35 inch Pompeii Oven Build Saga

[Greenman]

Re: 35 inch Pompeii Oven Build Saga

There are probably pros and cons for both methods. I have just done a week of curing fires without insulation and other than some fine cracks there was no issues. As the firings progressed the cracks settled to the extent that they closed and stayed that way for the last fire. It wasn't until the 3rd fire that moisture could be seen in places on the exterior of the dome and when that evaporated off after a couple more fires it was a good indication of progress.

I am presently waiting for the vermicrete to dry before applying the render coat. I expect that steady fires will be the way to go for the first few fires after it is all done.

Like David said, you don't really know what is happening under the insulation but it will probably assist in moderating the temperatures.

Cheers............. Steve

[david s]

Re: 35 inch Pompeii Oven Build Saga

In retrospect, since I let the oven dry naturally for >>several weeks, I would have been inclined to think it is better to do the dome insulation first before firing because it might have helped distribute and control the heat across the oven more evenly.

Brett

I agree, One of the problems of driving out the water with no insulation on is that there is a big difference in temperature and therefore expansion between the inner surface of the bricks and the outer surface which is a condition that is inviting cracking. The blanket will moderate this problem to a large extent. The trouble is it makes it difficult to inspect the outer dome surface to check for cracks once it has been covered in blanket or vermicrete. Plus the blanket will hold some of the moisture being pumped out of the dome. Remember, if you see visible steam then you are going too fast, let the fire die down.

[Burns wood]

Re: 35 inch Pompeii Oven Build Saga

Great build thread, after looking through your build, I don't know if it helps build confidence or scares me more,

[Rickaroonie]

Re: 35 inch Pompeii Oven Build Saga

A newbie here and first ever post. I've been searching and researching for awhile now. I thank you Mistertoy for your photographs. Very detailed and leaves less questions. I'm about to start my build. Have most of the materials for the stand and will start in the next week thanks to your pics.
Rickaroonie

[Laurentius]

Re: 35 inch Pompeii Oven Build Saga

Hi Mr. Toy,

Do a few more firing before insulating, drive off as much moisture as you can.

[irelande5]

Re: 35 inch Pompeii Oven Build Saga

Heard someone say think of cracks as self adjusting relief cuts, kind of like that, you eluded to it, no surprise part of the build, nice work, look forward to more pics

[Mistertoy]

Re: 35 inch Pompeii Oven Build Saga

A few more photos for your entertainment. Well went on to a larger fire the next day. Got a little tired of feeding the fire and maybe heated it up a little to fast and the dome started to clear.

Surprise surprise - a few creaks on the outside. I was a bit "dismayed" at first but the creaks just follow the brick joints and look worse than they are plus are only evident/visible only on the outside, not the inside.

Anyway, thought about grouting then up but decided they are narrrow really creaks that are just part of the natural expansion of the oven. So went on with wrapping the dome in three layers of ceramic insulation.

In retrospect, since I let the oven dry naturally for >>several weeks, I would have been inclined to think it is better to do the dome insulation first before firing because it might have helped distribute and control the heat across the oven more evenly.

Just have to finish the enclosure walls and make a door now !

Brett

[Mistertoy]

Re: 35 inch Pompeii Oven Build Saga

Well finally got around to posting some more photos...

I decided it might be easier to build the roof frame on the ground and lift it up later - I think it was a good way to go.

With the roof on, I did the sheet metal work around the flue pipe with an outer box from cement fibre sheet and filled space with vermiculite cement.

You can see the windkat chimney cap I got from ebay, one of the best buys I have made.

Before I started a fire, I had to divert my attentions to some oven tools. First of all a poker and metal rake to drag out the ashes. I have a flat and curved rake in mind plus a mop, brush and metal pizza peel. Will get some photos soon... pretty fortunate my Dad is a retired welder.

Finally have a little fire in the hole.... ended up using wood because I could not wait any longer (to arrange for a gas burner or heat beads). I found it quite difficult to maintain a small fire, had to continually feed it with small quantities of small twigs to keep the temperature down. It still got hotter than I had aimed for and the heat was a bit uneven between the floor, sides and top.

Next batch of photos and commentary coming soon.

Brett

[Mistertoy]

Re: 35 inch Pompeii Oven Build Saga

Nice job Brett.

Where did you get the 230x230x75 firebricks?

From Claypave, but I haven't seen any on my last visits. Give them a ring, I am sure they will have some stashed somewhere.

Brett

[harro]

Re: 35 inch Pompeii Oven Build Saga

Nice job Brett.

Where did you get the 230x230x75 firebricks?

[Mistertoy]

Re: 35 inch Pompeii Oven Build Saga

Here are a few more photos from a few weeks ago...

You can see the heat break I have put in between the front decorative arch.

I am working on the roof enclose now and chimney through the roof. Progressing fine just takes time fitting everything in place. Hope to have a few more photos next week.

Might even be able to light up soon !

Brett

[UtahBeehiver]

Re: 35 inch Pompeii Oven Build Saga

Well, I see you chimney cuts match your dome cuts, you are setting the bar pretty high!

[Mistertoy]

Re: 35 inch Pompeii Oven Build Saga

Just a short update with photos

First couple of photos of the chimney transition - pretty happy how I was able to shape it to be smooth - worked out better than I expected. Used a 4 inch grind with diamond blade and it was quite easy but time consuming and dusty. Smoothed out the transition with some course wet and dry - overkill I know
I am going to use a 6 inch stainless steel flue and fit it inside the top of the chimney bricks by say 2 inches or so. So I shaped the bricks to form just over a 6 inch hole. I actually used fire brick offcuts and cut then to same thickness. One more layer to go but I don't really need to go that high but since I have the bricks cut I will do it anyway.

After I finished the chimney brickwork (you can see the old shape that resulted from using offcut pieces), I did the front landing using coping pavers.
It is hard to see by the photos but I have left a about a 3/4 inch heat transfer break - I will fill with insulating material.

Next will be doing outer brick decorative facing which go on top of the landing pavers - photos to follow !

Brett

[UtahBeehiver]

Re: 35 inch Pompeii Oven Build Saga

Brett,

Your joint cuts are over the top in tightness. It looks like your time and patience paid off. Great look. Thanks for the info on the plug, will incorporate in my clousre. Great job.

[Mistertoy]

Re: 35 inch Pompeii Oven Build Saga

Thanks for all the great feedback everyone, it is appreciated. Just hope that the photos help someone as all the posts that I read really helped me.

It has taken over a year to get this far and sons keep asking when they are going to get a pizza !

If I had my time over, I would not have been so fussy about have tight joins but once I had the first several easy rows done, I did not want to change.

Russell - about how I got the angles for the cuts ?
I ended up using cardboard templates mainly because it was a lot faster and easier than my original method of guessing and trial and error trimming.

So I will try to describe... I traced on a piece of cardboard the bottom angle then marked the angles for sides and top then cut out the cardboard shape; placed the cardboard template on a firebrick (remember to flip the cardboard over otherwise you will get a mirror image instead ) and marked around the cardboard then it was a simple matter of cutting with a diamond blade dropsaw. Any minor "final fit" trimming was done with a hand grinder with diamond blade. I started with only using the grinder but found the dropsaw heaps quicker, easier and gave cleaner cuts.

Using this method while it seems over the top, it was really easy to get the most out the firebricks and was quite quick with little need to trim.

The last plug was easy I held a piece of cardboard from inside the oven and with some coaxing (to climb up) my wife traced the shape from the top; cut and flipped the template and marked out the bricks then cut with the dropsaw and that was it with minor trim fitted perfectly.

All the best
Brett