No announcement yet.

Oven Build - Magical Mystery Tour

  • Filter
  • Time
  • Show
Clear All
new posts

  • Oven Build - Magical Mystery Tour

    Hey there all you oven experts.

    As one will, I’ve been lurking and reading the forum for a few months (been bored for some reason) in preparation for building my own oven. Thank you for the wealth of information and testing you all have accomplished and shared. I’ll add what I can to the archives. Not sure which forum section is correct for a build thread but please move this if required. Also, way back in the day I ran a kitchen in an Italian restaurant where we used a wood fired oven daily.

    My plans change by the minute but I have started some materials testing and acquisition regardless. There are clearly easier ways to an oven than the road I’ll take, this is in part due to my frugalness and in part the diy-er in me. I’ll build the oven using homebrew refractory cement, bricks, pirete, cinder blocks and likely some stone decoration.

    That Base Inner Dome form:
    Ok, I know this will encourage some debate but I’ve decided and already built the mold using the exercise ball method. I understand the appeal of sand as the form and I very well could return back here to acknowledge my mistake but alas. The prospect of that much f’n sand everywhere in an already dusty and muddy mess, no thanks. Also, I’ve never been much of sand castle builder. I got the biggest thickest ball I could find, my floor will be 33.5” diameter with a ceiling height of ~17.5. I actually bought a smaller ball to use for the form of a rounded tunnel idea as well but have scrapped that for now.

    Refractory Home Brew:
    I’ve done plenty of wood work, construction, and auto bs in my diy history, this is the first I will have mixed cement in any form. I’ve done some research. I created a small scale test dome as a redneck testing vehicle for thermal reactivity and insulation. I molded a 1.5” 3:1:1:1 (with a pinch of sawdust too) mix over a stainless bowl and let it dry 24 hours carefully while spritzing. It turned out beautiful, then I covered in another 1-1.5” layer of pirete mix (more about that later) and then a thin layer of Portland with a pinch of sand. I let that setup 48 hours and again, looked marvelous. I sort of intentionally did not cover the bowl in any wrapping or lubrication to test how sticky this mix really was. It was real f’n sticky. The bowl was semi-permanent but had plan. I built a fire in the bowl with the demo dome upside down. Burned that fire for a couple hours solid and then sprayed it with a hose to, um, thermal cycling test it. Figured this would fairly quickly expose any fundamental flaws in my mixes. This thermal shock also allowed me to remove the stainless bowl due to the rapid contraction/expansion. Wow, I’m impressed, all the recipes essentially came from this forum and it works well(*). The inner dome after removing the bowl is ceramic glass smooth and only shows minor hairline cracks. I assume the stainless heating up in the fire caused the ceramic like kiln finish and don’t expect that over my balls surface in the end. There was some cracking around the crude mouth opening I installed on the outer layers but that’s to be expected. So next I built a fire under the dome as one traditionally would. Let this burn for 30-40 minutes and then, again, with the hose. Wow, magic cement. I basically tried to blow it up. As to the insulation bit. After the first longer fire and hosing, I waited about 5 minutes and then picked the bowl up to move it bare handed holding the exterior. It was plenty hot but not so hot that I couldn’t carry it 15 ft and place it where I wanted it to rest. 3 hours later it was nearly the same temperature, I probably exaggerate, but I was very surprised by the retained warmth given it’s small scale and por treatment.

    Pirete, Vermiculete, lava Rock, whetever.
    When reading the whole internet this was the bit I was most interested in, what to use, how it works, blah blah. I bought both supplements to test but already kinda knew vermiculite and I likely would not get along, the mix with that sh#t looks like loose cardboard and it disintegrates. Those perlite stones tho, that looked a lot more solid to me. Well, now I’m torn a bit. Also, confused/mesmerized by the prospect of the magic of ‘David S’ and his apparent ability to mix a 10:1 ration with that stuff. I maybe got it to 5:1, more likely 4:1 before it was in any sort of form I could handle without it falling on my shoes. I’ll try harder next time tho. Anyway, the size of perlite makes it tricky to mix leanly and vermiculate would be easier for that bit. Maybe a 60/40 P/V mix in my 4-6” insulation layer eventually? I dunno, the 4.5:1 seemed to work ok, very little water. Almost regardless tho, I think I could mix in chunks of Styrofoam (joking but only kinda) if I wanted to that layer. After all that research online and in practice I’ve learned one thing of value. The only good insulator is air. Create air (pockets), create insulation. Heat retention, a different story I know but lave sucks at that anyway by itself.

    That floor I’ve always dreamed about….
    This is the part that gives me the greatest heartburn.
    I know I should just order medium rate fire bricks at 5-6 dollars a brick. Well, F, that’s like 40-50 bricks potentially. I’m a cheap redneck, that like doubles my build cost or something. I may end up buying them (begrudgingly) but I found something else to consider. Been watching all the used sales (craigslist and such) channels as usual but lately for bricks. I came across a fellow with a load of extra bricks he brought back from Mexico. These are 100% red clay packed. I’d be more likely to call them terra cotta bricks when looking at them. I’d like to use these for the floor, on their sides, so a 4.5 inch floor base depth. I snagged 140 of them .30 a piece. I’ll use them for the exterior tunnel and base decoration regardless. One caveat and why they’re sideways. They…. Are…. Hollow. The outer wall is about an inch+ all the way around with a couple .5” cross members in there. These bricks are either amazing because of this, or a total tragedy. Either way, they’re beautiful. I am extremely curious to hear thoughts on these bricks from y’all experts.

    Mierda, that’s a lot of words, Pics attached, I’ll be back to run on more again later….


    apparently, 6 pics per post, see following posts

    Click image for larger version

Name:	89A3266A-0DD3-479A-A9D5-82C8F22445D8_1_105_c.jpeg
Views:	447
Size:	302.7 KB
ID:	426508 Click image for larger version

Name:	1C25E060-0D29-47A8-858B-0046D9BA05D1_1_105_c.jpeg
Views:	97
Size:	224.4 KB
ID:	426509 Click image for larger version

Name:	5D2EE7C7-AA3E-46FD-ABA9-5E3698C7CA41_1_105_c.jpeg
Views:	88
Size:	310.6 KB
ID:	426510 Click image for larger version

Name:	3C2E1C75-A6F1-4E24-B5F3-6A59E534DB4B_1_105_c.jpeg
Views:	73
Size:	386.5 KB
ID:	426511 Click image for larger version

Name:	D8BAA60A-A634-4CC6-8801-3F0920A1AB93_1_105_c.jpeg
Views:	76
Size:	270.8 KB
ID:	426512 Click image for larger version

Name:	4B88A116-5546-4E19-AF75-634526437F8D_1_105_c.jpeg
Views:	76
Size:	384.4 KB
ID:	426513

  • #2
    Click image for larger version

Name:	image_90953.jpg
Views:	76
Size:	334.6 KB
ID:	426519 Click image for larger version

Name:	image_90947.jpg
Views:	60
Size:	245.5 KB
ID:	426520 Click image for larger version

Name:	image_90954.jpg
Views:	62
Size:	363.9 KB
ID:	426521 Click image for larger version

Name:	image_90949.jpg
Views:	63
Size:	387.6 KB
ID:	426522 Click image for larger version

Name:	image_90951.jpg
Views:	81
Size:	221.8 KB
ID:	426523 Click image for larger version

Name:	image_90952.jpg
Views:	64
Size:	300.5 KB
ID:	426524 More Pics here...
    Last edited by fxpeak; 07-24-2020, 11:36 AM.


    • #3
      More pics, Bricks an 'at

      Click image for larger version

Name:	64056BEE-6CA1-4859-9A74-4A13F58A21F3_1_105_c.jpeg
Views:	88
Size:	179.5 KB
ID:	426526 Click image for larger version

Name:	DE05E56C-C6D3-4776-9192-EEF979F28ADA_1_105_c.jpeg
Views:	77
Size:	175.1 KB
ID:	426527 Click image for larger version

Name:	01F8EE08-305D-4B9C-A20A-150E860A652F_1_105_c.jpeg
Views:	75
Size:	162.1 KB
ID:	426528 Click image for larger version

Name:	7D875546-9BD8-4314-B755-122A68E09DA8_1_105_c.jpeg
Views:	62
Size:	300.5 KB
ID:	426529 Click image for larger version

Name:	342D4C71-3405-4D5E-B9E4-F799DBE93A09_1_105_c.jpeg
Views:	66
Size:	271.6 KB
ID:	426530


      • #4
        some early rough designs, really only relevant for loose scale at this point.

        Click image for larger version  Name:	image_90958.jpg Views:	3 Size:	116.7 KB ID:	426532 Click image for larger version  Name:	image_90959.jpg Views:	2 Size:	135.5 KB ID:	426533 Click image for larger version  Name:	image_90960.jpg Views:	2 Size:	144.3 KB ID:	426534
        Last edited by fxpeak; 07-24-2020, 11:44 AM.