Starting my barrel vault

[Les]

Re: Starting my barrel vault

The only cracks I have are the ones I pre-engineered in the back and front of the oven. I fired my vault the next morning after laying up and every I time worked on it after, since it was cold out.

A crack is a crack - I don't think they are a problem unless you are a plumber...

[jim81147]

Re: Starting my barrel vault

Well I burned the carbon off today . I was surprised at just how much wood that takes to accomplish The oven looks really nice now , not all nasty and sooty. Time to do some burns now so I can figure out timing , then on to making poolishes !!!

[mrchipster]

Re: Starting my barrel vault

Well I burned the carbon off today . I was surprised at just how much wood that takes to accomplish The oven looks really nice now , not all nasty and sooty. Time to do some burns now so I can figure out timing , then on to making poolishes !!!

The use of wood will tend to go down a little over time, I use less wood now to get my dome to clear than I originally did.

And the soot will return at the start of each firing.

Chip

[jim81147]

Re: Starting my barrel vault

Here are a couple more pics of my progress . Roofing and fascia board is supposed to arrive on wednesday.

[jim81147]

Re: Starting my barrel vault

here are a couple of the inside after my first full burn.

[gugahulk]

Re: Starting my barrel vault

Hi, I am building a barrel vault similar to yours. I notice you did not use any buttressing on your build. I am having a very hard time as i dont know how I would use it. Does your vault has any buttressing?

[david s]

Re: Starting my barrel vault

Gigahulk, here's a point you may want to consider. "The end walls of a barrel vault should be under the vault, not outside it." This is the general rule for kiln building, where temperatures are much higher and expansion is greater. The expanding vault has a tendency to push the end walls out and steel bracing is required to hold them in for kilns built this way. It is a bit more tricky to build the end walls first and then the vault over the top, but the result is better. The same applies for ovens although the problem is less because the temps are lower and thermal expansion is smaller.

[gugahulk]

Re: Starting my barrel vault

Gigahulk, here's a point you may want to consider. "The end walls of a barrel vault should be under the vault, not outside it." This is the general rule for kiln building, where temperatures are much higher and expansion is greater. The expanding vault has a tendency to push the end walls out and steel bracing is required to hold them in for kilns built this way. It is a bit more tricky to build the end walls first and then the vault over the top, but the result is better. The same applies for ovens although the problem is less because the temps are lower and thermal expansion is smaller.

Thanks david, here is my idea. I am not sure what to do with the buttressing situation, I am just affraid it might not hold and its holding my build. The first 4 courses are straight up on the sides of the vault that a low arch. See picture below. Any ideas you can give me?

[david s]

Re: Starting my barrel vault

This may help you.
Many folk decide to build a barrel vault rather than a dome in the belief that the construction will be simpler. Because of the barrel vaults inherent instability and problems to correct this, it turns out to be more complex. The only advantage a barrel vault has over a dome is its interior form which makes it more suitable for cooking large batches of bread.Other disadvantages are poorer circulation leading to cool spots, though this is more of a problem in a kiln than an oven.

[gugahulk]

Re: Starting my barrel vault

This may help you.

Yes, this helps. and its what I thought of doing however this will raise my mass on the side walls which is something I did not want to do. Any other way you can think of?

[gugahulk]

Re: Starting my barrel vault

This may help you.
Many folk decide to build a barrel vault rather than a dome in the belief that the construction will be simpler. Because of the barrel vaults inherent instability and problems to correct this, it turns out to be more complex. The only advantage a barrel vault has over a dome is its interior form which makes it more suitable for cooking large batches of bread.

Actually the iron is a good idea. But will that withstand the heat from the firebricks? Won't the iron get too hot?

[david s]

Re: Starting my barrel vault

Actually the iron is a good idea. But will that withstand the heat from the firebricks? Won't the iron get too hot?

No, the bracing is outside the bricks. With an oven the problem is that steel bracing would be covered with insulation making any adjustment at the nuts difficult.
Better to build the vault over the end walls and buttress, but skip the bracing IMO

[gugahulk]

Re: Starting my barrel vault

Better to build the vault over the end walls and buttress, but skip the bracing IMO

But the only way to do that is increasing my mass on the side walls right? Which is something i am trying to avoid

[okn]

Re: Starting my barrel vault

But the only way to do that is increasing my mass on the side walls right? Which is something i am trying to avoid

Not really, I braced mine with insulating board then welded steel bracing around it.

Take a look:

http://www.fornobravo.com/forum/43/thin-walled-barrel-vault-wheels-19037-2.html

Hope that helps.

[david s]

Re: Starting my barrel vault

Another alternative is to use insulating fire brick to buttress the walls.