Oven Build 900mm - NZ

[wemme]

Well Like most visitors to this great site. We ended up with the "build an oven bug". We are in New Zealand and it's a right bugger to find proper materials and a small miracle if it's even cost effective...

Any way oven will be 900mm internal (~35")

So far we have....
200mm (~8") Reinforced foundation slab.
100mm (~4") 5:1 Perlite/cement insulating layer.

Still deciding on material i.e. brick or cast due to availability and Cost.

Regards
Bart

[KiwiPete]

Originally Posted by wemme

Well Like most visitors to this great site. We ended up with the "build an oven bug". We are in New Zealand and it's a right bugger to find proper materials and a small miracle if it's even cost effective...

Any way oven will be 900mm internal (~35")

So far we have....
200mm (~8") Reinforced foundation slab.
100mm (~4") 5:1 Perlite/cement insulating layer.

Still deciding on material i.e. brick or cast due to availability and Cost.

Regards
Bart

Bricks are not cheap in NZ, but I think cast is going to work out even more expensive. To save money, you could cut your bricks in 3's, rather than in halves. You won't get as much retained heat (but that's only going to be an issue if you want to bake lots of bread) but then again, you also should get quicker heat up times. Its all a matter of choices.

Cheers

Peter.

[Swampy]

I am building mine (80cm) from refractory cement from placemakers in huntly.$55 per 25kg bag.Probably looking at 8-10 bags.stll alot cheaper and more fun than buying one tho.

[wemme]

Hey Swampy,
Sounds good, keep us in the loop...
Unfortunately only master trade stock it here in Christchurch at $65+gst.
But i think your right and about 10 bags will do the job.
What are your dimensions going to be?

Any how after Fridays earth quake i need to fix the house first

[Swampy]

hope your house isnt too bad,was a nasty quake allright.
I just started up a build thread here if your keen to follow.

http://www.fornobravo.com/forum/f43/...ven-14201.html (Swampys Refractory cast oven)

[wemme]

I Managed to pick up these bricks today about 350-400 for $200NZD normally $4.5+gst each. they are made by a local brick manufacturer and used to line their kilns. they are made from "high" Al2O3 content Clay mixed with aggregates. they are 230x110x75mm @3.6Kgs so work out at about 2000-2100Kg/m2 which seems okayish however I'm still a little concerned about their specific heat capacity. I hope to test these as soon as possible any one done this before?

Regards
Bart

[Swampy]

they should be fine.if they are used to line their kilns they should be the go.
i just got some refractory concrete from troweltrade who got it from crow refractory.i got it home and its got shinagawa stamped all over it.wish i could go straight through them since they are just down the road.

[wemme]

Hey Swampy,
Yeah it looks like they make all the castable in NZ and yes they are a pack of bastards for not selling direct. still at least you can make a start now. I'm just starting on a test to see if these bricks are any good, will really loose my rag if these are insulating...
Regards
Bart

[Swampy]

you can tell if they are insulating by the weight.if they are light and smash easy with a hammer and the insides are like honeycomb,with lots of air pockets they are insulating but i think your fine.

[wemme]

Finially between the earthquake, weather, family and work. The build continues.
Tomorow i should have all the base fire bricks in and the dome support structure finished. I will curve some 3mm mdf over the area for the doorway and staple it in place.

Comments??

Regards
Bart