Forno Bravo Forum: The Wood-Fired Oven Community

Forno Bravo Forum: The Wood-Fired Oven Community (http://www.fornobravo.com/forum/)
-   Introductions (http://www.fornobravo.com/forum/f3/)
-   -   Clay Ovens (http://www.fornobravo.com/forum/f3/clay-ovens-5788.html)

luca 12-16-2008 02:28 PM

Clay Ovens
 
Hi y'all!! I'm new to the forum, but have had a clay oven for about 6 years now and am thinking about making some changes to it. The positives are that it was real easy to make, with low cost (I paid a mason to make me the pedestal; otherwise all else was free from Mother Earth). The negatives are that clay is weather (and bug!) susceptible and needs to be protected. So, if anyone has any experience here (like any particular coatings that have worked as a weather barrier) I'd be interested in your experiences! Thanks!

Frances 12-17-2008 01:04 AM

Re: Clay Ovens
 
Hey luca, welcome to the forum!

I'm afraid I can't help with your clay oven questions, but I would be interested in more info about your oven. How big is it? How did you make it and what plans did you follow? Is it insulated in any way? How hot does it get and what do you cook in it? And (maybe most importantly) could you post some pictures?

We've had lots of people asking about clay ovens here, and it sems like such a good solution for people working on a low budget - so it'd be really really nice if you could provide some first hand information. :)

One idea, maybe you could build an enclosure round your oven to protect it? With a tile roof, like a lot of the ovens here have.

nissanneill 12-17-2008 03:01 AM

Re: Clay Ovens
 
Or put a superwool insulating blanket over your dome, cover with chicken wire and then render it!
The insulation would obviously help to hold the heat but more importantly act as a medium between the baked clay and the hard water proofing.

Oh hi Luca, by the way and welcome aboard.

Neill

Archena 12-17-2008 04:07 AM

Re: Clay Ovens
 
Hi!

And I'm afraid I can't offer anything experience wise either. My plans are to build an oven out of cob (clay) but it will be a while yet before I get started. At this point. I'm planning on an enclosure, possibly of papercrete with a sealant.

I'm curious about what kind of problems you've had with bugs. But anyway, welcome aboard!

luca 12-17-2008 07:14 AM

Re: Clay Ovens
 
5 Attachment(s)
I'd be glad to share my experiences with clay ovens (and will post some pics if I can figure it out!) A classic book on clay ovens is Bread Ovens of Quebec by Boily & Blanchette (it's out of print but available on the Internet). I used this for the clay mixture and construction methods, but came up with my own design and size since their ovens were gigantic (they could bake 30 loaves at a time for a week's worth of baking!). These classic ovens were bee-hive shaped, with the entrance 63% of the height of the interior dome height (a "magic formula" which gives best air circulation during firing, according to their research on scores of ovens). What I found most interesting is that they were all made of local clays dug by the builders near the ovens, which is exactly what I did here in KY (no commercial clay or specialty clay brought in from elsewhere). The only item that might have been purchased were the actual doors and door frame, which are usually an arched metal frame with two door panels opening in the center; otherwise, everything was made from local materials (e.g. a base was assembled out of large field stones, upon which was poured a concrete slab for the floor of the oven; then the rest was local clay). More later as I'm out of space!!

luca 12-17-2008 07:16 AM

Re: Clay Ovens
 
Quote:

Originally Posted by nissanneill (Post 47352)
Or put a superwool insulating blanket over your dome, cover with chicken wire and then render it!
The insulation would obviously help to hold the heat but more importantly act as a medium between the baked clay and the hard water proofing.

Oh hi Luca, by the way and welcome aboard.

Neill

This is a possibility, but I'm not sure what a "superwool" blanket would be (e.g. ordinary house insulation?) and what do you mean by "rendering" it?

luca 12-17-2008 07:25 AM

Re: Clay Ovens
 
Quote:

Originally Posted by Archena (Post 47355)
Hi!

And I'm afraid I can't offer anything experience wise either. My plans are to build an oven out of cob (clay) but it will be a while yet before I get started. At this point. I'm planning on an enclosure, possibly of papercrete with a sealant.

I'm curious about what kind of problems you've had with bugs. But anyway, welcome aboard!

Bugs love dirt/clay, which means if you cover it too tightly (especially say over the winter) cockroaches and other lovelies start boring holes in the clay for their nests! The solution so far has been to uncover periodically during warm days to expose the creatures to sun and predators, spray under the tarp with a bug spray,(not something I want to do frequently), or fire up the oven (which of course kills everything!).

RTflorida 12-17-2008 03:34 PM

Re: Clay Ovens
 
Luca,
superwool refers to a refractory insulating blanket, there are many manufacturers, most are comprised of ceramic fiber material - its sole purpose is insulating. All of this leads to a question - what are your heatup times and how well does your oven retain heat? A brick of refractory masonry oven needs as much insulation as possible to be worthwhile and effective. At least 2 inches of blanket, 3+ inches of vermiculite or perlite concrete, or a combination - blanket + vermicrete/perlcrete.
I have ZERO knowledge on Clay/Cob/Mud ovens, so I can't say whether you need insulation (I suspect it will help greatly)

Render refers to a finish layer of a weatherproof concrete - commonly referred to as stucco. Pretty cheap whether mixed yourself or dry premixed available at you local Home Depot/Lowes. If you go with the premixed, get the one with the acrylic additive - as others have said, it is nearly "bulletproof" and easy to work with.

RT

Archena 12-17-2008 07:57 PM

Re: Clay Ovens
 
Hi,

I love the pics. Thanks for sharing! One question though, why two openings? I assume the wooden thing in the background is some kind of roof that you put over it. Are you using a tarp as added protection? (Okay, so that was two questions...).

Note to self: make sure to use oven regularly! Bugs are icky!

Wiley 12-17-2008 08:49 PM

Re: Clay Ovens
 
Welcome Luca,
If you are simply looking at inexpensively waterproofing and bug proofing the outside of your oven you might look into whitewash or milk paint. Here's a link:

homestead recipes

Whitewash has been a traditional method of keeping bugs out of structures and making them waterproof. It's cheap and can be colored so the soot from the fire isn't as dramatic. Milk paint is the old standby that wooden barns were painted with and if you follow the link they have some good info on some combinations of the two (whitewash and milk paint).

I have a bit of a problem with spending a significant amount of money on ceramic insulation for a mud oven. By design mud ovens are inexpensive to build or rebuild as the need arises. Same issue with spending time and materials for rendering.

Again Welcome to the forum,
Wiley


All times are GMT -7. The time now is 07:14 PM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
2006/10 Forno Bravo, LLC