Planning a 42" oven build

[Jmh8098]

Hello all, my name is Jason and I am in the planning phase for a 42" oven build once the ground unthaws here in upstate New York. I am a competent carpenter, though I don't consider myself a mason, I have done quite a bit of masonry work. I downloaded the plans as a guide, which I plan on sticking fairly close to. Just have a few questions. The plans don't mention footings below the frost line. I would think I would need these here in NY, am I correct? The rest of the build is in my skill range except for choice of the appropriate refractory materials, specifically mortar. I found a castable firebrick cement made by A.W. Perkins that says it is rated to 2,200 degrees 100$ for 50 lbs. would this make for a suitable mortar for layup of my firebrick? I would think it would tolerate the wide gaps between the brick on the outside well. My other question is about setting up my trammel. What height do I set my pivot point at to get a true prabolic dome? I'm thinking it would be level with the tops of my soldiers, am I correct here? Lastly I would like to incorporate some type of thermometer probe for internal temperature that I would like to be able to read on the outside. Has anyone done this? That is all I have for now.

Thanks!
Jason

[RandyJ]

The prevailing though is that if you need footings in your area then that is what you should do. But that topic always brings up a lot of controversy. I live in MN and I did not do footings and so far have seen no frost heave. On the other hand my brother in law had a new apron poored this fall and it heaved 2" by x-mas, so I think a lot has to do with soil type. If you have a lot of clay you better do footings.

As for the mortar I would recommend the home brew. It works great and is cheap. It is 3,1,1,1 sand ,hyd lime,fire clay and portland cement.

For the dome gage you want the base as low as possible. That way it will be round.

Randy

[Gulf]

Jason,

Welcome to the forum ! I agree with Randy on the "home brew". Don't waste your money on the refractory mortar. Also, the height of the pivot for the Indispensable Tool. ( I had to google "trammel" ) You can get the same height, and a stronger dome if you use half brick stretchers rather than soldiers for the first few courses. I really don't think that a soldier course is necessary for the larger ovens. Building the dome as a true hemisphere will make it even stronger with no need to buttress. I live too far south to have an opinion on frost lines. And, yes, there are plenty of builds on this forum that have included temperature probes in their builds. Here is a "quick search" of the site for temperature probes.

I hope this helps!

[RandyJ]

Thanks gulf. I made my IT tool from a castor, turnbuckle 5\16 threaded rod, and a 4 hole 90 degree strut L bracket that I drilled and taped on the brick center line. Also all the mortar you will need can be made for 50 to 75 dollars compared to 500$. Plus you don't have to worry about it shrinking and cracking

Another option for the first row is half height soldier course. I did this and cut the angle for the first row in to the bricks. It worked out pretty good and was easy to do. I also don't have any of the temp sensors. I thought about it but cut it from the list due to time constraints.

One last thing I want to say is to insulate as much as you can afford. It does pay off with better heat retention and heat up. Also do the heat breaks at the vent and landing they are very important.

Randy