Structural Slab for new WFO

[mikku]

Re: Structural Slab for new WFO

Started cutting the thin stone with a diamond wheel on an angle grinder---less than satisfactory results.

But where the cuts were, they will not create any problems. But this was for the 30mm thick stuff only. Thicker stuff --even cutting both sides, still have to rely on breaking the stone...

"Ideas bouncing around inside my head again"..."this stuff is pretty soft!"

"Wonder if my siding saw--used for Hardee and other concrete board --world cut this stuff? Worst thing that could happen--destroy a $70 blade!

To my surprise, the saw performed great, dust collector kept my lungs clear, and got nice 90 deg cuts on slabs! --- and deeper cuts, left only 5mm uncut!

Now I am thinking of trying to make the joints partially disappear---maybe use yesterday mortar recipe, but substitute "micro sand" for the "sand" and make the joints maybe 1-2mm only! Once the mortar is in place, thinking about rubbing stone dust into the surface of the mortar??? Maybe it will "poof" disappear? Probably need to mask the surfaces either side of joint so excess mortar does not spread onto the face??

Then leave the assembled pieces set for a few days before tipping the arch into place as a unit? But, maybe trying to hide the joints may just draw attention to them?? Who knows? 50/50 toss-up! They will probably crack there in the future anyway!

(See what is happening now! I am argueing with myself! --dimensia!")

Do you think this will work? That is on the list of tomorrow "things to do".

My thought, thickness of joint maybe not important as long as it is proportional to size of aggregate!







On another note, used a diamond cup type cutter to level concrete on exterior landing, I think that thinset is now possible... However, there will be about a 5/8" step down from top of firebrick to top of "Oya stone"-- Maybe that is a good thing ---if eventually I make an exterior door on oven--used when firing to heat up... I will have a 40mm recess (surrounding the opening) created by the oya stone decorative arch.

As for the door, thinking that the very thin "Oya stone" could be sandwiched inside a door fabricated from .8 or 1mm mild steel, the stone would hold up to wire welding the sandwich together and provide some degree of heat retention in the oven opening! The thin stuff, sometimes broken pieces are very cheap and light!

[Laurentius]

Re: Structural Slab for new WFO

Hi Gary,

That's one good looking oven, now get it outside and finished.

[mikku]

Re: Structural Slab for new WFO

First came the Sun.... Then came the Wind....





and when the day was done...he said "It was good!"

Looks like it is starting to dry!

"See! Sometimes I do take advice !!!
Tomorrow more of the same!

[mikku]

Re: Structural Slab for new WFO

Remember that it is not temperature alone that determines how fast something will dry, but a combination of temperature humidity and air velocity (wind). If you can't get the thing outside to get the sun and wind do much of the work you may need to arrange a fan on the outer surface and vent the humidity outside. Where I live pottery usually dries much faster in the winter because although the temperature is lower we don't have the high humidity like we do in the summer even though the temperature is way hotter. You have three inches of refractory, another four of wet vermicrete and probably another one of stucco. With that little heater it will take a long time for any of it's heat to get anywhere near the outside.
After a couple of weeks of your drying throw some plastic sheeting over the dome to see if it still condenses under the plastic. This will tell you if there is still water present.

I realize that I am doing things differently from what is recommended.

It started raining last evening, and it has been raining all day. The outside temperature is around 8 deg C. Has been dismal, a steady sprinkling with no wind all day! I am assuming the outside humidity is extremely high, indoors my weather ball sits at 55%. Not a great day for drying clothes anywhere.

The little stove has the oven floor at less than 50C, the other parts of the dome are hotter to the touch. Probably neither will move much for a long time, but better than nothing. (If that is any consolidation?) Some drying is occurring by the slight exterior color change but must be considered surface drying only!
I am sure when I shut the heater off for the night, in the morning--the damp appearance will have returned.

Got news that my stainless- spiral pipe became a "special order", local supplier no stock--so next week at the earliest.

This afternoon, I had a chance to visit a quarry for "Oya stone". You can google the product and see its characteristics. The place I went is called "Yamaminami", translated to "south mountain". The manager I met a few years ago stops to visit at our house occassionally. He took over the quarry operations from his father and made some progressive changes. Most of the other quarries cut larger dimension stone pieces. He realized that the "higher quality" oya stone is becoming more difficult to locate, so he began cutting the stone into thinner sections, beginning with 15mm thickness and then modular sizes upward in thickness. His reasoning--to allow more people to be able to use the high quality stone--even if it is in veneer thicknesses!

He showed me some of the stone he had and suggested different grades for my outside landing and what will be my decorative arch. Landing will be 30mm thickness, and I need to cut pieces out of a 60mm thick slab to form segments for the arch.

He said that he would cut the required pieces I needed but convinced me that an angle grinder would do the same job, and I have a "diamond cup" that i can polish where I need to snap the stone.

He gave a brief history of mining in the past.. the workers would use a hook type instrument to groove blocks of stone, then use wedges and mallets to crack the blocks free.

So this will be my next undertaking while waiting for the chimney and weather to improve. I have free time now, so I need to get as much completed as possible--hard to believe it is already over a month into the build.

I really appreciate advice, words of wisdom and experience, raw facts and all the rest! I need to sort out which is best for me and take whatever comes of it.

Please keep the information coming--"the only one that I can blame for mistakes-- is me!" And not for lack of information!

You can always point a finger and say "Ore shiranzo", a local term for "don't blame me"! There is a good webpage on the "Oya Stone Museum", it opened after the mine closed and gives the public a chance to walk through these huge underground spaces!

[mikku]

Re: Structural Slab for new WFO

That laugh is devilish---
and the drying is slow,
AND I just lost a well thought out post! poof and it was gone!
must have been the laugh!

[Laurentius]

Re: Structural Slab for new WFO

hehehhehehhhehh, its Not! Hope everything is drying out.

[mikku]

Re: Structural Slab for new WFO

Mikku,

Prepare yourself for eternity, the only smell you will savory will be sulfur and brimstone.

That doesn't sound like any discription of "heaven" that I ever heard of!

[david s]

Re: Structural Slab for new WFO

Remember that it is not temperature alone that determines how fast something will dry, but a combination of temperature humidity and air velocity (wind). If you can't get the thing outside to get the sun and wind do much of the work you may need to arrange a fan on the outer surface and vent the humidity outside. Where I live pottery usually dries much faster in the winter because although the temperature is lower we don't have the high humidity like we do in the summer even though the temperature is way hotter. You have three inches of refractory, another four of wet vermicrete and probably another one of stucco. With that little heater it will take a long time for any of it's heat to get anywhere near the outside.
After a couple of weeks of your drying throw some plastic sheeting over the dome to see if it still condenses under the plastic. This will tell you if there is still water present.

[Laurentius]

Re: Structural Slab for new WFO

Mikku,

Prepare yourself for eternity, the only smell you will savory will be sulfur and brimstone.

[mikku]

Re: Structural Slab for new WFO

I am gambling that it will not in this situation. The combustion is taking place outside of the oven, vapors should be similar to other fossil fuel -- CO2, and H2O, burnt twice--get Carbon monoxide. Maybe some other hydrocarbons but I have never smelled prolonged fuel odors inside a house where these heaters have been used. Also, there is no smoke evident!

The only wolfing going to happen around here is when I finally get to "wolf" down a great piece of pizza! Hopefully in the next few weeks!

Thanks for the devil's advocacy position--I would hate to be smelling sulfur and brimstone!

[Gulf]

Re: Structural Slab for new WFO

I am just being the devils advocate on this. I'm not meaning to be "woolfish". Charcoal starter fluid can leave a residue in steel that lasts from cook to cook. Do you think that diesel or kerosene (starter fluid) could permeate porous masonry?

[mikku]

Re: Structural Slab for new WFO

After tossing around the drying, and firing methods; I came up with my solution based on what I have on hand.

A normal heating device used here is called a "fan heater". (FON-HEE-TAH in Japanese). It is fueled by a high grade of kerosene (supposed to not stink too much during use), but requires windows to be opened regularly to allow fresh air in... That has always been a counter-productive issue with me... but??? Old houses here do not need windows to be open--because there is plenty of fresh air leaking in everywhere and very little insulation.

The device has a thermostat for air temperature, and an automatic shut down program where it turns off every three hours.. if left unattended or as a reminder to allow fresh air in.

The blast of air that this little unit produces is pretty hot, but not nearly as hot as heat beads, I hope that it will eventually heat the refractory warm enough to start forcing the water out.

There are a couple of photos of the little heater, its performance data label and how it is set near the oven.

The thing consumes 1/3 liter kerosene per hour of operation. That is more than my total heating system uses to heat 1500sf on a daily basis. But my house is very well insulated--only using 5.5 liters/day last month.

I will run this for a few days to see how the drying goes. It will give me some time to get my chimney, arrange for a forklift and some other things for the following week. It will only heat the dome to the initial temperatures of firing--everything else will have to be done with an alternative fuel type.

I can tell right away--I have to keep some windows cracked all the time. Even though it is burning clean, it is dumping gasses in the air giving me a headache!

[mikku]

Re: Structural Slab for new WFO

It would be nice to have some warm sunny days.. those are just weeks away before spring sets in.. probably the best time of year, things start sprouting, cherry trees come into bloom and still several months from the rainy season that seems to never stop...June thru Late July sometimes daily rain...Then the skies clear and suffocating heat and humidity! So humid that your sweat does not want to evaporate at all...just soak in it! High temperatures and dry weather are easier to tolerate...sweating has a cooling affect.

The lazy days of summer are still far away.. just looking forward to not having to burn wood in the wood stove upstairs--but instead in a newly commissioned WFO consuming my hoard of dry oak!

Best thing about right now...no insects!

[mikku]

Re: Structural Slab for new WFO

Pictures, we need pictures.

Just getting back to you!

[brickie in oz]

Re: Structural Slab for new WFO

Today was the first day that the sun shone with any intensity and the temperatures were higher.

Ill send you some we have plenty, we have it laying all over the ground doing nothing all I have to do is scoop it up in a bucket.