heat applications because it can blow up at 1100 degrees

[@davidgleeson9225]

Any body mixed the two ites together for a laugh...And thanks

[@foodrelated]

Not sure maybe try it!!

[@ropehitch]

Yeah, just watched a video by Make It - here's the link kzbin.info/www/bejne/aHjWZ61jYsyAh80

[@jpculirroti63]

Hello good video, I can not find information on perlite and refractory cement. do you think it can work better

[@foodrelated]

Im sure it would work. Refractory would allow fr higher temperatures, because as many have pointed out the constant fluctuation of temperatures will cause the Portland to crack as it expands.

[@menardsoni1425]

Hi there. Can anybody recommend an online shop that sells perlite ? Preferably one that ships overseas because I cant find a seller here in my country that sells perlite on 40li to 100li quantity. They only sell small packs and they're too expensive

[@foodrelated]

Try Amazon.

[@DarkMoonDroid]

Garden Suppliers.

[@tomkelly8827]

It is light an fluffy, the shipping costs woud be quite high to order it, better to look at a garden supply place

[@mrtechie6810]

Look for a garden center. Too expensive to ship by air.

[@analogdistortion]

What's the ratio you used? I need to get my rocket stove and BBQ built

[@foodrelated]

analogdistortion both ratios are in the description

[@ClydeBickford]

Completely unfair test. I think perlite would still win in a fair test, but the difference would be far smaller.

[@LuisLopez2]

Vermiculite retains water. Perlite does not.