36" build in Tallahassee - AKA Bruce's Folly

[cobblerdave]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Gudday Bruce
Sorry not a big one on the math. Are you going to to build you oven on the hearth brick? If you are this will change the weight distribution as the domes weight will carry more brick surface than it would on a 1/2 brick width.
Anyway I wouldn't be worried as plenty of ovens have gone before and no reports of them sinking into the insulation. Forno builds commercial as we as domestic for sale if there was a problem I am certain they would here about it quik smart from the public.

Regards dave

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Hi Dave,

Gudday Bruce
Sorry not a big one on the math. Are you going to to build you oven on the hearth brick? If you are this will change the weight distribution as the domes weight will carry more brick surface than it would on a 1/2 brick width.

Plan to build outside the floor. At this point I am currious as to whether 5 psi is the actual average load based on estimated weight and restricting load bearing surface to the 1/2 brick circle. It seems ridiculously low, particularly considering that much of the load would actually be spread over much more surface area. In fact it sound like I need to tie the dome down to keep it from floating away.

Anyway I wouldn't be worried as plenty of ovens have gone before and no reports of them sinking into the insulation. Forno builds commercial as we as domestic for sale if there was a problem I am certain they would here about it quik smart from the public.

Regards dave

That has been my thinking, particularly in relation to Kbartman's worries. My concern was that there might be just enough extra compression in the bio-sol to cause a problem. Doesn't appear to be an issue. So no worries (unless informed otherwise). Looking forward to getting the brick laid out on the hearth so I can make any final adjustments.

A few questions regarding the next step:
1. After I butter the CF board the slurry mix is spread (sounds appetizing). I have a bag of fire clay and also the fire brick dust from the saw. Is there a preference between the two? Also does the coarseness of the sand matter?

2. Many suggestions to mix small amounts of mortar at a time. If I end up needing to mix additional, can I just add mortar mix and water to the bucket and mix or does the bucket first need to be rinsed of any remaining mortar from the first round?

Thanks again for your help. Bruce

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

I laid out the bricks on the insulation. They are lying flat and level. I took my peel out and it did not have any problems sliding over the floor. One brick has a slight ridge and I can either grind it down or replace with another brick. Taking a break now. Later I will double check for level. Does the slurry serve any purpose beside leveling?

[kbartman]

Re: 36" build in Tallahassee - AKA Bruce's Folly

I laid out the bricks on the insulation. They are lying flat and level. I took my peel out and it did not have any problems sliding over the floor. One brick has a slight ridge and I can either grind it down or replace with another brick. Taking a break now. Later I will double check for level. Does the slurry serve any purpose beside leveling?

Agree that your floor looks very good, could you describe your technique (e.g., type of sander used ect...), either on this thread or on yours? Thanks, Bruce

Bruce,
No sander involved, just play sand purchased at the local home improvement store. The fire brick and substrate is not perfect has some imperfections causing misalignments and unevenness. Remembering brick pavers and the sanding between the joints I thought the sand would do the same for the floor. The sand flows, thanks to gravity and the spray bottle or water hose on the pavers ( I would not recommend a water hose on the oven floor do to insulation becoming saturated) to fill all the imperfections. As the sand flows downward to fill all imperfection the bricks become tightly locked together. I believe the brick and sand on substrate will behave as one unit with gravity to keep the floor level. As I worked the sand into the joints and rocked the brick to levelness I paid more attention to the corners off the herring bone pattern that the pizza peel would chip easily. I made sure they were below the 45 degree angle of the herring bone pattern to the oven door of adjacent bricks. I started with a rubber mallet to get the sand into the joints, and then tried the spray bottle. It worked wonders to allow the sand to disappear into the voids. Thinking the hammering of the rubber mallet and too much sand could cause to much outward expansion (too much could cause the bricks to expand to the oven walls causing my expansion joint disappear or fail. I was carful around the edges and figure ash would complete the job. As far as gritty pizza I figure a vacuum cleaner to remove just enough sand and ash would fill the left voids and prevent the gritty pizza.

As requested Bruce, floors looking good.
As for the slurry I?m not sure I thought it serve mainly as a leveling agent also might have some bonding characteristics. Hence no butter for me.

[kbartman]

Re: 36" build in Tallahassee - AKA Bruce's Folly

I'm still hoping someone will check my math on this, still seems very low.

My rough estimate: (Math for dummies like me) 1 brick 4.5 x 9= 40.5 sq " 8 pounds each brick X 10 courses over the brick=80 lbs = average weight on each brick around the dome /40.5sq"= 1.97lbs per sq" over the sama area of the substate............I might tie mine down also.

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Gudday Bruce
Easy to remove arch guide. Measure out your size /shape and cut out 2 pieces of ply/chipboard etc, make sure you factor in less in height to account for a couple of thin shims under the bottom.
Screw a couple of battens of wood on to the first template horizontally. Screw the secound template to the wood battens. Take you saw and set to cut through the depth of you template material. Cut through both side of the templates vertically.
The resulting guide now is held together by the wood battens and when the arch is finished is a case of unscrewing the pieces for removal. I have used this twice now and it works well and doesn't take much effort to build.
Screw the arch guide back together and keep it for a door template. As for a door, mine weights 9 kg that's a little heavy and I suspect other types are a little weighty as well. It will just have to be one for the forum when the time comes.
Regards dave

Well I finally got to work on the door/arch template. I made it full size and thought I could cut the bottom down later, when I actually start on the arch. I plan to leave a small gap an either side to allow for expansion of the metal door. Hence wouldn't removing the shims be enough to allow easy removal?

[cobblerdave]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Gudday Bruce
Definitly shim it, you will not get it out otherwise.

Been thinking about you door. So I have put a rough plan together. Now dont laugh Im not a metal worker, but this is what I have come up with.




I hope you like the look? I was trying for that 18th centery industrial type effect.
The first question would be about getting the steel and getting it bent. I am sure if you rocked up to the local engineering shop in your chair with a stack of oven pics and a cardboard pattern you would make an impact. I'm sure it wouldn't be to expensive its only a small job.
The handle is made from welders hammer handle they are cheap and easy to obtain. The inner bit covering the cal sil board will have to be made a very loose fit otherwise as it heats up it will jam in your entrance.
The sheet metal fold looks a bit filddly but I sure you could prove the pattern first by constructing the inner skin from cardboard and tape. You could use aluminium sheet it cheap easy to get and easy to cut with pr of tin snips. To get the long bits to fold just clamp along the fold lines two pieces af angle iron and tap it over with a rubber mallet. Flat headed brass bolts with the nuts on the outside face should hold it together and look good. If you reclain a seal from an old oven that would be good but the stuffs easy to get from industry cooking suppliers.
Anyway its a start and like most ideas it will probly spawn a new idea.

Regards Dave

[cobblerdave]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Gudday Bruce
What was I thinking make it all out of aluminum! 2 mm plate for the front face as well you could bent that. Would certainly make it light weight.

Regards dave

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Gudday Bruce
Definitly shim it, you will not get it out otherwise.

In your post you had both the shim and the vertical cut through the template. I wasn't able to see the need for the vertical cut in addition to the shim. Am I missing something?

Been thinking about you door. So I have put a rough plan together. Now dont laugh Im not a metal worker, but this is what I have come up with.
[ATTACH]35171[/ATTACH]
[ATTACH]35172[/ATTACH]
[ATTACH]35173[/ATTACH]

I hope you like the look? I was trying for that 18th centery industrial type effect.
The first question would be about getting the steel and getting it bent. I am sure if you rocked up to the local engineering shop in your chair with a stack of oven pics and a cardboard pattern you would make an impact. I'm sure it wouldn't be to expensive its only a small job.
The handle is made from welders hammer handle they are cheap and easy to obtain. The inner bit covering the cal sil board will have to be made a very loose fit otherwise as it heats up it will jam in your entrance.
The sheet metal fold looks a bit filddly but I sure you could prove the pattern first by constructing the inner skin from cardboard and tape. You could use aluminium sheet it cheap easy to get and easy to cut with pr of tin snips. To get the long bits to fold just clamp along the fold lines two pieces af angle iron and tap it over with a rubber mallet. Flat headed brass bolts with the nuts on the outside face should hold it together and look good. If you reclain a seal from an old oven that would be good but the stuffs easy to get from industry cooking suppliers.
Anyway its a start and like most ideas it will probly spawn a new idea.

Dave, can't tell you how much I appreciate this. I had been thinking in somewhat the same direction but had no idea where to start. Particularly the folding of the metal without investing in more tools. Would not have thought of using the angle iron to do the folds. Love the diagrams. Lots to digest and work through. Would aluminum work?

I like the idea of thermally isolating the front plate as mrchipster described on the second page, post #17.

http://www.fornobravo.com/forum/28/insulated-door-design-17110-2.html#post126601

I doubt that I can get the floor to sit any better then it already is, so I may forego the butter and slurry sandwich. Any thing I should do or consider before mortaring the perimeter bricks?

[brickie in oz]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Gudday Bruce
What was I thinking make it all out of aluminum! 2 mm plate for the front face as well you could bent that. Would certainly make it light weight.

Regards dave

My whole door is made from aluminium?

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

My whole door is made from aluminium?

Hi Al,
What gauge or thickness did you use? Bruce

[brickie in oz]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Its about 2mm or 16 gaugeish.

[cobblerdave]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Gudday
Remember that door now, the one with the hands on! pretty cool Brickie

Bruce perhaps another layer of that door seal between the two layers then you would only have the bolts to transmit heat?

Brickie did you include some type of "heat break" in your door?

Regards Dave

[brickie in oz]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Its got a sheet of 40mm cal sil inside it.

Edit:-
A pic for Bruce.

[Bec1208]

Re: 36" build in Tallahassee - AKA Bruce's Folly

Al, good looking door. I hope those are helping hands.