Door Arch Seal?
So, I'm on my second time trying to build my earth oven. I have a brick arch for the oven and I've (attempted to) cut a wood baking door. The problem is, no matter what I do, it seems that getting a door that fits perfectly in the opening is a huge challenge.
Of course, my arch isn't perfectly curved and the bricks in the arch have little 'nubs' in them in certain places, making it so cutting a perfect door is really difficult. I try to have a tight fitting door but if it's too tight I loosen my arch every time I try to remove it (because it pushes on the arch if I don't remove it perfectly straight)
What I'm wondering is, how tight does this seal around the door really need to be? I know, obviously, the tighter the better, but practically, what do you think? It seems that if I trimmed it so I had no problems getting it in/out I'd have about 1/4" all the way around it.
I'm also wondering if I'm inserting it properly. I just slide it into the opening and it stands up on it's own (it's made from 2x6), not leaning against anything....
Thoughts to improve my door? I may have to recut it after the oven is done this time....
Every book that I've read had suggested using a temporary form/template to build the oven door.
Perhaps you can still create the form, fill the crevice/cracks with mortar/cob and have something smooth?
Your oven door need not be perfectly air-tight. Since the chamber is otherwise sealed, there is little tendency for any drafts to develop once the fire is raked out. My own door simply rests up against the oven wall, overlapping by about an inch, with a heat reflector fitting inside the door opening. Perhaps more important than the actual seal, the door should insulate well. Mine is about 3"-thick wood and lined on the inside with two seperate layers of metal to discourage heat transfer. Never had any problems with heat loss. I posted some pics of the door construction here under the topic "Oven Door" -- it was posted about 17 weeks ago and is still on the first page of the WFO group page. I'd post a link, but this site rejects such links as spam.
ClimbHi
Pittsburgh, PA
PS: I just looked at the Oven Door post and see you posted a comment there back when it was originally posted. So the above is probably redundant. But the advice still stands -- just make it overlap the door opening an inch or so. If you're brickwork isn't particularly smooth and you need it to fit tighter, you could add some gasket material such as fiberglass or a gasket from a wood stove -- you can get that at stores that sell the stoves.
Although I've never done this particular task, generic handyman styles might be relevant, specifically:
I'd do all my trimming and adding and cursing on a piece of cardboard which is much easier to cut. (Cut too much? Just tape on an "extension". It will be real real ugly, but who cares; after all it's not permanent and nobody else will ever see it.) Only when I had it exactly right would I "trace" that pattern onto a piece of wood and cut the piece of wood. And I'd use a power jigsaw, as anything else (band saw, table saw, circular saw, hand saw, etc.) wouldn't be able to adequately follow the edge as it snakes in and out for voids and nibs on each brick.
You wrote: "I'm also wondering if I'm inserting it properly. I just slide it into the opening and it stands up on it's own (it's made from 2x6), not leaning against anything...."
The ovens that I am familiar with are typically built with an inner arch and an outer arch. The inner arch being a bit smaller than the outer one. This would allow you to build you door with enough tolerance to fit into the outer arch easily and still seal against the face of the inner arch. Sometimes the inner arch is not an arch at all, but rather a rectangular entrance into the oven. My feeling from reading your post is that yours is a straight shot into the oven with no inner arch.
A link to a photo of what I am trying to explain.
http://www.fornobravo.com/forum/photoplog/images/6393/1_100_1456.JPG
polo, you nailed it here. Something like this is exactly what I always suspected since it makes alot of sense. Unfortunately, Denzer mentions nothing of the sort in his book (as a matter of fact there's no hint in there about how your door should actually fit/seal in the arch)
This picture helps alot. I'm not exactly sure what I'll do now (since my arch is built) but it gives me ideas of things to try. Thanks!
The help I received via the enternet while I was building my oven was invaluable. It is gratifying to return the favor whenever I can. If you can post some pictures maybe we can help further. I'm sure that Climbhi could offer suggestions as well.
Over at Distributed Proofreaders I was proofing an old book that incidentally describes a sourdough bakery in the Canadian Northwest. The baker shuts the door and seals the opening with wet clay mixed with ashes (lute). The verb is also "lute". The baker was luting the oven door. (I had to look it up).