New Oven

[Jim Bob]

Foundation to my Forno Bravo spec'd oven is being poured as i write this. Anxious to see completed oven. Am taking pics of each step and will post some of them as soon as i download to computer. Question on the thermocouple thermometer: i have purchased a nice one from Cole Parmer with two separate probes. I understand i can build one directly into the hearth(concrete/vermiculite mix) and bring it thru firebrick floor. Any precautions to doing this and how far should it extend thru the floor? Too far and it will catch the peel. I assume also that the other should go in the ceiling and both leads can emerge thru the brick facade on the side of the oven. I will appreciate anyone's advice or experiences with these thermometers.
THanks,
Jim Bob

[james]

Re: New Oven

Hi Jim Bob,

You should set the thermocouple probes about 1 1/2" back from the inside of the oven, where they will pick up the absorbed temperature of the bricks.

Does that sound right to builders who have done it?

Also, do you have part numbers? I have been meaning to stock a nice two probe thermocouple and temperature gauge set in the FB Store for some time. If your installation works well, that might be the right solution for other builders.
James

[Jim Bob]

Re: New Oven

James,
Thanks for the quick response. The item#'s are: the thermometer itself is EA 94461-12 listed for $84. plus the insulated probes are EA 08439-62 listed at $29 each. I hate to be a dummy, but i am not sure i understand where 1.5" inside the oven actually is. Are you suggesting putting both probes in the floor just inside the opening? And by the way, i appreciate having the large knowledge base in this forum to draw from.
Jim Bob

[DrakeRemoray]

Re: New Oven

Welcome Jim Bob!!

[james]

Re: New Oven

Drill a hole in a cooking floor brick and the dome brick from the outside. That is where you put the probe.

Make sense?

I am still hoping other folks who installed thermocouples will jump in on their technique and results.
James

[Jim Bob]

Re: New Oven

James,
Thanks. Do i keep the probe level with the firebrick or have it sticking up a little on the floor and sticking out from the ceiling?
You know you really need to write a "Brick oven construction for Dummies" book, so i won't keep buggin you.

[james]

Re: New Oven

Hi Jim Bob,

It's the opposite. The probe wire sticks out -- away from the inside of the oven. You do not want to break through into the oven itself, and your probes are testing the heat of the bricks themselves, not the air inside the oven.

The wires run on the outside of the oven, where they hook up to your temperature gauge.

Helpful?

Great idea on the Dummies books. We should re-write the Pompeii Oven eBook 2.0 in the Dummies format. :-)

James

[Jim Bob]

Re: New Oven

James,

Good thing i keep asking questions. Man, i would really screw it up. The ceiling one makes sense, but on the hearth floor, think about it, the unmortared firebricks will be setting on a 4" hardened layer of concrete/vermiculite mix. Therefore I will need to bury the probe cable in that mix and leave the probe sticking up just enough to slide into a predrilled hole in the bottom of one of the floor firebricks. Am i still off base? Sooner or later i will get it!!!
Jim Bob

[SpringJim]

Re: New Oven

Welcome Jim Bob...I'm on the thermocouple learning curve as well.....

So far:

1) I'm installing tubes in the oven so the thermocouples can be replaced as needed. (I'm going to try a cheap plastic tube 40 cents per foot water pipe coated in petroleum jelly and try to remove it. First one is at the concrete / insulating layer interface....wish me luck)

2) Your dome or hearth temp probes may have a certain temperature rating that is okay for the oven but the wires may not have the same temp rating...something to check on where the wires will be near the oven surface!

3) I'm trying to decide whether to go with a meter and selector switch...or just put in the probes and use a hand held meter. It's primarily a cost issue.

4) For surface temperatures, the IR gun works well.

Good luck to you!

[Jim Bob]

Re: New Oven

SpringJim:
Thanks for the info. ALways glad to hear from other people especially in this construction phase. Don't want to screw it up. The thermometer i purchased from Cole Parmer is located at this website: Handheld Thermocouple Meters And Economical Type K/J Thermocouple Thermometers - Cole-Parmer Catalog
And if you will look at the accessories column on the right you will see the pvc insulated Type K cables @ $29 each. They are 5' long which should be fine. Until i receive them next week, not sure how dummyproof the instructions will be. As you can see those cables are rated up to 221 degrees F which should be ok.
Once my builder starts pouring the hearth slab next week, i need to be a damn expert and ready to tell him exactly what i want done. That is why I am pressing James so hard.
That meter will handle both probes, but it is rather expensive. But considering what my oven is costing($6,000!!)that is peanuts. That was the lowest bid I could get and since I am 68 yrs old, had no intention of doing it myself. Besides I couldn't lay a level course of bricks to save my soul. Biggest problem is that the crew is hispanic and we definitely are having communication difficulties.
after completed though i am going to be hounding everyone for great recipes, so my wife doesn't think I threw money out the window~!
Jim Bob

[cplain]

Re: New Oven

Welcome Jim Bob....

Since I haven't started building my oven yet, I've got a little time on my hands. So I threw together some graphics to illustrate about the thermocouple placement. Not as professional as what's found in the FB plans...but I'm just a frustrated pizza chef... Craig

[Jim Bob]

Re: New Oven

Craig,
Now that was a big help! Thanks very much. Do you think some type of cement or mortar is needed to hold it in place up in the firebrick? Also, the probes i purchased are 12" long and will need to be installed like your first attachment, down thru the entire hearth to work, i guess.
I also just realized that even though I am doing the walled enclosure instead of the igloo type oven, i will need a layer of insulfrax before filling the void with loose vermiculite. There were too many drawings and i overlooked it. Not sure if that stuff is available in Memphis. Where are you located? To post at 3:45 am you must be in a different time zone or a very light sleeper!
Jim Bob

[cplain]

Re: New Oven

Jim Bob:

You're welcome..glad I could help with that. Unfortunately I can't help with your question about setting the probe in place from any personal experience as I haven't built an oven yet...but doing a quick search for "thermocouple" in the forum I found a thread in which one builder used a little mortar to set the probe and provide good thermal contact. It's at:

http://www.fornobravo.com/forum/f28/...t-do-2164.html

As far as telling your crew about building the oven, I highly recommend downloading the Instructions/Plans from this site....lots of good diagrams in there to help you communicate to a Spanish speaking worker. Also, go through this forum and find some threads where somebody discusses their build all the way through with pictures. That will give you a good understanding of the process and some more pictures to help show your guys what to do.

Some good ones include The Badger Build:
http://www.fornobravo.com/forum/f21/...uild-3726.html

My Old Kentucky Dome:
http://www.fornobravo.com/forum/f21/...sure-3002.html

Or pick any yourself to look at:
Brick Oven Photos - Forno Bravo Forum: The Wood-Fired Oven Community

Until we move and I can build, I';m living vicariously through others via their threads...

Craig

[asudavew]

Re: New Oven

I've had 2 probes in my WFO for the last 9 months or so....


My oven was not finished.... I cut the wires while I began finishing. I didn't like the look of them sticking out and I don't really use them.... Just a thought.


Dave