oil drum oven (help required)

[pizza the action]

Hi guys it's my first post so please be nice
I'm in the process of building an oven after lots of research on here. I've got a steel drum inside another drum with a 25mm ceramic blanket inbetween after firing up the oven(which did cook pizza's) I'm concerned as the outside drum got too hot to touch! What can I do to rectify this? Double up the insulation to 50mm or could I cote the inside of the drum with a mix of vermiculite and concrete? Or maybe both. Any advise welcome
Thanks cliff

[pizza the action]

Re: oil drum oven (help required)

Anybody? I've been advised to put a mix of vermiculite and concrete under the bricks and on the back of the drum. Would it help to just coat the whole inside?

[jeeppiper]

Re: oil drum oven (help required)

More insulation. You only have an inch of insulation....I would bulk up as much as you can. I have 4-6 inches of insulation on my dome.

I don't quite understand your two-drum arrangement. Is one inside the other? What are their diameters?

[pizza the action]

Re: oil drum oven (help required)

Hi thanks for the reply I will add more insulation and see how that works. I'm restricted with how much gap I have between the drums tho. 2" will be fine but that's why I was wondering if there's anything I can coat the inside with.

[GianniFocaccia]

Re: oil drum oven (help required)

Nice rig. But if it were me....You would produce a higher-quality pizza if you filled the void between drums with a castable refractory cement and did as jeeppiper suggests: surround the entire oven with 4-6" of insulation.

Also, I'm wondering what is keeping those wooden legs from burning. If you could build a rectangular box out of steel studs and cement board, you could fill it with 6-8" of loose perlite or vermiculite (sides, back and top). Build a support slab and top it with 4" of vermicrete (inside your enclosure) and you'd be golden.

[TropicalCoasting]

Re: oil drum oven (help required)

You need thermal mass to heat up, then insulation to trap that heat.
Refractory cement between the barrels will give you the thermal mass
Then you will need to insulate outside the barrel.
Putting insulation inside the barrel isnt going to last or do much.

Something like this could be your finished oven
http://slice.seriouseats.com/images/...Barrel-ML1.jpg

[pizza the action]

Re: oil drum oven (help required)

The idea is for it to be a portable oven hence why I wanted ideas on if there is anything I could coat the inside with? Would a coat of vermiculite/cement be any good?
Thanks

[TropicalCoasting]

Re: oil drum oven (help required)

What are you trying to achieve ?

[pizza the action]

Re: oil drum oven (help required)

I'm trying to stop the outside drum from getting hot.

[cobblerdave]

Re: oil drum oven (help required)

G'day
Are those two shells completely separated by the insulation or are there some parts that do have contact? Ceramics pretty good insulation even if its just an inch.
I recon you must have some contact point and that's where the heat transfer is happening.
Regards dave

[v12spirit]

Re: oil drum oven (help required)

Yes. The two drums are coming in contact at the bottom if you have a look at the picture. If your only concern is to stop the outside from getting hot, just extend the insulation at the bottom, and look for any other contact points and fill them in between with insulation.

You may have noticed that the hearth stones that look to be basalt are rather thick for the drum thermal mass to let them heat up efficiently. They will bottleneck your oven. With steel ovens with such a minimum thermal mass a thin layer of stone will do, I would put about 1 cm thick stone on my steel hearth, and I would prefer brick being porous.

If you are limited with the available space between the drums and are ready to bother some extra effort, cut the inside drum alongside and shape it like a barrel vault folding the extra metal sheet as a hearth, the outer drum is already cut alongside. put insulation on the slab if any, then the inner barrel shaped drum, then the blanket layer(s), then adjust the outer drum to hug the whole thing and fix it by some means, and lay the thin layer of bricks on the hearth. But I reckon you want to let the thing as it is with the wooden legs and the drums intact. If so just insulate the contact points as Dave said.

What did you put under the hearth stones? Did you cook pizza in it? how long does it take to get to "60 mph"?