Duane's 42" Build

[MarkJerling]

Feels great once you have the plug in right!
Well done.

[Hamilton]

Have made a little progress as of late.
Next up is to cast a cap for the chimney to secure the vent anchor and start insulating this thing.
I am considering using perlcrete around the perimeter about three inches deep and five and a half inches tall to give the insulation blanket something to set on and perhaps hold the brick floor in place and then do the layers of perlcrete over the both. Any thoughts? Can somebody refresh my memory on the perlcrete mixture? Would the perlcete be a suitable support for a granite landing?
Just figuring this out as I go due to a lack of planning. The chimney looks a little odd as I am trying to keep the mass as small as possible.
Appreciate any help I can get!

[MarkJerling]

You're a master mason! Beautifully done.

[Hamilton]

Hey guys,
Hope this post finds everybody well!
I have attached a couple of photos in hopes that some one may be able to tell why there is a difference. The photos show the difference between the perimeter of the two backsides of the suspended slab and what the other three look like. I like and would like to duplicate the wood grain texture as a veneer around a support for a quartzite piece I hope to purchase to form a landing. The other photo show more of the aggregate in the mix that I would like to avoid but I don't know why there is a difference. The suspended slab was formed with a 5000 series concrete from a company here in town that specializes in small batches
Any thoughts/ideas would be appreciated.

Thanks
Duane

[Gulf]

It looks like one side was poured wetter and/or vibrated. There also may have been a difference in the way the form released. A wet form board will not bond to the concrete as would a dry board. A good release agent will help transfer the graining you want. Otherwise, it may stick to the form when it is removed revealing more of the aggregate.

[Hamilton]

Thanks Joe.
I did rent and vibrate the concrete as we were bucketing it from the concrete buggy to the form.
I will do some research regarding release agents.

[Gulf]

A form board can also be removed too soon. I have done this purposely with no release agent when wanting an exposed aggregate finish. It will sometimes look similar to the rough pic that you posted.

[Hamilton]

I abandoned the concrete form for the supporting landing and went with a 3" wide and 5.5" tall support for the landing and around the perimeter of the oven. It is a 6 to 1 perlite and Portland cement mix. My hopes are to provide a bit of insulation around the perimeter as well as a backer of sorts for the floor bricks and fire clay and sand mixture between the castable and the floor bricks and to be a support for the quartzite landing and backer for the quartzite risers.

Some really weird stuff, I hope it works!

Attached is a few photos of todays progress. I mocked up the landing and the guy was able to sell me and will be cutting the piece of quartzite for the landing and the risers.

Any suggestions how to mortar or use an adhesive for the landing and risers to what I have done?

[Hamilton]

One more thing.

Look at all these excess cuts and "practice cuts".

[Hamilton]

Can anybody recommend a high temp adhesive/silicone to attach the chimney pipe anchor plate to the fire brick?

[Pizzarotic]

Any fireplace or flue supplier should have high temp product's. Most pure silicones are rated for 400-600⁰f but can handle a lot higher temps. Lavalock have a 1000⁰ tape and Vitcas do a 1800⁰ sealant.

[david s]

The highest rated silicone I could find is Permatex Ultra Copper, which I use in my builds. It is ok provided flames are not allowed up the flue pipe. After about ten years use the stuff remained intact and elastic until my wife killed it when firing up the oven and allowing flames into the flue pipe. It killed the silicon, so I had to redo it. No big dramas, but I sacked her from firing the oven.
There are other non silicone solutions, but all that I tried went hard and didn’t remain elastic meaning they didn’t seal against material that is expanding and contracting frequently.
If using it under an anchor plate I think that will be too hot for silicone. The seal on my build is quite a bit higher up and therefore cooler. In that position it wouldn’t matter if it goes hard because it will presumably be covered in insulation.

[Hamilton]

Hey guys, hope everybody is doing well!

I haven't had much time to spend with the oven lately.
Doing what I can in these couple of days off.
Attached are a few photos of the latest progress.
Ready for the insulation and render know I believe.
I will be cooking out of this oven before the end of the year.

[UtahBeehiver]

It is really a shame that all the pretty dome brick work will be covered by insulation. You are on the home stretch.

[Hamilton]

It is a shame!