Thinking about making an insulated door, which has better insulation properties? Do they differ much, and does it matter all that much?
Hebel block vs. permiculite/vermiculite mix
I guess 7 cm thick would be plenty? much better than the thin aluminum sheet I use right now?
Announcement
Collapse
No announcement yet.
28" homebrew cast oven in walled enclosure Belgium
Collapse
X
-
Originally posted by Kris S View Post25kg vermiculite + 25 kg perlite 35 +/- 2/3 used 25kg bags portland cement 2 7.5 25 kg bags sand for dome mould and homebrew 3 5 25 kg bag fireclay 1 17 +/- 10kg hydrated lime 0 free
Looking back at the used materials overview from my post #102 I bought 25 kg fireclay, I don’t remember exactly how much I used but I still have some left, maybe a quarter to a third.
I can weigh what’s left over so we know for sure, I’ll try to do that.
Leave a comment:
-
Just realized I haven’t uploaded a pic of the finished oven yet apparently, so here is one.
Actually I still have some things left to do in order of importance:- Make a permanent chimney cap to keep rain out (the plastic bag solution is horrible)
- Make an outer ‘storm door’ to keep rain out of the entry
- tidy things up around the roof edges (currently just screwed a wooden board in place), don't know exactly what/how though...
- Apply a cement render over the base
- Paint the whole thing (better protection against rain than just a cement render)
- Make an insulated door for longer heat retention
- next year add a work bech / table top to the right
Last edited by Kris S; 11-02-2021, 01:44 AM.
- 2 likes
Leave a comment:
-
25kg vermiculite + 25 kg perlite 35 +/- 2/3 used 25kg bags portland cement 2 7.5 25 kg bags sand for dome mould and homebrew 3 5 25 kg bag fireclay 1 17 +/- 10kg hydrated lime 0 free
Looking back at the used materials overview from my post #102 I bought 25 kg fireclay, I don’t remember exactly how much I used but I still have some left, maybe a quarter to a third.
I can weigh what’s left over so we know for sure, I’ll try to do that.
Leave a comment:
-
I just finished casting my 32" dome and gallery. For done and gallery I used:- 200 lbs of sand for the dome
- I used some of the sand I used for the dome mould to cast the gallery a few days later, probably 30 lbs or so
- A bit less than 50 lbs of clay - I used up the complete 50 lb bag but used a few handful in the sand to build the mould for the dome
- Not sure on the portland cement and lime, but less than a bag each
- maybe 2/3 of a 94 lbs bag
- maybe 1/2 of a 50 lbs bag
Leave a comment:
- 200 lbs of sand for the dome
-
Look at Nick JC build, he did a really nice cast build and detailed out his materials.
Leave a comment:
-
Hi Kris,
Great build! I'm preparing to build an oven and will use yours as inspiration because I want to build 28" too. Can you remember how much clay you used in the homebrew mix in the build? I can only source by the kilo where I am so it would be great if you could let me know. Thanks.
Leave a comment:
-
Kris, David, thanks for your feedback. I think I will stay with my original plan of a 19" opening for a 32" diameter oven. I could always stand up some firebrick along the side of the opening if I want a smaller opening.
As far as the floor height, I have a bit of a challenge. There is a big height difference between me and my wife. I am sure I will be the one cooking in the oven, so I have chosen my elbow height for the cooking floor.
Leave a comment:
-
I agree about the more generous oven mouth. Mine is 16” wide, but for a 21” diameter oven that’s pretty wide for a small oven, but as it’s fuel consumption is so low it’s no trouble to flash it up. Plenty of retained heat for roasts and bread etc.
I think for working height you just get used to whatever you have.
- 1 like
Leave a comment:
-
Hi Andreas, I went for 19” width and 8.7” height.
If you can, I would advise choosing opening width over pondering about eventual heat loss.
With my rather small 28” diameter oven a 19” opening is pretty large and I probably lose quite some heat, but I’m happy I didn’t go smaller than that, it would not be practical.
19” is adequate but not luxurious, any smaller and it would annoy me I think.
I have done pizzas, a roast chicken, pasta sauce, some vegetable casseroles, 2 breads, some bbq ribs…
Something minor I would do different is have the oven floor higher, now the height of the floor is about 130cm I think (should remeasure to be sure), I would add 20cm to this, because I have to bend a little too much for loading and unloading. (I’m 1m87cm tall). But aesthetically I went for a little lower, should not have done that.
- 1 like
Leave a comment:
-
Kris S , What opening did you go with? I am planning my oven and hope to cut the brick this weekend, then cast the dome. I am planning on a 32" internal diameter and am going back and forth between a 17" and 19" opening.
Larger opening = easier access
Smaller opening = more thermal mass, should retain heat better for cooking
Have you used the oven with your door size for pizza yet?
Leave a comment:
-
Originally posted by Kris S View PostFair enough, I'll see if I can find it anywhere.
Sodium silicate goes under a lot of names, and I see both potassium silicate and sodium silicate products are being used for waterproofing (not my purpose), so can either of these be used for what I want to do, or should I specifically search for a sodium silicate product (with the correct CAS nr. 1344-09-8).
on a side note: the oven seems to have survived saturday's pizza firing without further cracks, but I'll wait and see this week when it's fully cooled down...
Great that no more cracks formed. I have some 10-15 fires at 1100-1300 F dome temperature with no issues no. The cracks appeared at fire 2-3 during cooling.
Leave a comment:
-
Originally posted by david s View PostHi Chris,
Any large refractory section is vulnerable to cracking, primarily because of the difference in thermal expansion. A one piece dome in particular, using wood as a fuel is particularly susceptible. For this reason most cast oven manufacturers offer their ovens in multi piece sections. This makes things more manageable and less weighty sections. For mobile ovens some manufacturers offer a single cast dome as they're less likely to have problems with road vibrations. When I first began to build ovens I used a single piece cast dome, but now produce a 3 piece dome. Unfortunately this requires much more work to create a mould, particularly if the sections are to be step joined. This is hardly worth the effort for a single cast oven, the simplicity of the single cast, in situ, over a sand mould has way more advantages. The single cast does however have a tendency to produce a crack, just like yours has, which runs vertically right opposite the oven mouth.
Leave a comment:
-
Fair enough, I'll see if I can find it anywhere.
Sodium silicate goes under a lot of names, and I see both potassium silicate and sodium silicate products are being used for waterproofing (not my purpose), so can either of these be used for what I want to do, or should I specifically search for a sodium silicate product (with the correct CAS nr. 1344-09-8).
on a side note: the oven seems to have survived saturday's pizza firing without further cracks, but I'll wait and see this week when it's fully cooled down...
Leave a comment:
Leave a comment: