Homebrew castable build, Newcastle UK

[UtahBeehiver]

Pictures can be up to about 1.25 mg and somewhere around 4-5 per post.

[Mullster]

Looking really good! I love the brickwork on the stand - gonna be a good looking oven!

[mesoiam]

Could've sworn I replied already, I must've got sidetracked.

Thanks David, I think I'll just leave them out and cure extra carefully.

Today's update: forged ahead and got the Calcium Silicate board cut into a keyhole shape, and poured the vermicrete slab (5:1 vermiculite and portland cement).

Edit: I'm not sure what's happening with photos, they are being resized to 83x111. Not sure if it related to the forum reset. Maybe I need to see about putting them on imgur or something.
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[david s]

The correct name for them is melt extract fibres, that may help your search. They are the recommended reinforcement for castable refractory, thin to increase surface area so they can dissipate their heat without creating expansion problems and stainless so they won’t corrode. It is the fine burnout fibres that are more important. Most manufacturers don’t add the melt extract fibres because they’re expensive and a bitch to work with so don’t worry if you can’t get them. If it were me I wouldn’t be using non stainless steel fibres as heat accelerates corrosion reactions and any rusting increases steel in volume producing more cracking problems. Try asking on the ukwoodfiredoven forum.

[mesoiam]

Yes indeed, cant be too careful.

In other news I've found it impossible to find stainless needles. I have some non-stainless needles on the way, the supplier says they have supplied to pizza ovens before, even mobile ones, and refractory made with these is used in incinerators etc. Could I ask the opinion here of the experienced members, are the non-stainless needles better than nothing or worse than nothing? I will be adding polypropylene fibres to the homebrew mix also. If anyone has a UK supplier who can supply small quantities I'd be very grateful.

Thanks for any help, and thanks already for the help so far.

[UtahBeehiver]

Dry cutting fire brick produces a lot of silica so be sure to were proper PPE.

[mesoiam]

Progress update: Cutting the firebricks at an angle for the herringbone pattern. The bricks are rated for over 1400 degrees, so the 45 degree cut was no problem.
Used a diamond disc which went through the firebrick easily, only a small grinder so cut from both sides. I identified the less perfect side and drove a chisel in, leaving the top with a nicely cut edge. I cleared up any overhang of the inner part with the grinder so they would sit nicely against the front bricks. It's only a couple of bricks, but it was exciting to see how the oven floor will look.

[mesoiam]

Yes I've seen yours and Mullsters posts around, watching intently also. Will post progress pics if I make any progress!

[aaronpizza]

Looks great - I'm about a week ahead of you on my build so I'll be watching this closely

[mesoiam]

Hello again. Unfortunately my thread was lost in the great hacking of 2020.
Anyway, I'm currently building a homebrew castable oven in Newcastle in the North East of England. I'm going for an 800mm ID dome, 50mm thick. I've had some advice from UtahBeehiver and where we left off I was going to check the specs of the CaSi Boards. I've since had the techspec from the helpful folks at Kilnlinings.co.uk, I can recommend the service there for anyone building in the UK.

Compressive strength is listed as 2.6MPa (377 PSI), can't remember what was suggested but it sounds high enough.
Thermal Conductivity:
@200 DegC 0.08 W/(mk)
@400 DegC 0.10 W/(mk)
@600 DegC 0.12 W/(mk)

My firebricks, calcium silicate board, fire blanket and fireclay have just arrived. Looking forward to laying out some bricks for cutting this weekend.
Still need to get sand and mortar but all the tricky things are either here already or on their way.
I may be spending some time outside B&Q in a socially distant queue this weekend but I'll be thinking about the nice things I can cook when it's all done.

Thanks everyone so far for their help (now unfortunately deleted)