Oven Build in SC

[stonecutter]

Re: Oven Build in SC

8-10:1 would be what I would do if it was mine. Dry time is going to vary depending on your water content, humidity in the air, etc etc.

[videts38]

Re: Oven Build in SC

The dome itself has been completed since November, and unfortunately since then I was only able to finish the entrance and chimney area due to the cold and rain of winter
So it's had a significant time to dry on its own. I am putting the 3" ceramic blanket that is recommended and for added measure I am putting ~2-3" of vermiculite/Portland cement to help me maintain the igloo shape then the waterproof stucco.
I will still be curing according to the recommended procedure of 200,300,400,500,600,700,800 deg F/ at increments of 100deg. a day.

I'm not sure of the ratio of vermiculite/Portland cement for the outer insulation though. Then how long would I need to wait before sealing it with the waterproof stucco?
Anybody know these answers?

Thanks for any input.

[cobblerdave]

Re: Oven Build in SC

G'day
I look at drying and heat tempering the oven as separate if you can. Dry the dome out first . Dry with no flames,bare dome, no insulation. A 150 watt bulb then an old baking dish of burning charcoal. Sun and wind on the outside. Tease the water out not turn it to steam.
Then when its as dry as it can be, put on your insulation, then you can introduce some flame and those higher tempering temperatures. Putting a wet layer of pearlite cement over will just wet everything again. If you using dry insulation keep it dry. If your using pearlite/cement just use pearlite/cement and be prepared to let the sun and wind dry it over many weeks. If you building an igloo is easier to render straight onto ceramic insulation than it is to apply pearlite cement layer.
Anyway that my take on that
Regards dave

[mirassou]

Re: Oven Build in SC

Are you going to do an enclosure? If you are and from previous answers to questions that I posed, you really don't need the vermicrete layer but can do it if you want. Like Laurentius stated, I secured the blanket and then starting slowly firing. Utahbeehiver's comment also makes sense, but I didn't want to have to fool around with the blanket more than once. After most of the curing fires, I secured it and started working on the framing for the enclosure. Once I had the walls up and part of the roofing, I filled the interior with vermiculite.

[Laurentius]

Re: Oven Build in SC

You can start curing before adding CF blanket, that will allow more moisture to escape faster.

[UtahBeehiver]

Re: Oven Build in SC

IMHO, If you are going to do a final attachment later, then you can just lay a CF blanket over the oven to reduce thermal shock but your curing fires really start out slow anyway and you should not ramp the temperature up too quickly. Take the slow road and be patient. This is the time we see a lot of builders hurry too fast. You can still cook some meals during the curing process. Just don't let the CF get wet from any rain.

[videts38]

Re: Oven Build in SC

A question if anyone can help.
I'm putting on the ceramic insulation blanket this weekend so I can start the curing fires!!!!(Yeah I'm excited)
My question is; do I permanently attach the blanket then start the fires or do I just kind of lay it over the dome loosely? I wasn't sure if I would be driving moisture out of the firebrick only to be reabsorbed afterword during the cooling of the oven.
I will be wiring the blanket over the dome permanently to keep it in place before I apply a layer of vermiculite/Portland cement.
Which brings me to my second question; Is there an ideal ration of vermiculte/portland cement that I will be using over the insulation blanket?
Anyone with any thoughts about this?
I appreciate any and all thoughts concerning this step.

Steven

[mirassou]

Re: Oven Build in SC

Looks great! Congratulations!

[videts38]

Re: Oven Build in SC

Well I've determined I'm not a mason. I finished the front face of the oven. For me it was a little tougher than the oven work. I think I had mixed the the mortar a little loose. I could have gone with a stiffer mortar and it would not have been as messy- I think. Oh well, I'm glad it's done, now on to the ceramic blanklet then the curing!!!
Also the picture attached are scrap pieces that I mortared together during the build, just to see how each batch of home brew worked for me. The good news is I can't break any of them apart so at least I get a warm and fuzzy about that!!

[UtahBeehiver]

Re: Oven Build in SC

Try some muratic acid available at any big box store, use the right PPE. BTW oven is coming along nicely.

[videts38]

Re: Oven Build in SC

Thanks Mirassou

Gulf, you are right. I didn't know there was a wait time to clean mortar. This oven is the first time I ever tried to mortar anything. I will try to wait some time before I "tool" the joints. I also have a tendency to put too much mortar in the joints then tried to clean right away.

[mirassou]

Re: Oven Build in SC

Very nice!

[Gulf]

Re: Oven Build in SC

More Progress.

Also, started the brick facade for the front arch. But before I get to far I have a question if somebody can answer.
I'm using old bricks that kinda have a craggly surface. I can't seem to get the mortar all cleaned off like I could on the fire bricks. I've tried to brush it off but when they dried they still had a mortar film over them. Is ther a way to get this off so I will have the nice red brick face to it?
Thanks for any help.

Steven

Steven,
It looks to me like you may not be waiting long enough before you begin tooling the joints. Using the right consistency mortar and learning to judge how much you need takes time to learn. The best way to keep them clean, is to not get the mortar on there to begin with. But, if you wait long enough to begin tooling those joints, you wont smear it further on to the brick. And, what was there will have less tendency to stick to the face .

[videts38]

Re: Oven Build in SC

Another picture

[videts38]

Re: Oven Build in SC

More Progress.

Also, started the brick facade for the front arch. But before I get to far I have a question if somebody can answer.
I'm using old bricks that kinda have a craggly surface. I can't seem to get the mortar all cleaned off like I could on the fire bricks. I've tried to brush it off but when they dried they still had a mortar film over them. Is ther a way to get this off so I will have the nice red brick face to it?
Thanks for any help.

Steven