Insulated door design...

[OzOvenBuilder]

Hi all, just thought I'd share some pics of the door I've finally got around to making!
I've been picking up some tips on here from those of you who have already created, and have come up with what I hope will be very effective, (will update this thread once tested).

The front face is 6mm steel plate (maybe overkill) while the inside face and 50mm sides are 3mm plate.

The insulation is 2 pieces of 25mm thick calcium silicate board sandwiched together with a little fire silicone just to hold it there while constructing.

What I've tried to do is minimise the heat transfer to the front. You can see there is a small gap around 5mm between the sides of the insulation which I'm hoping will stop most of the heat from reaching the front face. The only transfer should be a little via the glass rope, plus some through the stainless steel bolts & thermometer which run from front to back.
To finish off I've used fire rated silicone to stick some glass oven rope around the edge where the silicate board is. This is for 2 reasons, to block heat escaping the edges by creating a seal of sorts, plus to cover the silicate board entirely so there's no chance of any of this dust reaching the inside of the oven.

Check out the pics, let me know what you think if I've messed up anywhere (apart from my welding skills), & I'll let you know how it performs.

Cheers!

Russell.

[m1mckinlay]

Re: Insulated door design...

Very cool, nicely done. I've been trying to figure out how to insulate my door and yours gave me some great ideas. I guess I need to learn how to weld...!

[buckeyebreadman]

Re: Insulated door design...

VERY nice job!.....quite similar to what I had envisioned for my door....although, I'll have someone else do the welding....

[Lburou]

Re: Insulated door design...

Very nice

How did you stick the glass rope?

[OzOvenBuilder]

Re: Insulated door design...

Very nice

How did you stick the glass rope?

G'day Lburou,

I just used a fire rated silicone, the same that's used on my old double oven homestead cooker we have in our kitchen. This stuff is rated for flame fires so I'm sure it should take the radiant heat after the coals have been removed.

Don't use too much either, as I've found with the kitchen oven after a couple of uses the rope will squash itself into place where it sits. Just a nice bead to hold it is all you need.

You should be able to find it at any good hardware.

Cheers,

Russell.

[david lyons]

Re: Insulated door design...

Very nice work!

That probe looks vulnerable to me though, I have a bad case of the clumbsies sometimes though.

Regards

Dave Ly

[OzOvenBuilder]

Re: Insulated door design...

Very nice work!

That probe looks vulnerable to me though, I have a bad case of the clumbsies sometimes though.

Regards

Dave Ly

Hi Dave,

Yes I agree, I tried to think of another method but no luck. I'll just have to be careful. I have a table about 1m2 directly to the side of my oven which I use to place hot trays/pots etc. It's made from old railway sleepers and has gaps large enough to poke the probe into & sit the door flat if need be.
I think as long as I don't drop it I should be ok!

Cheers,

Russell.

[mickyD]

Re: Insulated door design...

Hey Russell, very cool door. I only wish you posted this about 1 month ago. Mine is very similar to yours but my face is made out of hardwood floor boards. I used PVA glue on my insulation rope. Whish I had of thought of the fire rated silicon. Still holding together after a few firings though.

Mick

[OzOvenBuilder]

Re: Insulated door design...

Hey Russell, very cool door. I only wish you posted this about 1 month ago. Mine is very similar to yours but my face is made out of hardwood floor boards. I used PVA glue on my insulation rope. Whish I had of thought of the fire rated silicon. Still holding together after a few firings though.

Mick

Yes Mick, I wish I had made the door alot more than a month ago, but to be honest I've only recently decided to have a crack at some breads. I've been strictly pizza and roasts in iron pots etc...

My neighbor (who is very jealous of the oven & homebrew) likes to try breads but only inside, we're both very keen to have a go in my WFO.

The hardwood boards sound like a great idea. I'm a big fan of Australian woods!

Cheers,
Russell.

[cobblerdave]

Re: Insulated door design...

Gudday Russell

Re the probe don't have it fixed in position on the door.Mine"s loose so I just draw it out and pop it on the brick shelf at the front of the oven then remove the door and do whats got to be done. Just slide it back when the doors back on....been doing it for a good 6 mths...no probs no bent probe.
By the way neat door...wish I had the metal working skills


regards Dave

[Ken524]

Re: Insulated door design...

Great looking door! Mine is very similar and works a treat!

[OzOvenBuilder]

Re: Insulated door design...

Gudday Russell

Re the probe don't have it fixed in position on the door.Mine"s loose so I just draw it out and pop it on the brick shelf at the front of the oven then remove the door and do whats got to be done. Just slide it back when the doors back on....been doing it for a good 6 mths...no probs no bent probe.
By the way neat door...wish I had the metal working skills


regards Dave

Well I'm happy to report that the door works well! Whacked it on the other week after pizzas & it's keeping the heat in nicely.
Also did a slow beef roast the other day, fired the oven in the morning, last wood at about 10am and let this burn down with no door. Whacked the roast in after the oven had cooled at about 2pm, door on about an hour before this to even out. 3 1/2hrs turned a crappy bit of topside into sheer joy!
Glad it works well, I'm making one for a customer now!

Russell.

[Aussie Pete]

Re: Insulated door design...

Hey Russell, love the door, i think i'll end up doing one very similar, a few questions:

I was going to make the front plate, then weld the 50mm sides & top to the back, then wack in the silicate board, then weld the back plate on, any reason you didnt do this, it looks like you have your handle bolts going all the way thru the board to the back and nuts on holding back plate. Did you just use fire silicone to seal the back plate around the edges.
Also , the silicate board, what do you use to cut it with, have never seen it before.

Also, with this type of board, do you have any real time temperatures to see how well this type of board & set-up works. Say an inside high temp, and the temp at the front of the door.
Is your door very heavy, would you try & make it lighter if you had to make another one.

[mrchipster]

Re: Insulated door design...

I am very happy with my insulated door and it required no welding and is holding together very well..Strictly stainless steel pop rivets holding it together, Interior is stainless and outer sheet is aluminum because I ran out of stainless.

It maintains heat like you cannot believe. Last night made a roast and temp up to about 750. This morning 12 hours later temp average 550F. Even in this Minnesota winter average temp has been about 20F degrees right now. Last night it got down to 16F.

I can maintain heat for a while and usually still have 200F - 95C after 5-6 days.

Door is 4 inches of FB Board between stainless and Aluminum.

My Temp Probe does not work very accurately as it does not extend in to the oven it just barely reaches the back of the door (See last photo) and I made a small hole to allow heat to reach the probe. but it always seems to register about 150F degrees low.

I will eventually get a probe that is about 2 inches longer but for now it is fine I just need to add the 150F degrees. The nice thing is I will never whack it on anything.

Total weight of door is 17.5 pounds.

in a very high heat oven 750F+ the outside aluminum gets to warm to hold your hand on but it can be touched briefly without burning the skin. So I am loosing some heat to the outside by conductivity of the metal.

As you can see I used up about 40 rivets to hold the skins in place. One of my goals was to have very little of the ceramic board exposed so it did not shed fibers.

I will be building a lighter blast door that will have no insulation and also a lighter and thinner door for use when actively baking, I do need to use both hands to remove and place this door and would like one that I can put in and out with one hand.

Chip

[OzOvenBuilder]

Re: Insulated door design...

Hey Russell, love the door, i think i'll end up doing one very similar, a few questions:

I was going to make the front plate, then weld the 50mm sides & top to the back, then wack in the silicate board, then weld the back plate on, any reason you didnt do this, it looks like you have your handle bolts going all the way thru the board to the back and nuts on holding back plate. Did you just use fire silicone to seal the back plate around the edges.
Also , the silicate board, what do you use to cut it with, have never seen it before.

Also, with this type of board, do you have any real time temperatures to see how well this type of board & set-up works. Say an inside high temp, and the temp at the front of the door.
Is your door very heavy, would you try & make it lighter if you had to make another one.

Hi Pete,
I didn't weld the inside plate to the front & kept the gap to try & reduce the heat transferring from the inside. You can see the glass rope fills this gap, and the only thing that transfers the heat to the front should be the bolts and a bit through the temp probe.
I didn't use fire silicone fill where the rope is as the rope covers this well. I did fill the gap along the bottom with silicone where there's no rope.
Just cut the board with a jigsaw or similar, but make damn sure you wear some kind of breathing protection as the fibers are very nasty to inhale.
re the weight, I'm quite happy with it, & realistically I'm not putting on / taking the door off very often so it's not an issue for me.
I don't have any real temps, no thermocouples or anything like that. I just use the door probe as a guide to 'learning' what this particular probe says and how it behaves in my oven with whatever it is I'm cooking at the time.
Here's some pics of another I built with timber cladding, just used stainless screws to hold the timber.
Please put up some pics when you get it together, would love to see it!

Cheers,
Russell.