Finally decided on 32in castable dome

[Mullster]

18mths on - lessons learned / review

I thought it might be helpful to share a few reflections because it seems people are still viewing the thread.

The best bits:

• Finding this forum - what a resource is, what a community - by documenting my build I got support at every stage - and I needed it! Can’t imagine building the oven I did without this site.
• Casting an oven to me felt more accessible than a full Pompeii brick project for my first try. Especially given that I had very few masonry tools or experience.
• Building my base with 2 compartments accessible from the side I think is a good design. 1 compartment accessible from the front would have been too deep and therefore underused.

The harder lessons…

• For the base it would have been easier and probably a straighter result to use the hollow cinder blocks than pour in concrete and rebar. My bricklaying wasn’t the best. No problem with strength of the base - just not as good looking as it could have been.
• See my post 104 for some of the hardest lessons - using MDF in a wet environment…screws you can’t get to, casting in the heat - some tough lessons!
• When casting I think I could have taken more time to lay the home brew, really packing it down and then maybe had a smoother finish inside the dome.
• I also would consider skipping the newspaper. Grains of sand inside the dome are inevitable anyway and the newspaper was really tricky to control - especially with it being so hot the days I did it.
• I didn’t need to have an outer piece to the frame for my mould. It made it harder to remove and was unnecessary.
• Just buy the proper firebricks for your floor. If you haven’t already spent more than your budget by now, you soon will - don’t skimp on the cooking surface. I’m glad I went for the proper ones in the end but I wasted hours researching alternatives to try and save a fraction of the total project cost!
• Learning to build and maintain fires takes practice - you will get better! My fires now light easily, burn strong - it’s just a world away from those first few months of not quite getting them going properly.
• My glazing on the pergola is polycarbonate - clear glass like to look at. Second winter and it got a lot of condensation on it - so much so it caused quite a few puddles across the decked area and oven worktops. I was determined I wanted to be able to see through the roof and get the light, but I’m just not sure it’s possible to get a see through material that doesn’t condense….

Anyway - to any one not yet decided - BUILD - one of the best things I ever did - pizza will never be the same again - it’s just different level.

And to those part way through - your rewards will come!

[Mullster]

Warhorn6 sorry for the delay - I’ve not been on here for a while! You’ve inspired me to do a post on lessons learned soon.

So no problems with spalling. You might remember my inside of the dome started out not very smooth in any case - but it seems to be holding up well. I definitely have cracks in the dome but I think that’s fairly standard given the stress it comes under and I certainly don’t see any issues getting it up to temperature or anything. There’s one hairline crack on the outer stucco / render - but again it doesn’t seem to make any difference.

Like I say - full post on lessons learned to come but I can’t recommend highly enough the cast oven - really works a treat!

[Warhorn6]

Mullster Just finished reading this whole thread and learned so much. Thank you for posting such a detailed account. I'm currently in the planning stages of my build. Although i've been advised not to, im going to opt for the gym ball method. Was planning to reinforce the ball with paper mache and plaster of paris, wasn't sure if my idea would work until a few pages back David S suggested such a thing so now i feel a little more confident.

How has the Oven held up? Any issues with cracking or spalling at all?

[GrahamG]

Flue fitting, blanket fitting, vermicrete (again) and mounting the oven front

Felt like a real big day today. Started by creating 3 tabs in the flue to bend back enabling the mounting onto the cast. Whilst grinding the tabs took only a few minutes, the bending and adjusting took a long time. Two main reasons for this - the cast is not perfectly uniform so each tab is sat on a slightly different height of cast. Secondly the grinding and bending is hard to get identical for all 3. I really didn’t mind this process it just took a while. Lifting the flue, checking with the spirit level, lifting down and adjusting, again and again

After that I moved onto trimming my insulation layer of vermicrete under the oven - it was still protruding beyond the firebrick floor in a couple of places and I wanted a nice edge for the blanket to sit against.

I bought the 50mm blanket and it was pretty easy to work with. The Stanley knife cut through it well and I cut triangles out from the top edge so it would sit around the dome nicely. Used every last scrap so not sure what I’ll do for my door (seen a lot of people using the scraps for that).

I decided to use some chicken wire across the flue gallery which was where I had most of my off cuts wedged together so it helped to keep everything in place. I also put a section across the top of the dome which again helped to keep everything ‘attached’ to each other in terms of the flaps of blanket.

Next it was time to mount the oven front - feels like there should have been trumpets playing at that point! I used wire threaded through the hoops I’d embedded in the front to secure the front against the oven, obviously sat on a layer of mortar.

Lastly I made a start on the vermicrete layer over the blanket. More to do but hoping I can finish with a couple of short evening sessions early this week.

Massive thank you again to everyone I’ve learnt from on this forum - You’ve given Me the confidence to hopefully, hopefully, have almost built a good oven.

How did you get the chicken wire to stay in place?

[modified9v]

david s thanks for the detailed response. When I get ready to pull the trigger I’ll start a new thread in an effort not to hi-jack this one. This casting stuff is intriguing.

[david s]

If you look carefully you will see a wire running from the arch around the gallery to hold it in place. I stand the arch off from the gallery with a piece of cardboard (removed in the pic) to maintain a small gap.As you've noted there is nothing holding the arch other than the mortar joint between the arch and the supporting slab apart from that wire. Take a closer look and you will see I cast eight wire ties embedded into the cast arch which then get tied into the outer shell. This system allows the inner parts of the oven to expand and contract freely inside the cooler decorative arch and outer shell.

[david s]

Just finished reading your build start to finish. First off congratulations. Second, thank you for taking the time to provide a chronology of your project. I know how much work it is to put it altogether and share your highs and your lows as I did with my brick oven build in the Pompeii Oven Construction forum. The help we receive from everyone is amazing and priceless.

I came upon your thread as I am looking to do a castable oven for a mobile application. My pizza have been so well received in my community that I’ve been asked to bring the game to the local brewery. Your thread has been very valuable to me in this regard.

I do have one question: Do you, or anyone, think it is ok to make the Homebrew into more of a slurry, as in super wet and pourable so that it can be poured into a mold verses applied over the entire surface of the sand castle?

Thank you and continued success with your WFO cooking,
Mike V.

There are a couple of big problems with that idea. Firstly, adding more water to the brew adds more volume to the mix so when it dries it creates more shrinkage, resulting in a weaker casting that also may crack as it can't shrink away from the inner mould. The viscosity can be lowered by adding super plasticiser rather than extra water, however if too much is added it creates separation of the materials with the heavier stuff settling on the bottom and the finer material rising to the surface. Some experience with its use is required to get the addition just right.
The second problem with a lower viscosity mix is that it requires an inner and outer mould perhaps in several different pieces, as well as vibration to eliminate the air. This is the normal practice for casting in all kinds of materials, where multiple castings are made with the moulds being used many times. For a one off cast the work that this requires is just not worth all the extra effort. Experience in creating moulds is also highly desirable and it's doubtful that you could pull it off the first attempt.The material used for the moulds is also an important consideration as the casting process, especially with concretes, is particularly hard on the moulds. Don't even contemplate wooden moulds as they don't last more than a few castings before requiring repair or replacement. Fibreglass is better (that's what I use) but they also require maintenance and repair (about every dozen or so). Steel is the best material for moulding concretes, but the most difficult to fabricate.
By contrast the ball up consistency applied over a sand castle form to produce a one piece casting is both easy and cheap, with minimal labour required to get a pretty good result.

[UtahBeehiver]

You should reach out to David S our casting expert. I do know of a couple cases where builders made some fiberglass forms and did a slurry type cast pour. One was Iron Pony (he thread may of disappeared when the Forum was hijacked a while back).

[modified9v]

Just finished reading your build start to finish. First off congratulations. Second, thank you for taking the time to provide a chronology of your project. I know how much work it is to put it altogether and share your highs and your lows as I did with my brick oven build in the Pompeii Oven Construction forum. The help we receive from everyone is amazing and priceless.

I came upon your thread as I am looking to do a castable oven for a mobile application. My pizza have been so well received in my community that I’ve been asked to bring the game to the local brewery. Your thread has been very valuable to me in this regard.

I do have one question: Do you, or anyone, think it is ok to make the Homebrew into more of a slurry, as in super wet and pourable so that it can be poured into a mold verses applied over the entire surface of the sand castle?

Thank you and continued success with your WFO cooking,
Mike V.

[Mullster]

Looking great!
So did the laminate worktop come in that black and sparkle finish, or did you paint it yourself?

It came like that which was cool!

[Kris S]

Looking great!
So did the laminate worktop come in that black and sparkle finish, or did you paint it yourself?

[Mullster]

Worktops!!

Finishing touches (although I keep thinking of more to do) applied recently - I finally managed to install the worktops around the oven.

This was hugely important to me because I’ve been frustrated by having to spend my time indoors prepping the pizza while everyone else was outside drinking and chatting! This way now I can bring everything outside and do all the prep and socialize all at the same time.

Carried on the theme of sparkly and black for the worktops and in the end went for standard laminate worktop. I did almost go for solid wood but decided the regular oiling probably just wasn’t going to happen. Plus I really like the contrast of the black with the wood.

Cutting the worktops to fit around the oven was daunting especially as I was doing it with a half decent jigsaw rather than a router but to be honest I’m chuffed with the result. I’ll be filling the gaps between worktop and oven soon enough - haven’t quite decided what to use for that - possibly some simple render and then paint over....

Anyway - thought you’d like to see the final result - pizza parties have become the norm here now - just can’t wait for summer and for the COVID restrictions to lift so we can cater for more hungry friends!

[jfletch1305]

Thank you so much for posting such a detailed journey, it will be invaluable for me.

Do you possibly have a complete list of the quantity of items used for the oven itself (base excluded)?

Trying to workout how much of everything i'll need roughly.

[Mullster]

Pallet wood cladding

Well it’s taken a while - but I haven’t paid a penny for any pallets, although I will probably need to replace the broken hammer and mallet at some point that I broke smashing and prizing the pallets apart

Still got worktops to install around the oven - plus I want to board the final panel of the pergola behind the oven - but no rush!

[Mullster]

Aloha Mullster... I stayed up late reading your build last night and my heart sank for you, and for me when I got to the aftermath of your cast... I can feel you man.. you spend so much time and money you want it to come out killer... I was so glad you recovered... and was so happy when I got to your first pizza post... and seeing how much you enjoy it and how much every penny is worth it... well done for sticking it out... thanks for sharing... I am in the all in panic mode now ... way above budget... anxiety hi... I will be referencing your build and others for those little details... aloha

Boogie-D Aloha - glad you enjoyed my tale! I’m really glad I found this forum - no way would I have built my oven like I did without it - it’s helped so much.

Loving the oven - used it even with snow on the ground over winter but looking forward to the better weather and sunny days and actually eating the food outside without countless blankets! I’ll check out your thread now.