36" Beginner WFO

[danjmath]

Thanks for the input.
I am regretting my decision to buy a used tile saw, I could have got a harbor fright one new for about $10 more now, with it on sale, plus 20% off.
My pump wasn't working today. After about an hour of internet research, then a trip to the hardware store for some oil I finally got it going.
Boy, cutting that medium duty firebrick is like cutting through butter after those super duty Geneva Bricks. Found Gulfs post on how to feather the cuts for round ones. Was quite easy once I got the hang of it.
Got about 2/3 of the way done cutting the floor before it got dark.
Tomorrow I finish and try to figure out my IT.

[thevance53@gmail.com]

I use a small plastic container to measure out the parts and either use 3 parts sand or double the recipe for more mortar without mixing. That way I keep the raw ingredients apart and in their bags. I dry mix the parts in the bottom of a 5 gal bucket, and then add water. The mix dries out rather quickly so you need to keep adding water. The smaller the batches the less water you end up using and potentially keeping the mortar strength higher.

[deejayoh]

you can use any of the landscape/pond pumps at HF to replace a non-working pump. They're remarkably cheap!

[JRPizza]

Do some reading on IT design - if you can find the pieces that put the IT's pivot point and axis of rotation at floor level in the center of the oven, you can use what I call Gulf's wooden brick to replace one of your center floor bricks during your dome build.

[danjmath]

I leveled my cooking floor with 50/50 sand/fireclay before laying the CaSi board, but after laying the bricks, they still are not quite even. I am pretty sure it is the bricks themselves, they dont seem to be all exactly the same. Is this normal, and should I worry about it, or should I try and use more sand/clay to get them perfectly even?

Also, I have seen some people use a thermal break between the cooking floor and vent landing. What is its purpose, and how important is it?

[UtahBeehiver]

If you have some minor high spots (1/16" and less) an angle grinder with a diamond cup can smooth out the floor. Some builders have use a belt sander with a course grit belt, ie 80 grit. You just want to remove any lips that a peel might catch on when loading and unloading pizzas.

Thermal breaks are up to the user, the purpose is to reduce thermal conductivity from the dome and floor to the chimney vent and floor landing. It depends on what you ultimate cooking process is. If you are looking at cooking pizzas one day and maybe a roast or so the next day then a thermal break(s) may not be needed. If you after several days worth of cooking then maybe a thermal break(s) is worth investigating. Not to hard to work into your design.

[danjmath]

I've found the IFA playsand has been the best by far for making mortar. No need to screen it, which is more than I can say for any other I have bought.

I just finished the third course last night, and hope to get through the 5th by Saturday. Now that I have gotten the hang of the dome, I have started to worry about the chimney.
I am already over budget on this project, so looking to get it as cheaply as possible, without adding too much work, and open to suggestions.

[danjmath]

I just got the course above my entry arch finished, but I screwed up on the angles. It was dark and I I was in too much of a hurry, and just eye-balled the bricks over it. Now the diameter of my "circle" is 18" by 19". Any advice on how to fix this? It is above the arch, so it would not be too visible. I thought I could just do a quarter-thick brick course to get it to the proper size, but I am not sure if that would be the best approach.

[thevance53@gmail.com]

I am not the most experienced builder, but I would probably try and make it back up in the next three or four courses. If you don't, it will likey compound the issue. You won't see it above the entry arch, but you don't want a really big mortar joint or it will most likely crack.

[danjmath]

Well, finished my Dome just in time. I'm out of town for work all this week.
I borrowed a halogen light to start the curing process. Would it be a good idea to have my wife turn it on a few hours each day while I'm gone, or since I'm still going to put down insulation and a pcrete layer would that be a waste?

[thevance53@gmail.com]

Way to go Dan. I wasn't so sure you would make it before Winter. You still have a big push with the Entry Arch, insulation, and p-crete, but keep rolling. I used a light for quite a while when I couldn't keep curing fires going during the week. I don't think it hurts anything, so keep it on, it will really help when it starts getting cold. I used a thick visquine plastic that worked much better than a blue tarp to keep the moisture out.

[danjmath]

Does the Entry arch need to be insulated and/or weatherproofed-protected.
I like the look of the firebricks I'm using, so I had originally planned leaving the entry arch unadorned fire brick, but I live in an area with pretty harsh weather and snow, and now that I think about it I'm worried about ruining the CaSi board under the front landing, plus I don't know the shelf-life of unprotected firebrick and homebrew.

Also, does adding more thermal mass to the vent arch make much of a difference in heat retention, or reduce the amount of wood needed?

[JRPizza]

I didn't insulate my entry arch and also liked the look of the firebrick so have for now left it exposed. The firebricks do really hold water/moisture and I would not consider leaving them exposed where they could get directly rained/snowed on. Mine suck up enough moisture just from humidity but that does not seem to be a problem at this time. Are you planning a roof or enclosure for your oven? Once you dry your oven out you really want to keep water out of your insulation and anything porous, as you will have drive it all back out with heat, and if it freezes you can have expansion damage like Gastagg did.

[deejayoh]

Agree with JR. you can't leave the firebrick out in the weather. Really, any masonry or tile covering on an oven is going to absorb and wick water. There may be some modern polymer-based stuccos that can stand up to the elements, but generally I think it not a great idea to have exposed masonry in an areas with a lot of rain or freeze thaw cycles. You will end up with water in the oven.

Adding thermal mass to the arch probably won't affect your wood needs that much, but it affect heat retention by sucking heat out of your dome. More mass with less insulation. That's the theory behind the heat breaks - to add a layer of air between the dome and the arch.

[danjmath]

Thanks for the input. I guess I probably will insulate the entrance, since I am doing the dome anyways, and I still will need to weather-proof it.
I plan on stucco-ing the dome, but I don't feel like doing that to the vent arch. Guess I'll look around the forums and see if anyone has done something interesting.