Forums:

Rocket bread oven in existing BBQ-site with salvaged oven

Benjamin Dinkel

Apprentice Rocket Scientist

Posts: 239

Location: Province of Granada, Andalucía, Spain

I like...

posted 7 months ago

10
Number of slices to send:

Optional 'thank-you' note:

Send

Hi fellow permies.

I decided to build a bread oven in an existing BBQ-site, using firebricks for the core and a salvaged electric oven as the oven part.

Here's a video of the first burn after dry stacking the J-Tube:

No smoke, I was quite content.
I then tried to make the whole setup a bit smaller and stacked it again, this time using the energy to cook some lentil soup.

I'll keep adding to this post as the construction continues.

1_BBQ-House.jpg

2_Insulated-base.jpg

3_Oven-dissasembly.jpg

4_Plastered-BBQ.jpg

5_Dry-Stack.jpg

5a_Smaller-Burntunnel.jpg

6_First-cooking.jpg

7_Half-brick-base.jpg

8_Burn-tunnel.jpg

9_Burn-tunnel-insulated.jpg

10_Burn-tunnel-insulated_with-Cobb.jpg

A good starting point to all RMH research: https://permies.com/w/rmh-resources
A good starting point for permies.com questions: https://permies.com/w/how-permies-works

Benjamin Dinkel

Apprentice Rocket Scientist

Posts: 239

Location: Province of Granada, Andalucía, Spain

I like...

posted 7 months ago

11
Number of slices to send:

Optional 'thank-you' note:

Send

It's done! Had a trial run yesterday and it worked quite well (after an incident with resin rich pine

)

Now I'm reviving the sour dough and really eager to start baking.

Also a little bit of cob work, maybe plastering left.

Any questions, feel free to ask!

11_riser-built.jpg

12_riser-insulated.jpg

13_oven-assembly.jpg

14_oven-installed.jpg

A good starting point to all RMH research: https://permies.com/w/rmh-resources
A good starting point for permies.com questions: https://permies.com/w/how-permies-works

William Bronson

gardener

Posts: 5170

Location: Cincinnati, Ohio,Price Hill 45205

1010

I like...

posted 7 months ago

6
Number of slices to send:

Optional 'thank-you' note:

Send

Benjamin, I love what you're doing there!
Do you have a deflector plate or any mass inside the oven?

Eating Bindweed
Eating Buckwheat Greens
Paul explains why I spend time here,better than I could myself.

Benjamin Dinkel

Apprentice Rocket Scientist

Posts: 239

Location: Province of Granada, Andalucía, Spain

I like...

posted 7 months ago

10
Number of slices to send:

Optional 'thank-you' note:

Send

Hey William,
thanks a lot!
I put a "pizza stone" in there. A 35cm x 35 cm tile of refractory material. It seals in the back, as to not let the hot gases short circuit.
It worked quite well, though I hope to get a higher temperature once the whole cob etc has dried out.

Tonight we're having a pizza party!

IMG_20240613_205801.jpg

A good starting point to all RMH research: https://permies.com/w/rmh-resources
A good starting point for permies.com questions: https://permies.com/w/how-permies-works

Benjamin Dinkel

Apprentice Rocket Scientist

Posts: 239

Location: Province of Granada, Andalucía, Spain

I like...

posted 7 months ago

11
Number of slices to send:

Optional 'thank-you' note:

Send

Pizza party was a great success. We made 12 pizzas in total, taking between 3-5 minutes per pizza. We used 1,5 buckets of wood for it, the fire got very hot. I am really pleased with it.

270D74AB-ADE6-4B52-A847-7D184A6CDF29.jpeg

A good starting point to all RMH research: https://permies.com/w/rmh-resources
A good starting point for permies.com questions: https://permies.com/w/how-permies-works

Thomas Tipton

pioneer

Posts: 337

I like...

posted 7 months ago

8
Number of slices to send:

Optional 'thank-you' note:

Send

I find this build very inspiring. I had a smallish electric oven that mounted in a wall cabinet that no longer functioned that I was considering doing something like this with. Unfortunately, it was destroyed in the process of removing it from the wall. So much for my plan! But your results clearly show that an oven can be repurposed in this way with very good results. It is a white oven, and I think that is a big plus. Have you thought about putting a thermometer on it?
Thanks for sharing!

Where there is Liberty, there is Christ!

William Bronson

gardener

Posts: 5170

Location: Cincinnati, Ohio,Price Hill 45205

1010

I like...

posted 7 months ago

8
Number of slices to send:

Optional 'thank-you' note:

Send

Wait, is it a white oven?
I thought the gasses hit the bottom of the refractory tile and streamed up and around it before exiting out the back.

This electric ovens does seem to consist of inner and outer steel boxes, with insulation in between the two.
Perhaps you could make a white oven by removing the insulation layer and running hot gasses through the emptied space.

Eating Bindweed
Eating Buckwheat Greens
Paul explains why I spend time here,better than I could myself.

Benjamin Dinkel

Apprentice Rocket Scientist

Posts: 239

Location: Province of Granada, Andalucía, Spain

I like...

posted 7 months ago

8
Number of slices to send:

Optional 'thank-you' note:

Send

William,
it is a black oven (the only white thing about it is the outside). You describe the way it works perfectly.
And yes, the electric ovens are basically 2 metal boxes with some insulation in between. I wouldn't use them to make a white oven but rather stick to the true and tested white rocket oven made from 2 oil barrels.

Thomas,
thank you for your kind words.
Sorry to hear about your oven being destroyed. I got this one from a second hand store for 7€. I'm sure you could find one for free or very cheap at a junk yard, as you basically only need the structure and it doesn't have to work.
Yesterday the thermometer arrived in the mail. I'll update you about the temperatures next bake.
I made some bread the other day and it was done quicker than in my conventional oven, so I expect over 250°C (480 F).

A good starting point to all RMH research: https://permies.com/w/rmh-resources
A good starting point for permies.com questions: https://permies.com/w/how-permies-works

Thomas Tipton

pioneer

Posts: 337

I like...

posted 7 months ago

6
Number of slices to send:

Optional 'thank-you' note:

Send

Benjamin. I see I misunderstood the part of it being a black oven. But isn't it true that by removing the insulation and directing the flue gases around the outer oven shell, the oven will still heat up, though perhaps more slowly? That had been my plan. To direct the post-riser flue gases around the oven, keeping the interior sealed off from the smoke.

Where there is Liberty, there is Christ!

Benjamin Dinkel

Apprentice Rocket Scientist

Posts: 239

Location: Province of Granada, Andalucía, Spain

I like...

posted 7 months ago

5
Number of slices to send:

Optional 'thank-you' note:

Send

It might work, but it also could be that the gap is not big enough. Also my inner oven box wasn’t all that sealed, lots of holes, that would then let flue gases in.
Also you would have no insulation then, probably loosing as much heat to the surrounding as you get into the oven.

A good starting point to all RMH research: https://permies.com/w/rmh-resources
A good starting point for permies.com questions: https://permies.com/w/how-permies-works

William Bronson

gardener

Posts: 5170

Location: Cincinnati, Ohio,Price Hill 45205

1010

I like...

posted 7 months ago

5
Number of slices to send:

Optional 'thank-you' note:

Send

Maybe you could plug those holes with refractory cement?
I think RapidSet cement could survive those tempatures, and its cheaper than refractory.
Set the inner steel box with the opening facing upwards and cast a slab in the "bottom".
Create an inner form and use it to cast the roof,,base and sides.

The barrel ovens generally have have an inner barrel, outer barrel, layer of insulation and metal skin.
You could immitate that by usung the insulation that you removed and some aluminum flashing.
Ive had good luck covering rockwool insulation with a cement coating over metal mesh.

Eating Bindweed
Eating Buckwheat Greens
Paul explains why I spend time here,better than I could myself.

Amy Gardener

gardener

Posts: 742

Location: 5,000' 35.24N zone 7b Albuquerque, NM

517

I like...

posted 5 months ago

5
Number of slices to send:

Optional 'thank-you' note:

Send

This project thread inspires me so much!
Thank you Benjamin for your genius adaptation of the rocket oven with your existing materials. I will absolutely rethink the possibilities for baking outdoors.
Congratulations on your success and please keep us informed of the modifications to your system. Did you plug the holes like William suggested?

sow…reap…compost…repeat

Benjamin Dinkel

Apprentice Rocket Scientist

Posts: 239

Location: Province of Granada, Andalucía, Spain

I like...

posted 5 months ago

6
Number of slices to send:

Optional 'thank-you' note:

Send

Hi Amy.
William was thinking about a possibility to turn a salvaged oven into a white oven. I went for black oven, I like the smell of fire and mostly bake savory things.
For the last bake I added some mass (4,5 fire bricks on top of the refractory pizza stone).
It reached 400F after 15 mins and behaved really well, forgiving uneven feeding intervals. Baked the whole bread with less than a bucket of small, old, round wood.

E9B07AC0-17B6-4AA5-B17F-853D0EB0AD52.jpeg

A good starting point to all RMH research: https://permies.com/w/rmh-resources
A good starting point for permies.com questions: https://permies.com/w/how-permies-works

Benjamin Dinkel

Apprentice Rocket Scientist

Posts: 239

Location: Province of Granada, Andalucía, Spain

I like...

posted 5 months ago

6
Number of slices to send:

Optional 'thank-you' note:

Send

It seems that once I included a photo somewhere in a thread as an attachment I can use the address and include it into other posts (as if using an image host).

This is a test.

PS: seems to work

1000020518.jpg

A good starting point to all RMH research: https://permies.com/w/rmh-resources
A good starting point for permies.com questions: https://permies.com/w/how-permies-works

Benjamin Dinkel

Apprentice Rocket Scientist

Posts: 239

Location: Province of Granada, Andalucía, Spain

I like...

posted 5 months ago

3
Number of slices to send:

Optional 'thank-you' note:

Send

Added a P-plate to protect the first brick of the roof of the burn tunnel today

A good starting point to all RMH research: https://permies.com/w/rmh-resources
A good starting point for permies.com questions: https://permies.com/w/how-permies-works

Yeah, but how did the squirrel get in there? Was it because of the tiny ad?

Rocket Mass Heater Jamboree And Updates

https://permies.com/t/170234/Rocket-Mass-Heater-Jamboree-Updates