Structural Slab for new WFO

[mikku]

Re: Structural Slab for new WFO

Thank you! Compliments are always appreciated!
This entire exercise is to see what is possible, sturdy forms can be modified easier than starting from scratch again. So if this one doesn't work out, I can try again.
My wife makes great pizza now and is equally talented in bread making and regular baking. I have high hopes for the completed oven. The neighbors are waiting as well-- She bakes as a hobby so the kids and adults around here get a lot of her bakery product. They in return drop things off, fruit, veggies, eggs, fresh fish, etc ... You know when someone you haven't talked to in a while stops by with a gift of fresh fruit--that it is time for her to start baking again!

[mikku]

Re: Structural Slab for new WFO

As far as reusability goes, if my completed oven created some demand for my work, I could possibly get 5 or more castings from these molds. The basic shapes after that could be the starting point for making a proper more permanent mold from fiberglas or steel.

If you have made molds from fiberglas, then I am assuming you are getting a decent amount of work that justifies the expense.

Right now, I am assuming that there is no demand--even within the expat community, those who would have interest in WFO's are long term residents who would probably do their own builds just for the pleasure of a DIY completion.

Regular Japanese families do not have ovens in their homes, except for a toaster type or a convection microwave. If they choose to make bread, there are many electric bread machines around.

Our home has a full size gas oven/range 30" that I had to purchase through a dealer in Japan. The same product is available in USA for a fraction of the price but the special electric parts for 50Hz cannot be purchased outside of Japan--dealership issue!

Did someone say ? "You have to shake the tree to see what kind nuts fall from it".. If nobody wants to claim the quote--I will! So far, no potential customer nuts--but a lot of people interested in the diverse things I do.

A lot of people think I am the only nut!
Making a multi-ton, concrete monstrosity inside a garage! For making an occasional pizza! Maybe I am--but internationally, I think I am in good company!

[brickie in oz]

Re: Structural Slab for new WFO

The same product is available in USA for a fraction of the price but the special electric parts for 50Hz cannot be purchased outside of Japan--dealership issue!

The Hz difference shouldnt make a difference in a heating coil, the trouble starts with motors, but that too can be got around.

Motors turn slower/quicker with changing Hz, heating coils are hardly effected.

Some years ago I bought a spiderweb gun that makes webs from heat gun glue, there is a heating element and an air blower attachment, the heating element was made for the US at 110v 60Hz, we use 220v at 50Hz.
I adjusted the US plug prongs with pliers and plugged it in, all worked just fine.

Dont try this at home unless you are a trained idiot......

[mikku]

Re: Structural Slab for new WFO

I searched through casting photos, these give a pretty clear idea of the cast parts:











Description:
-first transition casting
-another view of transition
-front 1/2 dome section, showing oven entrance
-another view
-inside landing --transition to chimney.

These are in response to : We need pictures!

[mikku]

Re: Structural Slab for new WFO

120v/60hz vs 100v/50hz!

Crazy power grid in Japan! From Mt. Fuji to the east is 50HZ/to the west is 60HZ!

Most things USA made or manufactured elsewhere- power tools etc work just fine either place! Saws just run faster in USA. I purchase circulating pumps for use in hot water heated floor applications from there just because of cost savings! Huge like 1/10th initially, approx 1/4th after clearing customs etc! Have to look at pumping capacity, head, etc but otherwise just fine!

Trouble with LP gas range- slight difference in gas and amount of methane, this can be solved by re-jetting and air shutter adjustment.

Other problem is electronics for clock- digital OK, analog different story runs off current cycle. Or vice versa but clocks run slower/ same with oven timer. It is something you can deal with but for a proper fix, need the right part and only through authorized dealer here!

Lastly, issue with solenoid in gas valve. 100V not enough to energize valve to open properly. A fix for that is a booster transformer.. or the right part again!

Crazy short story: When I came here the first time a while back, I brought our range from USA along with household stuff, finally got the gas man to hook it up and the cook top worked fine. My wife wanted to try some baking while I was gone at work... That evening, she complained that it was taking a long time to make cookies (a real long time!!!!). When I finally got a day off, I checked things out when she did her next batch. The gas valve never did open the previous time she did cookies. The only thing that heated the oven was the pilot light. I think that the starting sequence allowed enough gas to flow to start the pilot--but there is something in the circuit that measures voltage or resistance or something through the flame and it was not enough to open the main gas valve! We were really happy to find a booster transformer to make the stove work...and so were the neighbors !! fresh cookies, cakes, pies, bread etc etc!

[mikku]

Re: Structural Slab for new WFO

Last casting photos:









There is a definite difference in the finish of the casting between inside and outside, all molds were cast filling from the top. The air/water migrated upward when vibrated--leaving the somewhat course texture on the outside. The inside finish is glass smooth (or as smooth as the mold).

[mikku]

Re: Structural Slab for new WFO

The insulative layer seems to have set up hard and flat.
The last batch I mixed, there was about a scoop full left over- so I put it into a plastic bag to retain moisture (as a sample).

That also set hard, but it will crack if you apply a significant amount of hand pressure and if you persist in working it-- you can make it crumble.

I don't think it will pose a problem - the structural slab (is) a permanent form.

Just wondering if that is the nature of the beast? Or a problem with the amount of water in the original mix?

The insulation layer has been covered with plastic for many days now and still there is moisture on the underside of the plastic facing the insulation.

[UtahBeehiver]

Re: Structural Slab for new WFO

Mikku,

I am very impressed with the quality work of your casting. I had a chance to visit your country earlier this year and found your country very inviting, friendly people, and would not hestitate to revisit. Keep sending pictures of your progress. Will be watching with interest.

[mikku]

Re: Structural Slab for new WFO

I thought you are located in Utah?

My country is: North Country wilderness, near "Boundary waters Canoe Area, Superior National Forest- Minnesota, USA!

Also a beautiful place!! Wonderful lakes, rivers, pines, good fishing, lots of white tailed deer!

I live in Japan for a lot of reasons, but still a Yank from Scandanavian stock.

Thanks for compliments.

Yes, there are a lot of friendly people here. No fear taking a walk anywhere at night!

Lots of heritage, nearby snow topped mountains, good water from mountain springs, tall trees, few people - at least in this area!

But little wildlife AND cannot eat the mushrooms for a while! --(maybe another 30 years). You know the "Cesium story"!

[mikku]

Re: Structural Slab for new WFO

Russell, here are a few more pics.





I laid the hearth bricks out on a table, first for marking for cuts.

Then looked at the scale of this oven.. it is only 29 1/2" diameter (750mm).

I don't think I can reach inside to change bricks if damaged!

My wife would not have the upper body strength to do it either in such a cramped position either!

So, I am going to pick up an additional 6 brick, fill in the perimeter with some 1/2 cuts and place the dome on top!

If there is a problem in the future--options:

-live with it
-cut some tiles to fit on top of hearth
-tear down and rebuild

Any are not that big a deal!

Now I am thinking of some type of light weight enclosure-but plans change (daily!!)

These brick are laid directly on top of the pericrete layer without anything below, used a level to check straightness; swapped out one center brick and no rocking or spaces beneath the level --all directions! Think I'm going to leave it alone before making it worse!

[UtahBeehiver]

Re: Structural Slab for new WFO

Yes I am a native Utahn but travel a fair amount. A long way from the Great Lake region. Can't recall where anyone has actually had to remove a hearth brick so I think you have the right idea of placing dome on brick. Good luck.

[mikku]

Re: Structural Slab for new WFO

If you are planning on coming this way again, you might enjoy some of the World Heritage sites around Nikko. It is about an hour by train (either JR) originating at Tokyo station or (Tobu Line) originating at Asakasa Station. If I have time, would gladly show you around!

Thanks-I am on my way to get the rest of the brick. Thinking now about using a very thin layer of plywood (1.5 to 2mm) to slide the castings over the brick. Then just leave it in place to burn away during the curing.

[UtahBeehiver]

Re: Structural Slab for new WFO

Use could use some wood dowels and roll the oven in place the remove them one at time. Kind of like how they moved the volcanic sculptures on Easter Island. Will have to check you area out. BTW those JR Bullet trains are an engineering marvel.

[mikku]

Re: Structural Slab for new WFO

Struck out on the brick, different manufacturers are different thickness.

The stuff I had ordered last week and received yesterday was supposed to be 65mm thick x 114 x 230, ended up being 61x111x128- Other place had a few brick but all 65. Ordered the (6) only as well as a "trowel on refractory" for closing the seams on the dome. But have to wait a few days. Patience is not one of my virtues. I really need to work on it.

The newest fast train is called "Nozomi" and that thing almost flies. That particular arrangement is for long routes heading out of Tokyo- to west Japan (Nagoya, Osaka, Hiroshima, Hakata in Kyushu). If you do come for any length of time, make sure you purchase a "JR Rail Pass" before leaving USA. It can be picked up here once you enter. A much cheaper way to get around for foreigners for limited time. (1 wk), (2 wk). Still a little expensive, but one quick round trip- Tokyo to Osaka would pay for the entire pass!

China has a new train that is significantly faster!

USA would be nice to have a system similar but the population is not dense enough to warrant the huge initial expenses--most places elevated over other roads and rail networks! Really an unbelievable undertaking, suited for Europe maybe USA --Florida to Boston corridore.

Have to try out the dowel system, sounds like a winner!

[Laurentius]

Re: Structural Slab for new WFO

Nice work, Mikku.