Beautiful craftmanship

[dakzaag]

Re: Beautiful craftmanship

The clay is typical ceramic clay like you would use for a bowl or pot. Cheap and easy to work with.

It is probably not accurate to suggest that the hydraulic is better than the air set, it is more a matter of which is more appropriate.

If you really want to know what they were using, just send Alex an email and ask.

[S1MON]

Re: Beautiful craftmanship

If you really want to know what they were using, just send Alex an email and ask.

That would be the easiest

I was just asking out of curiosty really, it's not important exactly what type of clay I guess, just knowing that's how they build for easy dismantling was enough.

Further to my looking at the use of insulating fire bricks as it appeared they used, I found lots of values for similar materials, and it generally seems that the insulating boards are better. I did contact a supplier for data sheets for his particular items and here's the relevant data (to me anyway). It's all in metric I'm afraid

2300F (1300C)* grade insulation brick
Cold crush strength 2MPa, or 2N (per mm squared).
Thermal conducticity 0.23 W/mK at 350C (Lower is better)
Density 800 Kg/m^3

Calcium Silicate board (1000C grade)
Strength 2.6MPa, or 2.6N
Thermal conductivity 0.08 W/mK (at 200C)
0.1 (at 400C)
0.12 (at 600C)
Density 225 Kg/m^3

So whilst (for me at least) the board is slightly more expensive, it would appear to be well worth the extra on thermal conductivity alone. Being lighter and stronger is a nice bonus. If your supplier charges more for the bricks, then they're really not good value compared to the boards.

This has all gone a bit off topic...

* 2300F is 1260C, but sheet showed data of 1300C

[Tscarborough]

Re: Beautiful craftmanship

The airset/water soluble is really only suitable for minimal joints, <1/4", while the powdered one is normally fine up to and beyond half inch.

2x4x8 insulating firebrick around here are $7.00 each for a SqFt cost of $31.50, 2" ceramic board is $17.78 per SqFt.

Edit- Perlcrete works out to less than $2.00 per SqFt for a 4" layer, FYI.

[S1MON]

Re: Beautiful craftmanship

The airset/water soluble is really only suitable for minimal joints, <1/4", while the powdered on is normally fine up to and beyond half inch.

2x4x8 insulating firebrick around here are $7.00 each for a SqFt cost of $31.50, 2" ceramic board is $17.78 per SqFt.

The bricks differ in value depending on size. A 3" (76mm) thick brick cost less than a 2" one, and by volume offer the best value by far. I believe this is because it's the standard size to use, and is produced in far greater numbers.

So a 230x114x76 brick is ?1.49 + VAT -> ?1.79 (about $2.77 at the moment)
(9 x 4.5 x 3 in inches)

CalSil, 1220x500x75 is ?44.99 + VAT -> ?53.99 (about $83.68)

If my math(s) is correct,

Bricks are $9.81 per square ft, 76mm thick

CalSil is $12.74 per square ft, 75mm thick.

My supplier doesn't list ceramic fibre board, but I believe it's quite a step up in price here.

[dakzaag]

Re: Beautiful craftmanship

I think either brick or board is acceptable. The board is easy peasy to install and away you go. The brick would need to be set and probably leveled a bit. All of the insulating brick i have seen are fairly irregular, but I have not seen very many.

It really comes down to availability I guess. I have a hard time sourcing the board. (at least at a reasonable price.) That is why I started digging around looking at the insulating brick.

Mixing perilite/vermiculite/zonalite etc with a bit of Portland is by far the cheapest.