Show us your Door Thread

[TEDFB]

I scuffed the outer surface with the wire brush on a bench grinder to remove mirror surface

[TEDFB]

Thanks David, hope the photos are OK

[TEDFB]

[TEDFB]

[david s]

Try emailing the photos to yourself, which reduces and reformats them. Then use the emailed photos to attach to your posts.

[TEDFB]

Sorry I will try again tomorrow, the system keeps rejecting the photos

[TEDFB]

[TEDFB]

An explanation on my door, I used . 5/.6mm stainless steel for the bulk of the door, being made of 3 main sections,. The 2 flat sections, smaller one from inner arch template, the larger one from outer arch template making it with a lip to seal the dome.The center section I cut 130mm allowing 2 X 15mm lips to be bent to accommodate the 2 flat sections (a 20 mm lip would have been easier) Thin angle grinder slots were cut at fairly regular intervals to allow for bending the arch. I bent the flange out for the larger end and in for the small end. I made it long enough to bend into the flat base for about 30 mm. I used stainless steel angle for both flat sides at the base so it would slide without the sharp edges catching the oven floor. I used 4 strips of 25mm x 1.5 mm horizontally to strengthen the front as the handle would come on later. The front section I screw on with 5mm screws and the rear one with 4mm screws. Securing the rear one first to make it easier. I now had 100mm width between the two ends which I filled up with 4 layers of ceramic blanket through the gap left at the bottom, which I closed with a piece of the.. 5mm St steel which can slide in from the side. Put the handle on before the ceramic blanket, mounting it on 2 of the reinforcing plates. I then riveted some fire proof belting on the lip section. The door is surprisingly sturdy and weighs 4.2kg..I will attempt to post more photos here or separately, I am not great at getting them transferred from one place to another.

[rsandler]

Looks like you should call that Franken-door =)
It does make me wonder if a "beanbag" approach would work using Nomex with perlite/vermiculite as filling... you could push it partway into the doorway and it would mold itself to the shape and still be loose enough to remove. You could use it to plug the opening and still have a wood face to give it some rigidity to block the vent landing as well.

Worth a shot--might be tough to keep it from sagging, especially if you have it relatively thick. But, as long as it stays upright enough to block the whole oven mouth, doesn't really matter how it sags. And you might not need it that thick. I think David S has pointed out on other threads that loose perlite/vermiculite is actually a better insulator than CF blanket (although the concrete versions are significantly less efficient).

Worst case, cut the stitches with a seam ripper and fill it back up with something else. Small as it is, the little bobbin I got off Amazon has enough thread for a dozen doors.

[AJH]

Looks like you should call that Franken-door =)
It does make me wonder if a "beanbag" approach would work using Nomex with perlite/vermiculite as filling... you could push it partway into the doorway and it would mold itself to the shape and still be loose enough to remove. You could use it to plug the opening and still have a wood face to give it some rigidity to block the vent landing as well.

[rsandler]

Inspired by a post I saw somewhere (I thought in this thread, but a search doesn't turn it up) of using kevlar skids to make a door easier to slide, I thought "why not make the whole door casing out of Kevlar?" I used to do fire spinning back in college (still do occasionally), and we used kevlar for the fire wicks. If you can soak it in camp fuel and light it on fire, surely it could stand up to oven heat, right? It would be a lot lighter than metal, wouldn't conduct heat, and has a little bit of give, such that it would serve as its own gasket.

After doing a bit of research, I found that if you're going to use aramid fabric for a heat resistant application, you want Nomex, rather than Kevlar--it doesn't have as high of tensile strength, but has much better heat resistance. We're stopping heat loss, not bullets, after all. I found a source online (thefeltstore.com) that sold Nomex felt for a reasonable price, and ordered a small bobbin of Nomex thread from a seller on Amazon. Total materials cost about $50 for the fabric and thread, including shipping.

My door is made of two 2" thick pieces of leftover CalSil from my oven build, with a single piece of 1/8" Nomex felt wrapped around. I cut small wedges out of the top edges of the felt to let it fold down smoothly, and sewed a pretty rough seam with a curved "upholstery" needle. I then glued a wood facade (walnut with a spar urethane finish) onto the outside with a bunch of Liquid Nails Extreme. The door sits against the reveal of my inner arch, rather than going inside.

Total weight is about 11 pounds, most of that from the insulation (the CalSil boards are 7lbs by themselves), which is pretty good for a 4" thick door, I figure.

So far the Nomex is holding out great--soot covered on the inside, of course, but no sign of degradation in the fabric or the stitches after half a dozen full pizza fires. Heat retention is fantastic--I get 425F the next morning after a quick <1hour firing for just a couple pizzas, and had over 550 the one time I added a few more logs after finishing with pizzas in expectation of baking bread.

I think there's real potential for using Nomex as door exteriors. One could probably eschew the wood facade, and just sew on heavy duty straps (leather, perhaps) if you don't mind the look. One could even embroider the outside if you had the skill (I sure don't). Although you'd need to think more carefully about sewing good seams, I also think you could essentially sew a cushion cover out of Nomex felt and stuff it with CF blanket instead of CalSil, as if it were a pillow. That would reduce the weight substantially, and the additional give would probably make a tighter seal. Just would need to make sure it's stiff enough to hold it's shape.

Thanks for looking!

[david s]

No, this is a bad idea IMO. For my first oven I thought I was being clever and made the oven mouth and door slightly conical so that the door fitted nicely. The mistake was not to account for the shrinkage on oven cooling, when placing the cooler door inside the oven mouth. The result was the door jammed so tight in the oven mouth it was extremely difficult to remove. It is far better to have the face of the door sitting against the face of the oven mouth. For the same reason, this method is superior to a hinged door.

[rsandler]

Lots of great doors on here. A question for folks--thoughts on having the door go through the entry arch (like a plug) with a small lip of something to sit against the reveal, vs the body of the door sitting against the reveal? Seems like a majority of the door builds in this thread do the plug version, but a few do the other way, and I if I follow the pictures, there are some hybrids, with most of the door outside, but a small bit going into the arch. I also saw a build thread where david s specifically recommended not doing the plug approach. My first oven had the door built plug-style, but getting that to fit snug-but-not-too-snug was a pain in the neck. Trying to think through what to do on my current build.

[david s]

Very nice job. I’d be very interested to know how it operates. Not sure of the thickness of stainless you used, but it is notorious for warping from heat. The thinner the stainless the greater the problem. This can cause sealing issues against the rebate which can negate any gains in heat retention from the insulation.

[UtahBeehiver]

Great job on repurposing SS and use of ceramic glass.