My new oven

[sacwoodpusher]

I bought a new wood fired pizza oven from my neighbor a few weeks ago. It was his "test oven". He has since modified the oven making a few cosmetic changes, for instance, the firebricks on either side of the door were replaced with red bricks matching the dome of the oven. He makes 10 of these a month, in red brick and black brick.

I even gave him a picture of my 3rd or 4th pizza to put on his website! (I built too big of a fire the first time I tried to bake pizzas and within 30 seconds they were incinerated. My neighbor came over and gave me a lesson, and now I build a small fire. 2 3" diameter logs, about a foot long are placed on top of the propane burner, and that is all the wood it takes to make enough pizza for my wife and kids. I have since learned that I can bake a batch of bread in the oven after the pizza is done, just let the walls of the oven drop below 450 degrees.)

[Jet_deck]

What are the safety features that this propane fired / wood burning oven employ?  Propane and wood fire in an enclosed area can be a disaster.  How do they keep that from happening?

[sacwoodpusher]

Good question,

The oven will not close completely. The steel door is lower than the door opening by a good 2 inches. The guy making them said he would not sell a full door because of the propane option.

The propane is supposed to be used to light the oven, and after the wood is lit, it is supposed to be turned off. Unless I am burning propane without wood, I turn the propane burner off after the fire is lit as the oven gets too hot.

[buceriasdon]

The net have several versions of wood fired style ovens with gas burners as an option. Wood fired, wood fired with auxiliary gas and gas fired alone. I admit I'm confused, so here the gas burner "option" is there just to start the wood fire but not to be used alone? Seems to be an odd "option" to me as it runs the whole length of one side it appears and very close to the wall.
Don

Good question,

The oven will not close completely. The steel door is lower than the door opening by a good 2 inches. The guy making them said he would not sell a full door because of the propane option.

The propane is supposed to be used to light the oven, and after the wood is lit, it is supposed to be turned off. Unless I am burning propane without wood, I turn the propane burner off after the fire is lit as the oven gets too hot.

[sacwoodpusher]

Go to one of the BBQ forums. This type of burner is quite common there.

As I said, I use the oven two ways, I light the wood with the propane burner, but can usually turn it off later. Alternatively, I have cooked things, pizza, steaks, chicken, and potatoes (red, cut in half, olive oil, salt, and pepper) with just the propane burner.

I am still learning how to cook with this oven, but what I do like in general, is cooking at a much higher temperature than I can indoors....the chicken is moister, and I can brown things better.

My favorite trick, throw chicken backs, neck, giblets into a steel frying pan with garlic, onions and carrots.....brown severly, and then toss in stockpot inside the house. I have never had stock so good.

[Jet_deck]

My personal opinion is that this user, is a user.  I  think that he is the builder, whoreing his cheap wares out to the forum.  I am willing to risk punishment from the powers that be if I am wrong.

http://norcalovenworks.blogspot.com/

http://www.pizzamaking.com/forum/index.php?action=profile;u=13337

http://www.pizzamaking.com/forum/index.php/topic,12557.0.html

 

[shuboyje]

Outside of numerous other potential issues with the ovens design the biggest issue is that burner is not safe.  If it was posted on an oven building site like fornobravo the reactions would be very harsh.

[buceriasdon]

Just a question, How is the burner not safe? Am I missing something?
Don
http://www.fornobravo.com/commercial_pizza_oven/gas_fired.html

Outside of numerous other potential issues with the ovens design the biggest issue is that burner is not safe.  If it was posted on an oven building site like fornobravo the reactions would be very harsh.

[shuboyje]

Brick oven burners need safety feature to insure the gas is burning.  Unburned gas can potentially accumulate in the top of the dome in quantities large enough to cause an explosion.

[buceriasdon]

I guess I was being too abstruse, wouldn't building a wood fire on top of a gas burner be considered unsafe with ash and the like filling the holes on the burner? Supposedly the gas burner is an option to help start the wood fire which quite frankly I don't believe for a second. But that's just me.
Don 

Brick oven burners need safety feature to insure the gas is burning.  Unburned gas can potentially accumulate in the top of the dome in quantities large enough to cause an explosion.

[sacwoodpusher]

I guess the first question is where would the gas accumulate? The oven interior is 13 inches high, and the ceiling is flat. The door opening is 8.5 inches high......and a little over 16 inches wide. There is a higher percentage of opening for gas to escape than most gas grills have.

The propane burner is a 3/4 inch pipe, schedule 40, and is sliced halfway through at 1 inch increments. The burner is removeable in about 3 minutes, but in a pizza oven, the ash left after a firing is minimal.

Why, after a fire is lit, would you want to continue to burn propane? I don't spend anything I don't have to. I think a tank of propane is about $15-$18 now. Wood burning costs me not much elbow grease and contributes to clean fencerows.

[Jet_deck]

Why, after a fire is lit, would you want to continue to burn propane?

Thats not the point. The point is that the oven builder should have the appropriate safety precautions in place so that 'joe public' CAN'T continue to mix the two fire sources.  Probably the same reason that the builder re-worded their ebay listing to discriminate the seperation of the two heat sources.

Another issue: "the oven will not close completely"  that is a wonderful safety device!  How many natural gas home ovens rely on this safety feature ?

"Go to one of the bbq forums.  This burner is quite common there"  Yes, it is a log lighter.  Not to be confused with a heat source.  In fact, the bbq forum that (the builder) put pictures of the same oven as yours (with their hunting dog) doesn't make much of an issue with a possible dual heat source.  However, another bbq forum has made a "sticky" of the correct way to build a log lighter with the appropriate safety measures to make sure that accidents don't happen.

Is their any way you can get your money back from "your friend"  the builder, so he can fix these general safety issues?  Also, let the builder know that he changed his blog, to remove his email address which matches the one you list as yours, here on the forum.

Lastly, do not google the builders email address.  It has a huge spreadsheet with names, email addresses and phone numbers.

[angman]

 
Goodbye Gary.

[buceriasdon]

Let's see, so the combination wood and gas fired ovens have a valve that shuts off the supply of gas if the flame goes out? Correct?
Don

[shuboyje]

I'd imagine it is similar to a gas fired furnace which uses a thermocouple to ensure there is flame.  Even with that though you still have the issues in a brick oven is the gas valve leaks at all, so I assume commercial models have safeties for that too.  In you furnace the flue is at the highest point or it has an inducer fan so the gas would simply vent out if the valve leaked.  In a brick oven if the valve leaked the gas would accumulate in the top of the dome since the flue should be 63%(give or take a bit)  of the dome height.  Imagine the valve has developed a leak and the oven dome is full of gas when you go to light it?  BOOM!!!  And that boom happens with your arm or arms in the oven lighting the burner from the looks of it. 

[buceriasdon]

So the lack of a chimney in this design creates a potential problem then?
Don

I'd imagine it is similar to a gas fired furnace which uses a thermocouple to ensure there is flame.  Even with that though you still have the issues in a brick oven is the gas valve leaks at all, so I assume commercial models have safeties for that too.  In you furnace the flue is at the highest point or it has an inducer fan so the gas would simply vent out if the valve leaked.  In a brick oven if the valve leaked the gas would accumulate in the top of the dome since the flue should be 63%(give or take a bit)  of the dome height.  Imagine the valve has developed a leak and the oven dome is full of gas when you go to light it?  BOOM!!!  And that boom happens with your arm or arms in the oven lighting the burner from the looks of it. 

[cranky]

Is propane heavier than air?

[shuboyje]

Yes, propane is heavier then air and natural gas is lighter then air.  That has crossed my mind many times but I don't want to be the one to make a blanket claim that propane is therefore safe.

[Jet_deck]

<a href="http://www.youtube.com/watch?v=xEsfBc7ohqY&amp;feature=player_embedded" target="_blank" class="aeva_link bbc_link new_win">http://www.youtube.com/watch?v=xEsfBc7ohqY&amp;feature=player_embedded</a>

[shuboyje]

Looks to have the same issue as most alternative type ovens...no top heat.  Looks like a bigger fire with open flame could help fix that but it seems like the person who built and is using the oven would know that and demo it properly.