Paso Robles Pompeii Oven Heat Retention

[Novaslo]

Hey Everyone,
I am starting this thread to showcase and discuss heat retention as well as door construction.

My Build is a 42in. Pompeii that came from the Forno Bravo Kit. I have 2". of insulation under the dome with the FB fiber board that comes in the kit. In addition to that I have 3" of insulation using the FB fiber blanket. I also have 1" of Perlite Cement mixture and stucco over the dome.

My first door was made out of 1/4" Steel with 1in of fiber blanket inside.
This door was good but my heat retention was not very good. Also the door was extremely heavy - about 40lbs - It was so heavy that the oven was difficult to use.

My original heat retention was about 3 days - After fully saturating the dome, I would be about 350 the next morning.
Following that about 200-240 the next. Day.

Attached are pics of my first door.

Then I set out to make the lightest door that I could possibly make.
It needed to be light and seal nicely. It also needed to be VERY well insulated.

The result as pictured is a door that is made out of Sheet Metal purchased at Lowes .22 Gauge.
Next I insulated it with leftover Fiber Board- 4"- The heat retention is fantastic.

Initial firing - 7-800 Degrees
Day 1 or the next day - 550-600 Degrees
Day 2 - 400 - 450 Degrees
Day 3 - 300 - 325 Degrees
Day 4 - 200 Degrees
Day 5 - 100 Degrees

These are rough estimates but suffice it to say that I am getting 5 Days of heat retention using this door.

Here are pictures of the original door.

Cheers

[Novaslo]

Re: Paso Robles Pompeii Oven Heat Retention

Here are pics of Door #2

This door was created using .22 Gauge steel sheets. (Not Galvanized)
It has 4" of insulation and was cut using a hand grinder.

We welded it all together and put in the Fiber Board.
A little paint and we are happy now.

The door weighs 15lbs - Much more manageable.

See pics

[DavidApp]

Re: Paso Robles Pompeii Oven Heat Retention

My door is made from steel shelving, not sure what gauge but it was handy and it was mainly a trial. It is 2" thick filled with ceramic blanket.

I have not done a temperature chart yet but having fired the oven on Friday night and cooked a Pork Shoulder on Saturday the oven was still at 135 degres on Tuesday morning.

I may try to make a better door as on this one the welding is not very good. Welding is not my thing.

David

[Novaslo]

Re: Paso Robles Pompeii Oven Heat Retention

Well your door seems to be doing a great job.
I plan to heat my oven to a very high temperature and then gauge day number two on trying to maintain something over 600

That would be great, as it is right now I am holding 500 after making pizza's and letting the oven sit for an hour or more after cooking.

Either way, with my old door I had trouble cooking bread on Saturday mornings after a friday night light

[DavidApp]

Re: Paso Robles Pompeii Oven Heat Retention

Hello Darin

It is working well but needs a bit of clean up work. The outer wood is made from pine and was not very dry so it shrank some and I need to line the oven contact surface with sheet steel. The wood is showing how hot the brickwork is. Also I need handles and have planned to put an air temp thermometer through the door.

I have just got a book on WFO cooking. It goes from Pizza all the way to drying herbs using all the phases of the oven.
The book is From the Wood-Fired Oven by Richard Miscovich. It is a great resource and I think it is written in an easy to pick up and read like a novel style.
He has a time and temp form that you should be able to download. I could not get it to work so I made a form.
Here is my attempt at a form.

David

[Blackfoot12]

Re: Paso Robles Pompeii Oven Heat Retention

Do you have a damper in your flu?

[texman]

Re: Paso Robles Pompeii Oven Heat Retention

this is my latest door attempt. 18ga steel from Lowes with fb board in the cavity and rope gasket seal between wood and steel and around steel. I have covered the rope with hi temp caulk to keep the nasty fibers in check. probably going to weld a strip to protect the wood and seal the fiber. i need to record some temps and check performance still. hope to post those sometime.

Texman

[Novaslo]

Re: Paso Robles Pompeii Oven Heat Retention

Hello Darin

It is working well but needs a bit of clean up work. The outer wood is made from pine and was not very dry so it shrank some and I need to line the oven contact surface with sheet steel. The wood is showing how hot the brickwork is. Also I need handles and have planned to put an air temp thermometer through the door.

I have just got a book on WFO cooking. It goes from Pizza all the way to drying herbs using all the phases of the oven.
The book is From the Wood-Fired Oven by Richard Miscovich. It is a great resource and I think it is written in an easy to pick up and read like a novel style.
He has a time and temp form that you should be able to download. I could not get it to work so I made a form.
Here is my attempt at a form.

David

Hi David,
Thanks for the spreadsheet.
I was able to use sheet metal throughout and the. Paint it. In the end as long as you like it and it is insulated, it will be great. The other thing is that it has to be as light as possible.
This is a very fun journey and the cooking is what it is all about. I cook literally everything I can think of in mine. Trying to use all zones that I can.
Enjoy it.

[deejayoh]

Re: Paso Robles Pompeii Oven Heat Retention

That is really interesting that you're getting so much better heat retention just from improving your door.

My oven generally drops to about 450 in the morning, and that's with a ~20g door with 2 inches of insulation. I'm thinking I may have to try out a thicker door.

As for door theory - I think a thin metal gauge door beats a thick metal door for sure. Thick steel is a real heat sink. Plus it's heavy!

[Novaslo]

Re: Paso Robles Pompeii Oven Heat Retention

The extra 2 inches of insulation does a couple of things. It works better than the other things I have tried. Not only helps retain more heat but with 4 inches it also stand up on its own. Being so thick it performs like a "plug"

I believe I can wake up to 600 degrees and will let everyone know here how well it can do.

Ultimately it was pretty easy to make, as long as you know someone that can weld.
��

[Novaslo]

Re: Paso Robles Pompeii Oven Heat Retention

That is really interesting that you're getting so much better heat retention just from improving your door.

My oven generally drops to about 450 in the morning, and that's with a ~20g door with 2 inches of insulation. I'm thinking I may have to try out a thicker door.

As for door theory - I think a thin metal gauge door beats a thick metal door for sure. Thick steel is a real heat sink. Plus it's heavy!

I agree with you.
The thinner the better. However the thin steel is really hard to weld. The welds burn right through.
We made it work. I did a good grinding job and rolled with it.

My door is now an insulated Plug!

Also I didn't say. Even still, it is 15 lbs.

[jimkramer]

Re: Paso Robles Pompeii Oven Heat Retention

Great thread you got going. So I see that your door is mostly a plug that slides inside the inner arch opening, with a bigger piece of metal for the outside, that covers some of the oven arch. I thought I would make my door taller and wider than the inner arch, so it sits in front of the oven opening, so that it covers and also hopefully insulates some of the brick that makes up the inner arch. You think that will help any?

[DavidApp]

Re: Paso Robles Pompeii Oven Heat Retention

Hello Jim

I think that you will get better heat retention if the door is a plug in the oven wall.

I am thinking of adding an extra inch to the thickness of my door taking it to 3". I have noticed that it feels warm so I am losing heat through it. I may be able to modify the existing door.

David

[Novaslo]

Re: Paso Robles Pompeii Oven Heat Retention

Great thread you got going. So I see that your door is mostly a plug that slides inside the inner arch opening, with a bigger piece of metal for the outside, that covers some of the oven arch. I thought I would make my door taller and wider than the inner arch, so it sits in front of the oven opening, so that it covers and also hopefully insulates some of the brick that makes up the inner arch. You think that will help any?

My first door was a cover over the inner arch with a protruding 1 inch of insulation. So that one inch went into the inner arch in "sort of" a plug.

It was made out of 1/4in steel and was basically a big heat sink. It was also 40 lbs roughly.

The plug was the only thing that made sense to me. Also being 4 inches thick, it stands up on it's own. There is no worry about it falling over when I set it down.

I am really happy with it.

[jimkramer]

Re: Paso Robles Pompeii Oven Heat Retention

Darin-

A few more questions:
-Does the ss buckle from the heat? I'm worried that if the ss is too thin, the seams could open up from movement.
-How tight a fit is the door? I would imagine it should have a little extra room to fit into the oven opening, for expansion of the metal.
-Do your metal handles get hot?