2024 Neapolitan oven build

[Giovanni Rossi]

As others have stated, great masonry!

nlinva referenced my keystone is made of 2 standard firebrick. I just buttered them with a thin layer of mortar and clamped them overnight. A round keystone would have been fine, but I decided to try making a 12 sided one. I'm not sure which shape would have been easier because I had only an angle grinder to work with.

One point to share was that I trimmed and dry fitted the stone a number of times and settled on it resting about 1/4" below the last course. I could have trimmed it a bit more. I was surprised how much room the mortar took up and had to push it out and remove mortar 2 or 3 times. You can see that the joint it pretty tight. It took a bit more persuasion by my wife from above with a rubber mallet than I would have liked to get it in place. But, it sure "locked" everything together.

[daidensacha]

MarkJerling, UtahBeehiver

Thank you for your kind words, it means a lot given your status as experienced builders.

It’s been on my bucket list for 10 years now, since I first obtained the Forno Bravo plans those years ago. This last year I dove into Sketchup drawing and refining details, working out how I would do it. There is no experience like actually doing it though, and I gained a deep respect for all those who have done it. It’s hard work, working through problems and issues. I’m so glad I spent the last year working out details, and planning. Honestly, it would have been a disaster had I not. So far, it’s falling into place, and I’m trying to balance enjoying the process with the desire to finish it now. The two kind of work against each other, and I’m now leaning more to enjoying the process and it will be finished when its finished.

[daidensacha]

One more course leaves an awkward size hole for the keystone.

New batch of fire cement very different to the first lot I used.
I ordered a 25kg bag of fire cement as I ran out on Tuesday, and the supplier let me down. They didn‘t deliver so I ordered what looks like the same product from an alternative supplier and the bag was delivered yesterday. From the photos, and information provided I expected it to be identical, but it is very different to work with. Very easy and fluid, yet not runny, and grey instead of reddish black. The work time is much longer, and it reacts very differently when in contact with the Schamottsteine. It does not become instantly hard and unworkable when in contact with the Schamottstein like the precious bags. It is more like what I was expecting to start with.

That said, the weather this week has been overcast, cold and wet, with max temp today 13C, min 7C. I did the second last course yesterday, and cleaned it up this morning as the cement is still not set. As the horizontal gap was a bit bigger on this row I inserted slithers of Schamotte in the cement, and much easier with this batch of fire cement.

Anticipated size of Keystone hole to fill: ID 115mm, OD 145mm, is this to big?
As I come closer to the keystone, I‘m presented with an awkward size hole to fill. I have one more course which will leave me with an inner diameter hole of 115mm. On the outside this will be around 145mm diameter. I do have 2 extra 250x250mm floor Shamottestein, which I could use as I would be able to cut them big enough to fill the hole in one piece. I would need to cement one on top of the other as Giovanni Rossi did to make his keystone. I don’t see and alternative, other than to do one more course, which would require me to cut the width down from 64 to 40-50mm to allow a very small hole to insert a small keystone.

I‘m open to feedback, or suggestions if anyone has some experience with such an issue.

Adjusting width of IT brick holding plate as the bricks reduce in width.
One other small issue I didn‘t anticipate was the 50mm wide holding plate on my IT. It was too wide from this last couple or rows of bricks, so I was positioning my bricks to the side so it didn‘t impede the positioning of the brick, This messed with my angles though, and I only realised when finishing this last course that I need to cut the width down to 20mm so I can position the bricks on center, and this should do away with the problems I had these last courses of the angles. It’s ok, as I individually cut one side of each brick as I test fitted it to see what adjustment I needed to make. But I could have avoided this altogether had I realised earlier that I needed to reduce the width of the IT brick holding plate. Hopefully documenting this helps someone else if they encounter the same issue.

[UtahBeehiver]

Yes, I had to do something similar to the IT

[daidensacha]

Yes, I had to do something similar to the IT

That looks very much like mine now too. I hit it with the 125mm cutting blade to reduce it to 20mm wide today. It should do the trick for the last course.