I used the perlite, fireclay, portland cement and sand mix and wow that dome is super solid

i can't believe i found this video, exactly what i needed

Thanks for posting. I can see from the video that you are working very hard and it should serve to alert the faint of heart how much work it entails to take something like this on. By the way, just as an aside comment, perlite and vermiculite are two different materials and, though they may be used in gardening in similar ways, they have different properties from each other and are mined from different rock formations, and should not be confused when making ovens or furnaces. Cheers!

I found all the perlite, vermiculite, and volcanic glass pebbles that you will ever need at hydroponic gardening stores. The volcanic glass pebbles seemed most promising.

Outstanding and very hands on in the making of a component

So far. So good! Keep it up. I'm about to go outside and do exactly what you're doing. 👍

Thanks for sharing your experience, I'm working on my oven and your videos helped a lot.

Helping advice for mixing in a wheel barrow. A mortar hoe is different tool than a garden hoe. Mortar hoes are heavy and strong, resisting breaking the tool. 1.alternate layers, the portland will always be the middle layer, to reduce the portland getting into the air while mixing. 1/2 of your agregate Portland remaining 1/2 of agregate A 6 cu ft wheel barrow can mix 4.5 to 5 @ 5 gallon buckets of dry material, plus the water. Premix the dry material, blending well. Mixing method: Grab the hoe as close the head as is comfortable, this allows you to apply more force while chopping and slicing through the mix, especially once the water s added. Starting close to you, begin chopping or slicing and pulling towards you little sections of material until all is mounded on your side. Now switch to empty side, slicing and chopping, pulling little amounts, moving from left to right across the mound of material, until all of the mix is mounded near you. Adding water: With mix mounded to one end pour 1/3 of the water into empty end. Beging slicing and chopping, pulling the material into and through the water, mounding it near you. If you run out of water part way through the mound, splash a little more. The pile should be damp, and not yet contain all of your required water yet. Mix through 2 or 3 times this stiff mix. Then add small amounts of water and pull through. At this point it is easy to add too much water, which would make the mix unusable. Once the mix is the consistiency of peanut butter you can add small amounts of water until you get to the point of miracle whip consistency. IMPORTANT: Wear gloves while mixing, portland will burn and cause small wounds on fingers.

Some sites recommend to mix the cement with the water and then doing the minimum mixing after the perlite is added to avoid breaking it up.

There's a lot of videos on YT for making Water Glass (Sodium Silicate), but I mixed roughly 4-5 cubic feet of perlite, 20 lbs of fire clay, 1 gallon of furnace cement and roughly 4 liters of water glass to 4 liters of plain water to make my rocket stove. Gave it all 3 days to dry, did a 2 hour burn on the 4rth day and left to dry more till the 6th day. Well that still wasn't enough b/c when I tried to lift it all, it kind of exploded under it's own weight. Water glass, though relatively easy to make, can get pretty expensive to make. The Lye is $9.00 for 2 lbs and Silica $15.00 for 5 lbs.

Thanks. Data that I was looking for :-)

Much easier to mix the perlite and cement dry then add water . lol

Helpful, thank you !

Appreciate the insight! Thanks! W

Big thumbs up for intelligent and useful feedback! 👍💪

Perlite and vermiculite are NOT the same thing. You want to use Perlite. Vermiculite will absorb water, which will turn to steam and crack the concrete when you heat it.

Thank you for your posting. Could you post the complete project please?

My next attempt will be to pulverize my failed cast and reuse the perlite and clay with 100% water glass, form bricks that will easily assemble to my specs, than fire each till they achieve maximum hardness. Then I can piece my core together and seal it with furnace cement.

My first time to, thanks for the video.

Hey Lee. Just wanted to say I've found your oven videos the most informative so thanks for sharing. I missed the detail of using Portland cement and used regular concrete. I'm able to walk on the perlite cement I made but I was wondering if you could somehow describe how hard your mix ended up being? Not sure if I can continue or if I should re-do it with Portland cement. Thanks!

Yes - I put a thin layer of sand first if I remember correctly.

Hi Lee! Greetings from Germany! Watched your great videos many dozens of times, beautiful work at all, learned a lot! Could you please tell me how the percentual mixture between perlite/fire cement/ Portland cement is and - did it got some cracks meanwhile? I´m building an oven based on a 16cm concrete plate, insulation with 6cm foam glas plates, 6cm refractory stones for the oven baking level and a dome made of fire concrete, instead like yours brick-by-brick (I´m a fool to make a dome with bricks :-) ). The upper part with the chimney I intend to surround with perlitecement like you, so I wonder how is the mixture for this? thenks & regards, Harry, Karlsruhe in W-Germany

do you have a video showing this mix with the liquid soap. would like to see it. in theory it sounds like a good idea. how much soap to other ingredients would you suggest.

I bought vermiculite at menards, its called mica flake in 3 cu ft. bags, can be used same as pirlite.

Hi Lee, Congrats on your oven and videos..They are EXCELLENT !!! I'm also in the process of building a pizza oven. Would you be kind to let me know what you use to attach the firebricks together ?? Are you using Portland and Perlite ?? Thanks so much. Chris from Orlando.

Good video, but I was dizzy watching it from the unsteady camera. All in all, glad I watched

I have always used masonry cement--has a F temp rating of 2100 degrees so adding perlite raises the temp rating--I have no idea to how high the temp rating is but I have never to date--5 years of cracking in my rocket stove/oven making jobs.

Great video, can you use a mixer instead of doing it by hand??

kool job man.refactory cement would've been better ,but this is how we learn what we can and cannot get away with.don't ever let people tell you that it can't be done because you don't quite have the write materials.I grew up in a family of masons that were like that and they never built anything for themselves."PS" the pearlite ,I would imagine helps disperse the heat more evenly than a solid crete pour ,because of the porosity of the mix.D. I. Y. it's" O KAY" man. if you were getting payed for the job however" error on the side of caution". I'LL SAY IT AGAIN EXPERIMENTATION IS HOW WE LEARN.---HUNGRY FOR PIZZA NOW>post by jd avery

would it work better if you mixed all the dry ingredients first making sure it is very well incorporated then add water to get the proper consistency just wondering

vermiculite and perlite are two completely different products.

Mixing it wetter would have made it a lot easier, especially if pouring in a form.

Curious, after 11 years, how had the masonry cement bound perlite held up?

That was great stuff. It's just me, but I would have mixed in some vermiculite. I've made gas forges with a mix of that and the perlite, some regular sand some cement. Vermiculite seems to be a bit better at insulating. It's what they use in brake pads, so yeah.

Thank you for posting. I'm trying to use perlite for oven foundation; howver the perlite I found in market is mainly sandy with very small balls max Dia is 5mm. It doesn't look like the one you using, Do you think size matter?

When working with cement you should first completely mix thy dry stuff - cement + perlite. Then start adding water and mix completely. The mix Should be as possible.

How's the oven holding up??? Thanks for sharing!

Yes, I still have some minor stuff to do but it's done for the most part. Stay tuned, I am going to put a video together from start to finish on how I built it. It will be mostly from pictures but I will narrate and explain what I did.

Try mixing up all the dry consistant and then the water - that is how they do it when baking a cake. and it is the way I was taught when helping my dad build a fireplace.

How is you 5 to 1 mix holding up? I'm working on my oven now..but not sure if the 5 to 1 is structurally strong enough. Any input or suggestion from you or anyone is welcomed.

Is this concrete refractory? Can i use it in my charcoal foundry?

Would you think it would be better to use Portland or that other cement you used?

what is the purpose of perlite concrete and where can I buy it? I am building my own pizza oven and will follow all your instructions and videos as they are excellent. Thanks for uploading it. I hope mine comes as nice as yours... :-)

My man,for starters u took onthe diy challange so "what u did wrong" is very irrelivant,comes very second to u doing the actual job,in my eyes u cant do "anything wronmg,major anyway!!!

Looks like weird stuff. Nice job.

Did you ever get it done?

Great job Lee. Can you tell us where you found the Pearlite?

how about a update on that oven may are curious to see how it turned out ..

Hi Lee. Beautiful work! Is the insulating concrete (Perlite+cement) sufficient for the floor insulation? I have seen in some video a guy has used a calcium silicate board in the floor insulation. I think it could improve the insulation but reduce the stability of the dome...What's your opinion?

Hey, I am about 1/4 through my pizza oven build and have totally lost all sources for refractory mortar. You are using Portland cement with your Perlite....correct? I am a total nubie in this arena but read that Portland starts to break down at about 450 F. Have you experienced any degradation or crack since you did this?

How did yours come out? I made a rocket stove without about this much water and it mostly stays together, but crumbles off all the time. I felt like I should have added more water...

I would mix the refractory mortar with the water first so to not fill the micro pores of the perlite with badly mix mortar mixture.

How thick was your perlite ?

Hi Lee, if you only wear DryFit shirts, you don't nearly sweat as much!

do you still have the oven? just wondering how it help up over time

you really needed someone else to hold the camera...i actually couldnt watch without getting dizzy...

Nic video

Hello, Great oven. Can you tell me what the outside temperature of the oven is when in use? Thank you

would that be good for insulating a basement floor on older home?

Perlite is white, vermiculite is kind of yellow, they are different materials, vermiculite is heat expanded mica a bi-product of china clay mining. Perlite is volcanic rock. They behave differently. Looks like you were using perlite, coz it's pearly white.

How thick do you think the slab would need to be build a fireplace on a wooden floor inside my house?

Thank You Mr. Lee for sharing the video, can you please tell me where can I get the perlite you use in the video and Fire bricks, I try with Home Depot and Lowes with no luck, I move to Saint Cloud Florida 2 year ago and I'm no to familiar with the area, Than You

Hi, can you tell me if it is normal Portland cement that you add to the perlite ? Or a refractory cement? Thanks

You did two things wrong: 1 Extremely important to mix dry parts THOROUGHLY before adding any water. 2 Your mix looked just right to me but you stopped working it too soon. Use a wood float or a darby (easy to make) and worked the surface it would have smoothed right out after a few minutes. Then, using a mason's steel finishing trowel, you can finish the surface to make it uniformly smooth and hard-wearing.This floating and finish troweling brings a mix of cement and fine suspended particles to the surface. (Masons call this "raising the fat"). I suggest viewing a "hand-finishing concrete" video on KZfaq. It could have saved you a lot of time and effort. It's easy to master.

The mix is 3 parts perlite 2 concrete sand 1 of istri40 head resistant concrete

What kind of cement should be use for in between the bricks please?

i'm big on calculating volume: basic math would get you their. I think you used a bit too much water. i made rocket stove (alot smaller project and much more ghetto than your fire pit) and my mixes appeared a lot more dry to the touch. i put the 5 gallon cans into a trash bag for amonth to let it cure. sadly, one 5 gallon rocket stove is still standing tall, the other one has crumbled from the inside out. i think i might have not mixed it good enough. good job though. your pit should be fine, make sure to next time let it cure longer and cover with plastic so it cures slowely

Excuse me, but can I ask you something? Won't the concrete generate harmful material when it's exposed on the temperature over 500 degrees Celsius?

isn't that going to crack over time???... should it maybe be done with refractory cement instead of normal portland cement???

it is much easier to mix the dry ingredients first and then add the water

what temp can it withstand?

I thought you couldn't use any Portland cement because it would crack when heated. I thought you had to use refractory cement. Am I wrong about this?

bit confused, are you using perlite or vermiculite, or are you mixing both of them? its just that you keep refering to both

Hi! How does this hold up over the years?

You must have said vermiculite 6 times in this video. Funny that I didn't see any.

Question Perlite over Vermiculite ?

Concret,mortar mix or only cement ?

my friend you forgot the Fire clay and a we bit of lime ,

How much Perlite and cement should I get to do the job?

Where did buy the perlite ?

All your dry material should be mixed before adding water

Where can I buy perlite.

Where can i buy some perlite?

Oh so this is the insulating foundation ... you build the clay oven ontop and I'm a pirate so motion makes everything clear for me lol

It cracked right.

Why 5-1 when lot of folks use 5 to 2 for more durability less cracking

È cemento refrattario o cemento bianco normale?

cement mixer?

I am getting motion sickness :-(((

No silica sand?

Winter Park Florida

What is the ratio

Where can we buy perlite

10 like

Side walks and roads could be made from this it wouldnt heat up as much in sun to help curve global warming or city ovens lol

How deep is it?

Perlite breaks down when you mix. ALWAYS use 25% to 30% more perlite than your volume calculations and TUMBLE mix don't mechanical mix or it will break down into powder...

I am trying to build a DIY Konro grill (Japanese table grill) similar to this one korin.com/Charcoal-Barbecue-Konro-Lg?sc=29&category=17859353 I was thinking of making a mold and using a perlite/cement mixture or maybe furnace cement to the mold and cast a grill. Do you think that would work or do you have any other suggestions?

So, the first batch: 2.5 buckets perlite, .5 bucket portland cement, .67 bucket water. (Never mind me, just taking notes)

@salbal777 I have found that finer is better