Structural Slab for new WFO

[mikku]

Re: Structural Slab for new WFO

Wow! where does the time go?

Most of my roof is in place but the biggest hang up is the roof flashing for the chimney stack. Been trying to save some money in doing the work myself -- again. Fireworks stove shop wanted over $200 for a roof flashing, so did some web surfing how to fabricate a cone from sheet metal with a roof slope; tried the graphic layout first on plain sheet metal, then transferred pattern to .3mm stainless. Then had to try soldering stainless.

My joints came out OK, but having clean metal I guess is the trick. Washed everything with soap, then acetone, then flux and finally soldered. The stainless really heats quickly so you have to be very watchful and do a little at a time. But do able! The seams "are not perfect" but they hold together. Will seal one more time with paintable silicone, then spray the transition black with high temperature stove paint.

The silicone should be far enough from the stack not go be combustible--I hope.
Really slow going! Slower today because of snow!

[mikku]

Re: Structural Slab for new WFO

No more bending over to cook pizzas, enclosure is looking very nice and precise as usual will all of your fabrication processes.

Happy New Years' Greetings-
Right now, without the ground slab in place, it is too high for easy access.
Once the concrete slab is done, it will be fine for me, but my wife will need a booster bench. Otherwise it is OK. No possibility of lowering it now.. just don't have to equipment necessary and won't borrow any again!

When the enclosure is finished, pizza making will be like the old saying for the USPS--concerning bad weather deliveries! Don't know current motto of Post Office.

[UtahBeehiver]

Re: Structural Slab for new WFO

No more bending over to cook pizzas, enclosure is looking very nice and precise as usual will all of your fabrication processes.

[mikku]

Re: Structural Slab for new WFO

Got the oven outdoors over the last few days. Now a lot of work to get everything wrapped up and finished. That should take 2014, but will be able to use the oven much earlier under any weather condition.








Oven is supported by 3- 180x105 Douglas fir beams (free span 2185 mm), this gives an open area under the entire oven. And now the entire oven can be insulated again.

[mikku]

Re: Structural Slab for new WFO

The engine rebuilding was not for me--I like to tinker with things as you might figure out by now, it was for a friend's backhoe, a small diesel.

The splitter design is still something in the future. The hunting and gathering of components is ongoing. The cylinder and pump are still not available because the dozer/loader has not been recycled yet--I am on the want list for parts. The engine would be from a Japanese K-truck. Vehicles here with the K identification have engines not to exceed 650cc. There are a lot of engines around, probably easiest to find a vehicle then take what you need and send the rest to the metal recycler. There is not an abundance of splitters here but one of the few around belongs to a friend of mine. I usually will borrow something once--after--I usually get or make my own. The reasoning behind that is--if something breaks it is my responsibility anyway. So far, the recoil start mechanism broke on the first pull; $100 for the part and a 3 week wait. Also, the cylinder guide that rides below the "I" beam (made from brass) has deformed from my usage over several days. I will need to have a machine shop mill a couple of new guides before I can return the splitter to my friend. I guess the repair parts would add up to what a rental shop might charge--if splitters were available for rental.

The concrete work did end up being a pretty hard project. Used almost 4 tons each of sand and 1" crushed rock. The design and need for a retainer wall developed as I worked with the variation of land levels. When I have free time, I just like keeping busy no matter how difficult the project might be.

I saw your deck and pergola project. You like difficult jobs as well. Do you have any detailed photos of the fancy joints on the roof structure? Most people at first glance do not appreciate the work going into it. I am sure it provided a great amount of pleasure for you. I can see from all your previous work that (half-assed work) is not in your vocabulary--only top quality or nothing! I wish you would have included outdoor shelter for your oven. But that is only my idea for year around use.

Our temperatures are sometimes below freezing overnight and chilly but nothing like what has been hitting the USA recently. I am glad to not be living in Northern Minnesota right now. Areas around where I lived had 2 to 3 feet of snow and deep freezer cold temps!

I imagine you are gearing up for skiing season. Be careful and enjoy.

[UtahBeehiver]

Re: Structural Slab for new WFO

Mikku,

That is a serious amount of wood. You foundation look very good especially with a hand mix/pour. It is cold here, 9-10 degree F in the morning with a high of mid 20s. Nice to have a neighbor with a splitter. Were you not looking a building one from an engine you were rebuilding?

[mikku]

Re: Structural Slab for new WFO







I disassembled the previous woodshed, did ground preparations, formed and poured the concrete for woodshed and oven location---now the concrete is curing so time to hit the wood pile hard and see if I can cut and split all before work calls me back to being busy. Had to make a temporary structure to keep the newly split wood undercover until it can be loaded into the new woodshed. That is still some time off!

The concrete took a bit of wind out of my sails. Mixed it all by hand, but surprisingly it came out better than I expected. All the walls are 150mm thick with reinforcing steel (welded together)--I am lousy with tie wire!

Maybe a home for the oven soon? When who knows?

I am sure lucky to be able to use my friend's wood splitter. It sure can bust apart some mean pieces of oak--even chunks where the tree wyes or large branches begin. Just tears right through them without even a cough!

[mikku]

Re: Structural Slab for new WFO

Been very busy for the last few months. All the work involves driving for 1 1/2 hrs each way...so makes for a longer day.

The oven is now back indoors sitting on casters.

I decided to make a new wood storage structure, a little larger and have space for the oven near the house. But this involves removing 2 years supply of dry firewood, and disassembling my current wood shed. Forgot to mention, making the building larger means removing the remains of a huge oak tree. The stump is almost 4' across at ground level.

Lots of fun and games, dig up the stump and roots--but now have to recycle the remains! Pressure wash it and try to cut it up into usable sizes! That is a project for early spring. Now it is ground preparation, foundations, retainer walls, a little plumbing and building a new structure. Hopefully, by year's end, the oven will be up and running on its own base---under cover! High hopes! Maybe another week off will get me jump started enough to get the project done on my schedule.

[mikku]

Re: Structural Slab for new WFO

No.

You have had all the good responses you are ever going to get, you need to pick one that suits.

None really suit--so I guess that is the end of it. Have to play on my own!

[brickie in oz]

Re: Structural Slab for new WFO

Now that you have had your chuckle, do you want to comment on the insulation question?

No.

You have had all the good responses you are ever going to get, you need to pick one that suits.

[mikku]

Re: Structural Slab for new WFO

No need to fight over me boys, there is enough to go around for everyone...........Ill make sure I bring some lube........

See! Almost like predicted!
Brickie in oz, you are a funny guy and really quick with your fun responses.

Now that you have had your chuckle, do you want to comment on the insulation question?

On other threads, you have given some real straight answers and they seemed to be broadly appreciated. So what do you think?

All the other big number guys have told me to follow normal protocol, like it is burnt in stone handed down from our heavenly Father above! I'm thinking it makes no difference at all and it might be an improvement---the pericrete layer would also be holding heat and not just insulating.

[mikku]

Re: Structural Slab for new WFO

Hi Mikku,

I think you misread the tone of my last post. I was certainly not acrimonious, I'm sorry if you read it that way, just trying to point out the facts. Your comment did not get under my skin. The reason I advised application of vermicete/perlcrete in 1" layers with a week of drying between each, is because that's the best way I've found to dry the stuff out. It's a bit like leaving a pile of sand in the sun. The top layer may dry, but underneath it will be wet for months. Driving the water out by fire, with a wet layer against the refractory can lead to rapid steam production which will swell and crack the vermicrete layer.This can occur well before there is any visible steam.
I have used ceramic blanket, but there are a number of reasons I prefer not to use it. One of those is safety, the stuff has produced tumours in rats, but to date there are no recorded human cases of cancers linked to CF. It is however banned for sale in Germany and we can't use it in schools here because children are considered more susceptible. It is still a superior quality insulator than either vermiculite or perlite. individuals can make up their own minds whether to use it or not.

I have heard those statements before as well as someone worrying about if the ceramic fiber was close to the dome and a crack would occur, the fiber might enter into the area where food is being prepared--another statement I heard that possibly ingestion is not a problem but inhalation is.

The scenario I stated keeps the fiber away from the dome itself--almost no chance of any fiber ever entering the burn chamber.

So with all those things to consider, why would you recommend using the stuff at all?

Big circular conversation really going nowhere..

But again, thank you for your response. I will certainly keep it in mind when I decide if I am going to make any changes at all!

[mikku]

Re: Structural Slab for new WFO

Maybe my answer was "out of character" because the cracks in your vermicrete layer occurred because you did not take my advice about drying it.If you had followed my advice you would not be in the situation you are in presently.

One reason the blanket is better placed against the refractory is that you are preventing the heat entering the vermicrete layer.With the blanket on the outside you are storing more heat in the vermicrete layer. Another reason is that with vermicrete directly against the refractory, water that is stored in the vermicrete is far more easily turned to steam which,as you've found, can create problems.it is better and more efficient, but not mandatory, to place the better insulation closest to the heat source.

MrChips said he likes this statement! What is to like about it?
I am not in any situation at the time--by build is like davids builds--same type of assembly... I see it lacking insulation and was looking for advice.

The answer I received seems like opinion rather than fact--IMHO should have prefaced everything said.

[david s]

Re: Structural Slab for new WFO

I see that the "comment like Brickie" is getting under your skin.. it should not, his answers are based on working with products for a lifetime, yours may be from studying the products and testing different things and manufacturing ovens.

But now you are talking out of both sides of your mouth at the same time!

I remember you telling me to take it slow with the application of the pericrete coats, and doing it in 1" layers. That part I did not take your advice--sometimes I use my own instinct... I do not think it created a problem except that it took much longer to dry.

I tried various ways of drying but in the long term, it was just time and firing of the oven.

You always had an opinion that ceramic fiber is a dangerous product, now you are hailing it as a superior product. What will you be advising tomorrow?

On most of the other things I have taken your advice over others and it has turned out fine.

As far as creating steam, no place or no time during my construction has steam created a problem or caused excessive cracking, Spaulding, explosions or anything. It is just a normal phase that water goes through in the drying process.

A lot of whoopla was made about the importance of slow curing for the refractory and I really wonder if that is all so important either. In commercial applications where refractory cements must be used on furnace repairs, they do not phase the temperatures up as everyone suggests. They have a kiln down for repairs and it is costing them money for the repairs and down time--when the repairs are completed, they want these machines on line as quickly as possible. And the temperatures that they are designed for are much higher than a WFO. Probably all the advice given on the forum is to be on the extremely safe side. I think the advice would be more important where quality of the build is concerned.

I mentioned cracking on my pericrete layer, but that is not the reason for considering installation of a ceramic blanket. I could add another 8" of pericrete and do the same thing for 1/10th the price. I just don't want to wait for the stuff to dry out like before. I will probably never use the stuff again because of the time lag--nothing else.

I wish you would "point fingers" when other people do not follow your advice.
This is also a first--as I have seen... out of character. I'm not Brickie, so you do not have to vent your frustrations because of some long standing feud or misunderstanding.

But thanks for all the information you have provided in the past.

It is like when people find themselves with little to do, they begin to infight among themselves. Usually I agree with your ideas... this time not so much!

Hi Mikku,

I think you misread the tone of my last post. I was certainly not acrimonious, I'm sorry if you read it that way, just trying to point out the facts. Your comment did not get under my skin. The reason I advised application of vermicete/perlcrete in 1" layers with a week of drying between each, is because that's the best way I've found to dry the stuff out. It's a bit like leaving a pile of sand in the sun. The top layer may dry, but underneath it will be wet for months. Driving the water out by fire, with a wet layer against the refractory can lead to rapid steam production which will swell and crack the vermicrete layer.This can occur well before there is any visible steam.
I have used ceramic blanket, but there are a number of reasons I prefer not to use it. One of those is safety, the stuff has produced tumours in rats, but to date there are no recorded human cases of cancers linked to CF. It is however banned for sale in Germany and we can't use it in schools here because children are considered more susceptible. It is still a superior quality insulator than either vermiculite or perlite. individuals can make up their own minds whether to use it or not.

[brickie in oz]

Re: Structural Slab for new WFO

No need to fight over me boys, there is enough to go around for everyone...........Ill make sure I bring some lube........