Wrong dimensions - Help!!

[peterthewolf]

Re: Wrong dimensions - Help!!

Hey everyone-

The mason has responded favorably on doing whatever we ask to fix the oven. He will be here early this Tuesday morning. If any of you have or might take a couple of example photos that show the low pitch of your own oven, this would be very helpful to us. Best is to just send them to my email which is:

pwolf1@wolfskills.com

Again, to all of you, it's been an extraordinary investment of time and energy you have put in to help us with this. We are so appreciative.

A final note, it just occurred to us, why not simply knock off the portion in question of the dome (like opening the top of a soft boiled egg), and both have room to get a hammer in there to blast the floor more effectively, and also simply rebuild it over a raised platform with styrofoam carved new dome interior mold. Re-vermiculite after the brick work, then re-rock the outside. It is all gone from front view and we get to keep the beauty. Hey, what do you think?

[peterthewolf]

Re: Wrong dimensions - Help!!

Brickie-
No, the wood was well seasoned. Also behaved fine while on the oven floor waiting to throw onto the fire. It's all about the mystery problem between the floor and dome. Just not an effective burn in there. You got to see another indicator (looks like too fuel rich) that we can't hit high heat inside very well, only temporarily when at all with half a forest going through it. There (is) burn; we've run a ton of wood through it and it eats up the wood just fine, but it generates a very thick smoke layer.

Guys, how about those thoughts on using the donut *instead* of having to chip into the wall. Can't we be ok with that donut support right *to* the wall???

[brickie in oz]

Re: Wrong dimensions - Help!!

Looking at pic 1 Id say your fire wood is still green as there way is too much tar and creosote on the door.

[brickie in oz]

Re: Wrong dimensions - Help!!

Petes Pics.

1. Looking in door frame. Door 15", flue in arch 18", dome top past flue arch peaks at 30"


2. Same photo with my hand. Flue hole is a hand's length up inside door, and there is that much distance again for smoke to travel out across arch before it reaches the hole and goes up. Remember, closing the flue from above can eliminate flow up this hole effectively removing it. But then this arch is 18", not 15". I don't see much difference in that (if) the flue is closed, but what about if open - what do you all think about this part?


3. Flue hole (slighly dark) in foreground, the deeper part of it's arch just in past the flue, and beyond, the peak of the dome.

[peterthewolf]

Re: Wrong dimensions - Help!!

Lburou-

That would be great! Thanks, and I'll call you this evening when I get home. I'd like to learn how to do this. Meanwhile I did already send Brickie the pictures before getting your message; he's been pretty quick (thanks Brickie) and they may be up by the time I get home but I'd love to learn how to do this.

I have three shots. Looking a little upward from just outside the door showing door frame, then flue hole in it's arch, then just passing the flue to see the dome. In one of them, my hand is in it so y'all get perspective.

One thing I wonder is about erosion. How can we be assured that silt won't creep in and someday fill up the airspace? - ok I think I have it - use a little mortar as "caulk" on the bottom of the support donut where it sits on the slab.

[Tenorio74]

Re: Wrong dimensions - Help!!

So Tenorio back to your drawing just to make sure I've got it. Sorry, let me ask again: It looks like your carved slot for new floor anchoring is the anchor point to prevent the floor from sagging down and breaking. But wouldn't the metal ring snuggled against the inside surface of the wall provide exactly that support? It would have to be 2 inches high, sitting on the original slab for the airspace. This is redundant, sorry, just want to make sure. Think like a wagon wheel's metal rim sitting in there. Wouldn't *that* support rim suffice for edge support of the fiberboard, instead of having to notch into the brick wall in a circle? This is the remaining part I don't understand - it would provide vertical support, but against the (not notched) brick walls, there would be nowhere the new floor could slide or move to, to break off or fall in.

Hi Peter, no problem with your question (this is theoretical work for me anyway, as I haven't done a mod like that myself).

Yes, the metal ring would provide the same support. Then again I was talking about a new slab. As you don't plan to pour one to end at the same height, you must however have solid, insulating, non-removable forms, as fiber board is NOT a load bearing structure. Just a outer ring won't do it. You need a sort of metal sheet floor I guess, something to support the weight of bricks and logs.

Your outer ring will have to go in in pieces though, as well as your forms....

[Lburou]

Re: Wrong dimensions - Help!!

You have a private message containing my phone number....I'll try to talk you through the process to upload pictures. Download a picture resizer first, then call me tonight and we'll get past that obstacle at least.

[peterthewolf]

Re: Wrong dimensions - Help!!

Tenorio & lwood-

It's been raining like crazy since I first took (not so good) pictures. I'm hoping to get some for you guys tomorrow during a lull in the rains. I will take stills, but in sequence going in the door, flue, then looking up at the dome. Brickie, at risk of bending you out of shape, I'll send them over, ok?

This all has given time for reflecting. First, I will be receiving the name from a good source tomorrow of a mason who can quote a demo and replace job on the floor (option 1). While we are at it, would it be of advantage to sit the new floor bricks narrow side up on their 2.5 inch sides, so the 2.5" long faces were up and down (or 5" height of floor brick) instead of flat? As in more floor to heat and hold heat than flat. Let me know, and of course that makes the floor 2.5 inches thicker therefore higher to put into the calculations. Just thought I'd ask. For those of you who suggested just demo'ing the whole oven and starting over, we believe that the ethical thing to do is give the mason the opportunity to do (our) research based orders: That is to give him the option of fixing (floor replacement, minimum), which no longer includes drilling a roof hole; only fixing the floor, possibly the dome, or doing the oven over. Know that considering the amount of money we have retained is the same amount at least, reasonably what he quoted it should take to build one in the first place, we have not ruled out demo. There is however, a LOT of material on the outside of this (very beautiful) structure, not just something like a coat of stucco. He'd likely balk and walk at the suggestion to demo, but that is his choice. As an old monk once said, "regardless of what is going on elsewhere, just keep sweeping your side of the street clean". We'll hold the option, without eagerness for the month it would take to demo, clean and start over; talk about a real mess.

So Tenorio back to your drawing just to make sure I've got it. Sorry, let me ask again: It looks like your carved slot for new floor anchoring is the anchor point to prevent the floor from sagging down and breaking. But wouldn't the metal ring snuggled against the inside surface of the wall provide exactly that support? It would have to be 2 inches high, sitting on the original slab for the airspace. This is redundant, sorry, just want to make sure. Think like a wagon wheel's metal rim sitting in there. Wouldn't *that* support rim suffice for edge support of the fiberboard, instead of having to notch into the brick wall in a circle? This is the remaining part I don't understand - it would provide vertical support, but against the (not notched) brick walls, there would be nowhere the new floor could slide or move to, to break off or fall in.

[Tenorio74]

Re: Wrong dimensions - Help!!

Peter,

If you take out 2.5" firebrick + 4" vermiculite = 6.5"

You would need to end at the same height:

2" metal support ring and metal forms (for airspace)
+ 2" ceramic fiber board
+ 2.5" firebrick
= 6.5"

Fiber board is not very rigid and can't be like a slab in itself, especially if (as I had to do) you put it through the door in door-size pieces.

After that you can figure out your lowering of the dome - but do bear in mind what I just realized - that your dome bricks WILL STILL suck up heat, through the wall. I don't know how much though. This could be a problem for slow roasts, because the heat will wander away to the colder bricks above the new lowered dome. Butit could be negligible... Just throwing out the thought.

[peterthewolf]

Re: Wrong dimensions - Help!!

lwood-

I'll go out within the next 2 hours and get the pics. But because I think context will be *much* better, I'll also take a 15 second video that can go into an email. lwood *and anyone else too*- if you'll send your email address to me at

pwolf1@wolfskills.com

then I'll send the video over to you. That way I can walk up to the door, move in and aim up so you can really see it. I'll put a light on, slide in and look up into the dome, so you can see it's height and shape at the same time. That way instead of the limit in pictures you can have immediate whole context.

Dome height: I was thinking this in reverse sequence of yours. The dome is (now) a constant up there at 30". I'm thinking, leave the dome up there until the all unknowns about the finished floor are gone (the floor is finished). Things can happen (Mr. Murphy showing up to change exact expected outcomes for final estimate finished floor height).

For the dome, *simple*. After the floor is finished, measure the projected final dome height. Cut the shelf to fit up there in the cone. Drill several holes into the brick and then same spots through the shelf. Stainless bolt it it up through several SS angle brackets (nice and thick-strong). Or just bolt into the dome brick and let bent angles of the brackets hold the shelf without drilling the shelf at all. Done. The only contingency is how big around to cut the shelf so that it's position fits up there as high as we want it. And before bolting - stuff some non toxic insulation up into the point of the dome behind it. Then as hot as the shelf gets and stays, great. If instead it mostly reflects heat, well it's doing that onto the floor and the surrounding walls are the generator for that. Once the shelf is bolted up there it is solid and strong. We could simply drill a hole down to it *then*, and pour either insulating castable kiln refractory into the void, cement and rock cap it off and forget about it. If instead of it being refractory, anyone thinks it's really better to have *even more* heat mass up behind the shelf, that's about a 5 gallon bucket's worth of space and it certainly could be heated - and hold heat. But that's more wood and heating time to attain which contradicts our purpose in the first place of making the oven more efficient.

Back to floor now: Follow me please - I am not an engineer. Blowing out the front of the oven is a mess. Too extensive and the expensive metal work goes with it. It also supports the arch area above. I wouldn't mess with that front at all. If we leave that alone, it means the new floor has to be the same height as the old one was. We have a 2 inch rebar-slab down there under the dome - on top of soggy ground. That stays. If we dig out vermiculite for the supporting donut circle down to the slab, we'll need four inches of support donut to replace the missing 4" vermiculite and be on solid slab for support. So it's a 4 inch support donut, not 2".

Dig out the 4 inch vermiculite all over, exposing the whole slab. Leave 2 inches of air. Suspend the two inches of fiberboard over the edge donut, (now 4 inches vermicuite is replaced exactly) and middle "X" supports like you drew, replace the half to one inch of mortar bed onto the top of the and replace the brick. Done. **Right???**

Then: Whatever level the floor really did finish at, it should be at least reasonably close to the original, so the door is ok and it is 15 inches.

Then if we bolt the shelf so it is 24 inches above the floor on it's underside, that's 62.5%.

How's that, have I done it?????

[lwood]

Re: Wrong dimensions - Help!!

We really need to see the flue(s) in closer detail. Post pictures. I really don't understand why the need to lower the dome. Raising the floor should get you out of the water and without pictures, we cant really see what you can do to modify the entry to get your proper proportions. I think trying to keep a refractory donut in the top of the dome would be a nightmare trying to keep it there in a 700F environment and having some sort of scaffolding in to hold it up would be a nuisance.

Let's look at your door/flue opening(s) and see what we can do as far as modifying that to get your 63% with the existing dome height.

Have you determined how your going to do the new hearth floor? what will the new dome height be? It was 30" now it will be ??? with the new floor and a 2" gap underneath. Let's say it ends up to be 24". That means you need a 15.2" door....There you go....your finished....assuming we are all measuring from the same place. Send pictures and we'll talk about it.

[peterthewolf]

Re: Wrong dimensions - Help!!

Brickie-
Thanks, and for all your input and photo posting (tomorrow's too). When it is done, (guess that will mean curing again), you'll get the first (photo) slice!!
-Peter

[brickie in oz]

Re: Wrong dimensions - Help!!

I hope you have a great final outcome from your oven experience Peter.

Youll have to invite us all for a virtual pizza once up and running..

[peterthewolf]

Re: Wrong dimensions - Help!!

Tenorio- I'll comment back within your text. Now we're getting somewhere!

When you think about lowering the dome, you have to take into account your current dome's final height in relation to the new slab+insulation+brick floor.

---P: Yes, I have registered that. If our existing floor remained where it is (that will change if we alter it of course), right now we'd just count the inches downward from dome peak for door at 63% when it's all done...Right? I think I've got that. The new floor determines how many inches to ultimately bring the dome peak down...which should happen AFTER the floor is done. OK.

(metal donut would work as well, although you have to be able to take out the forms holding your poured concrete in place, so you need a gap there...)
---P: If the forms are not combustible, why not leave them in? Isn't that exactly the thing that would keep support beneath the slab forever as in your drawing? For just those inches right against the joint of floor meets wall, and a center support as in your drawing, it wouldn't be air, but it would be a non-combustible, non-water absorbing medium of either fiberboard or metal - which ought to heat as part of the floor-wall mass anyway; isn't that ok? I mean, it's not much mass really.

I have never understood really where your inside flue is located, but you don't need an inside flue at all. It will probably be too low after the raise. Let the smoke go out the door - it does that in most of our oven designs as it is....

How about in the morning, I'll take one more photo or two to show you the existing flue. Very spiffy oven you have there! Meanwhile, imagine you can move through walls...just take the flue that is now sitting directly over your door, and make a mirror image- right there through that wall - but on the *inside*. That's exactly where our flue is now. It is located in the ceiling of the tunnel, eight inches around, just about 5 inches in from the door itself. Since your smoke travels out your door, then (being hot) immediately wants to rise, it goes right up that flue. Ok. If this flue (other than indoor ventilation issues) weren't there at all, yes it would suffice to just let the door do the exchange. But like I said last entry, wouldn't it also not matter (if we brought down the flue inside 3 inches to the same height at 15 inches) as the door is, wouldn't it be ok to let that smoke rise *before* it went out the door? Or is there something about air pressures at the in-out exchange of air vs. hot exhaust that needs to happen exactly *through* the door opening itself? We of course could find this out by making it the last step in the process, because again, we don't even have to mess with that flue in there at all - if we simply stop it's flow anywhere in or on top of that pipe so nothing will escape through it. It's just that if it (can) work still, hey, we have a nice flue pipe up there already. If you or someone says no, go ahead and waste it, then ok I would.

(BTW, you don't really need draw when your smoke goes out into open air. It's just to keep let it fly a little higher, and aesthetically nicer IMO) You could do yours sort of like this... (you have a metal hood to coax the smoke where you want it to go)
--Good, like I just said; at the end with fewer words, yes it's nice to have that just in case aesthetics can be there. If not, hey we'll let the smoke just come out the door like they did back before the afternoon Vesuvius burped.

So are we arriving at a sensible solution here or what? What you are laying out lwood is getting the closest to what I was hoping for - a solution that we might be able to handle, that we could direct our guy - or anyone else for that matter - to do, that I can understand as a concept with specific steps, that should both isolate the heat sink, make the right air flow, and bring in some effective and efficient burn so we don't have to deforest half the planet...and at the same time not have to tear this thing down. (Looking up close at the oven from the outside, it wouldn't be just dome that tears down; we really would have to nuc it all and start over).

If any of you who have contributed, or are simply reading through this research and discussion think we are being unrealistic, please tell us. Between all of you, you have all built, consulted, repaired or torn down others' mistakes and rebuilt ovens, or at least have contributed engineering knowledge. I value and thank you all for your generous time and attention on this. It's been quite a learning experience.

Next Saturday (a week from tomorrow) we will see if the mason will cooperate with our very direct and specific directions - with the materials that I will buy (deduct) this week out of the remaining balance on this oven, and have waiting here on site. Please write any last ideas, concerns or corrections if you have them everyone as soon as you can before then. I will report back in as we go, with the corrections.

(And Tenorio, stay tuned for the last couple of flue pictures tomorrow to tie it all up).

Thank you so much!
Peter

[Tenorio74]

Re: Wrong dimensions - Help!!

Peter,

When you think about lowering the dome, you have to take into account your current dome's final height in relation to the new slab+insulation+brick floor.

(metal donut would work as well, although you have to be able to take out the forms holding your poured concrete in place, so you need a gap there...)

I have never understood really where your inside flue is located, but you don't need an inside flue at all. It will probably be too low after the raise. Let the smoke go out the door - it does that in most of our oven designs as it is....

(BTW, you don't really need draw when your smoke goes out into open air. It's just to keep let it fly a little higher, and aesthetically nicer IMO) You could do yours sort of like this... (you have a metal hood to coax the smoke where you want it to go)