36" Pompeii Build in the desert

[jim lofaro]

Hi all,
Just about to get stated on a 36“ diameter Pompeii WFO. We built a 4” concrete hearth that will be insulated using the 2” FB insulation board. Is the 2” FB board sufficient for insulation?

[UtahBeehiver]

Welcome to the forum. As far as insulation, it depends on exactly how you will use your oven. 2" of CaSi in the minimum amount of floor insulation, you can cook pizzas and have enough residual heat to use the oven the next day for roasting or baking. If you are planning on extensive bread making you will need more insulation and thermal mass (floor and dome). If you want to extend your residual heat then additional floor and dome insulation will be required. Another inch or two of CaSi would be great if the budget allows, an alternative is to pour a perlite or vermeculite/cement (5-1 ratio) first then lay the CaSi board on. Most important, make sure the floor insulation extends under the dome wall. Good Luck.

[jim lofaro]

More questions:

So my thought is to follow this build:

https://drive.google.com/drive/folders/0B5uCdOP-Vn44U0Zxel9rb1UzQVE

The problem is I ran across this photo log months ago and cannot find it again. It would be nice to see some other ‘words’ to go alone with the pictures.
One change I was gonna make to the above design is putting the cooking floor inside the dome. The Pompeii instructions seem to favor this idea:

{{{
As an option, you can cut the firebrick floor to fit inside the oven dome, rather than having the oven dome rest on top of the cooking floor. The advantages of this approach are that it allows you to replace a broken or worn out floor tiles, and it offers better thermal performance.
}}}

Any thoughts?

I am planning the purchase of a tile/brick saw but would like it to accommodate the ‘chipster’ style jig (https://community.fornobravo.com/for...-table?t=16780)

Will the 10 inch Harbor Freight or Kobalt work?

[JRPizza]

Jim, there is much debate on setting the dome on the floor vs around it, but there seems to be agreement that replacing a brick is not something that is done very often. I am getting a little wear on the bricks right at my opening from the weight and tight fit of my door, but I could replace most of them if I needed to.

[jim lofaro]

Many thanks for the synopsis JRPizza. There is so much information out here i tend to fall down the rabbit hole.

After viewing your build my plan is now to step back and pour a 2 inch perlite (or vermiculite) insulating layer for the FB board to rest on. I like the added height. Any thoughts/recommendations?

[JRPizza]

Not from me. I had thought about pouring an insulating layer but ended up getting enough CF board to provide a 5" layer with very little excess, so I didn't feel I needed to supplement the insulation under the floor and the additional 5" height put the floor about where I wanted it to be. Lots of other builds used vermicrete or perlcrete for insulation though so if you poke around you will find lots of information on ratio's and mixing techniques.
You might already know this, but I find the site's search engine lacking, so I usually just run a google search using the following format, for example when I was looking for landing size information:
landing size fornobravo site:fornobravo.com
You can put the search term in quotations which will only return the exact text, or you and search for x AND y (capitals for the and) to find posts with both terms only.

[jim lofaro]

Thanks ever so much for the search tips JR. You would not believe how many browser tabs I have open.

Is there a trick for uploading photos to the forum? I get a message saying my photos exceed the limit.

[JRPizza]

Not sure about the photo problem, but there is a tip my son taught me I use. I open the photos in microsoft paint (the original one) and resize them to a minimum resolution of 1080 pixels. When I resave them they are quite a bit smaller and I have not had trouble loading any of them.

[SableSprings]

Welcome Jim!

I've been surprised when I see the size of most photos taken with a smart phone or "real camera"...in terms of bits, they're pretty large. I try to crop (still using Picasa 3) and resize any photos I want to post or send as a courtesy to the service or person. I always let them know that if they want the original image, I'll send it to them...but so far everyone is happy with what I've sent out.

As JRPizza noted, Microsoft's Old Paint program (and the newer version) will resize photos. However, I use a free photo program called FastStone Photo Resizer which gives me quite a few more options than the Paint or Picasa program for the actual resizing. What I like about FastStone, is that I can select a group of photos and have them renamed and resized in a single batch operation. So I can pick out several pictures of my dome that are saved as DSC0235.jpg, DSC0239.jpg, DSC051.jpg for example, crop them as (or if) needed, and then rename them during the resizing operation as Dome01.jpg, Dome02.jpg, and Dome03.jpg

I've found that by going to 800x600 pixels in the resizing, my pictures get reduced from 2-3 MB to 100-200 KB ...pretty significant if you're sending pics to someone who doesn't have a high speed Internet connection. At that 800x600 pixel resolution, the photos look just fine on a full screen view...

Also note that here on the forum there is a limit of photos you can post at one time (currently 6, I believe).

[jim lofaro]

Allrightythen, let me try to resize and post. the form for a 1.75 inch layer of perlite/cement.

[jim lofaro]

and now with the photo

[jim lofaro]

after reading some of the 'things i would do differently' section my plan is to purchase another 2 inch insulating board. that would be a total of 5.5 inches of insulation (1.5 inches of perlite/portland and 4 inches of insulating board. My goal is to shoot for the no regrets category.

[jim lofaro]

the perlite/concrete pour and initial cooking floor layout.

[jim lofaro]

Still waiting on the 2 inch insulating board to arrive. The basic stats of my build include:

• 36 inch diameter Pompeii WFO
• 5 ½ inches of bottom insulation (1.5 inches of perlite cement 5:1 mix and 4 inches of FB board)
• 19 inch wide 12 inch high oven opening
• 24 inch wide vent landing
• WFO walls placed on the oven floor
• Herring-bone floor pattern
• The inner arch is built on 3 vertical bricks.
• The first course is a 4 ½ inch soldier-style layout

Questions:
Does the fireclay/sand mix have any adhesive properties that I need to be concerned about?

Any problems from sanding the floor once installed? From what I read it seems to be OK but some pitting has been reported.

Any problems with the basic concept/design that will bite me later on down the road?

Jim

[jim lofaro]

one of these days i will figure this photo bit out.