Insulated door question

[jcg31]

Re: Insulated door question

Yeah, I expect this door to fail in many ways, the rustable steel being one of the most prominent, the wood being another contender. I haven't seen the fiberglass rope in the local HD or Lowe's, but maybe I didn't find the right section. What is the tape? How thick and wide is it? Do I need to apply it in several layers?

Take a look in the fireplace or wood stoves section for the cord. They will have the adhesive necessary as well. As for the tape, you will find a picture here:

http://www.fornobravo.com/forum/2/oven-door-6581-3.html#post57874

You will see that I have lowered my original offer made on this post (I am no longer charging for the tape), someone should get some benefit from this.

As mentioned earlier in the same thread, to construct my door I used a couple of layers of insulation board sandwiched between three sheet metal layers that act as "heat sinks". There is a channel around the edge of the door that holds the fiberglass cord and then 2.5" (by 1/8" by length to fit) fiberglass tape encloses the insulation board (see same thread for photo)

[papavino]

Re: Insulated door question

I wouldn't be too concerned about the interior of the door rusting out. I was using mine for a couple months and it didn't develop any rust on the interior (weldable steel) until I left the door fully exposed to the rain (d'oh). Even now it only has a couple spots on it. Nothing too severe.

[kebwi]

Re: Insulated door question

Yeah, I expect this door to fail in many ways, the rustable steel being one of the most prominent, the wood being another contender. I haven't seen the fiberglass rope in the local HD or Lowe's, but maybe I didn't find the right section. What is the tape? How thick and wide is it? Do I need to apply it in several layers?

[jcg31]

Re: Insulated door question

Hmmmm, unfortunately metal is a fine conductor, so wood on metal on brick will have the same problems as wood directly on brick, you will need some insulator material between the wood and the brick. Otherwise your results at the higher temps will look like my final experiment before committing to the raised panel.

http://www.fornobravo.com/forum/2/oven-door-6581-2.html#post54181

The fiberglass rope is available in any home center. The tape is a bit harder to find, but I have a large spool sitting around with no use in sight and if interested I will send you a length to accommodate your door for the cost of shipping it to you.

Jim

[kebwi]

Re: Insulated door question

The entire perimeter of the wood portion of my door will be wrapped, but only with metal. The question will then be, how much heat will the wood take through that interface. Probably alot, seeing as it's metal. I'll see how it goes.

[jcg31]

Re: Insulated door question

Kebwi,

The key to keeping your wood door from turning to ash is don't let any part of the wood touch brick.

http://www.fornobravo.com/forum/f2/oven-door-6581.html#post54043

The door above has been in use for more than a year, as you will see in the illustration it uses fiberglass tape and rope to make the seal with the oven and to prevent the wood from hitting any portion of the oven directly (including the floor). I used marine varnish for the finish and it too hasn't suffered from the heat, and this door has closed up temps 800+

Jim

[kebwi]

Re: Insulated door question

Good idea. I think I may have to rebuild the whole thing anyway. I'm building the interior out of weldable steel, and although most of it will be inside the oven most of the time, I suspect the entire thing will become 100% rust in a matter of weeks, which is shame because I'm putting way too much effort into building it. I like my design (photos when it's done), but my materials are probably going to turn out to be a failure.

[splatgirl]

Re: Insulated door question

I'm not sure I would bother but maybe you'll get better mileage out of this than I am envisioning. Maybe let your first one be the test dummy and decide from that if it's worth it to stain/varnish.

[kebwi]

Re: Insulated door question

Yeah, this is an experiment. The door is constructed in such a way that if the wood rots, burns, or is otherwise lost, the rest of the door is salvageable. I can unscrew the metal from the wood and either replace the wood periodically or put something else on in its place (metal).

Perhaps if you are saying it gets pretty hot, I should be concerned about staining or varnishing it. I wouldn't want that to seep into the oven and there won't be much outward draw during backing since the flue will cool down.

[splatgirl]

Re: Insulated door question

FWIW, the outer face of mine gets quite hot despite it being insulated.

[kebwi]

Re: Insulated door question

I've started building my door. The basic design is a metal box filled with foil-wrapped InsBlock 19, with a front face of oak, so the external face will be wood, not metal, although the edges will be wrapped with metal.

Question: the oak is currently unfinished, at least I think it is. Since this is the outside of the door, can I safely treat the wood in any fashion, say with a nice stain, or is that something I shouldn't expose to the oven? Other than merely staining for appearances, what sort of finish could be applied which might actually offer some protection against the elements. Everything in Washington ends up mildewy if you don't protect it somehow.

So, what kinds of finishes, if any, would be unsafe on the outside of a door, and what kinds of finishes would help protect the wood from warping, mildewing, or otherwise generally disintegrating?

Thanks.

[kebwi]

Re: Insulated door question

I eventually made a second door out of aluminum. I cut a piece of flat aluminum and made a pan that would hold the insulation that would fit inside the door. I bolted the two pieces together to complete the door. I get more heat transfer than I would prefer, but I can still cook for about three days after the pizza firing.

Yep, that's basically the design I was describing above, and I was curious about heat transfer. Thanks for the input.

Cheers!

[kebwi]

Re: Insulated door question

Hmmm, so that's a 'no' on "taping" the thing together. Good to know. I'm hoping all structural joins will be bolt/nut or rivet in my design.

[SteveP]

Re: Insulated door question

My original door was a pice of 1/8 in steel where I had sandwiched the insulation with some expanded metal, but I wasn't comfortable with the insulation exposed to the inside of the oven. I eventually made a second door out of aluminum. I cut a piece of flat aluminum and made a pan that would hold the insulation that would fit inside the door. I bolted the two pieces together to complete the door. I get more heat transfer than I would prefer, but I can still cook for about three days after the pizza firing. I belive the entire door cost about $60.

[texassourdough]

Re: Insulated door question

Ouch! That seems a lot for a door!
Jay