Brick oven reconstructed to a steel one

[v12spirit]

Re: Brick oven reconstructed to a steel one

There is a question I have about ceramic insulation blankets. Is it toxic? I mean after carrying it into home my hands started to rub a little and I had a kind of a cough! It lasted for just a few minutes then every thing was OK.

[UtahBeehiver]

Re: Brick oven reconstructed to a steel one

V12,

The CF blanket I used is Superwool which is a calcium silicate fiber blanket. The MSDS I have show it as a inhalation/skin irritant but not toxic. Here is a link to the MSDS.

http://www.allstateinsulation.com/pdf/DATA%20SHEETS/FASTWRAP%20MSDS.pdf

[v12spirit]

Re: Brick oven reconstructed to a steel one

Thank you beehiver for the clarification.

[UtahBeehiver]

Re: Brick oven reconstructed to a steel one

For those out there getting ready to install their CF blankets, wear a dust mask and gloves, and long sleeve shirt and even better, I think Brickie suggested buying one of those cheap paper throwaway coveralls when you install the blankets so you don't track all those little fibers into the SWMBO's washer.

[david s]

Re: Brick oven reconstructed to a steel one

Be careful when purchasing ceramic blanket. Some of them, Superwool included, have been exonerated from being classed as a class 2 carcinogen, while some have not.

[david s]

Re: Brick oven reconstructed to a steel one

If you clad the outside of your steel oven with castable, either reinforced or unreinforced, I would be expecting it to crack because of the sudden expansion of the steel, while the castable won't have had time to get hot being way less thermally conductive. However don't be too deterred because it's only there to add some thermal mass and provided you insulate well over it there should be no worries.

[v12spirit]

Re: Brick oven reconstructed to a steel one

For those out there getting ready to install their CF blankets, wear a dust mask and ....

Thank you beehiver for the safety advice. After having that rub and cough I cannot imagine the photos I saw on the forum for people handling the blankets without those protective stuff you mentioned.

[v12spirit]

Re: Brick oven reconstructed to a steel one

Be careful when purchasing ceramic blanket. Some of them, Superwool included, have been exonerated from being classed as a class 2 carcinogen, while some have not.

Hi david s,
I missed your posts on my thread but I expected that you will eventually post. Thank you for being such an active helpful member. I honestly learned lots from you and other kind people here.
You know I was just told by the salesman on the phone that he had a ceramic insulation and I ordered for one that was delivered luckily to my home with no damage. I think it is the only type of ceramic blanket available here. I think there is no way to know if it were carcinogen or not and even the salesman does not know, and if he knew he may claim that it is not.
If it were are the protective gloves and mask pointed to by UtahBeehiver sufficient to prevent any possible damage?

[v12spirit]

Re: Brick oven reconstructed to a steel one

If you clad the outside of your steel oven with castable, either reinforced or unreinforced, I would be expecting it to crack because of the sudden expansion of the steel, while the cartable won't have had time to get hot being way less thermally conductive. However don't be too deterred because it's only there to add some thermal mass and provided you insulate well over it there should be no worries.

david. There is another "cartable" in your post that needs to be corrected to castable I read your post and started looking for "cartable" in the dictionary then I knew it was a spilling mistake and that you meant castable. Then I was surprised that you fixed one of them ..
This may be a mad idea, but I'm trying to make my oven fast to heat up. I don't need the retained heat cooking. What is the benifit (to me) of waiting 90 minutes as in your castable oven, or even 45 minutes as in Wiley's oven which has steel in it cladded with basalt in order for the dome to clear while I can wait just a few minutes or up to 15 in an oven with less thermal mass? My belief is that the thermal mass favors two things: heat consistency and retained heat cooking, and that the thermal mass contributes nothing to getting a 2 min pizza out of the oven. The 2 min pizza is achieved by the current temperature inside the oven which is achieved by adding more fuel.
If I am cladding my oven I don't want to go beyond 0.5" thick. If I have to go thicker I prefer to not clad it at all; just 2 mm of steel with aluminum foil over it then the ceramic blanket. So what do you see?

[david s]

Re: Brick oven reconstructed to a steel one

david. There is another "cartable" in your post that needs to be corrected to castable I read your post and started looking for "cartable" in the dictionary then I knew it was a spilling mistake and that you meant castable. Then I was surprised that you fixed one of them ..
This may be a mad idea, but I'm trying to make my oven fast to heat up. I don't need the retained heat cooking. What is the benifit (to me) of waiting 90 minutes as in your castable oven, or even 45 minutes as in Wiley's oven which has steel in it cladded with basalt in order for the dome to clear while I can wait just a few minutes or up to 15 in an oven with less thermal mass? My belief is that the thermal mass favors two things: heat consistency and retained heat cooking, and that the thermal mass contributes nothing to getting a 2 min pizza out of the oven. The 2 min pizza is achieved by the current temperature inside the oven which is achieved by adding more fuel.
If I am cladding my oven I don't want to go beyond 0.5" thick. If I have to go thicker I prefer to not clad it at all; just 2 mm of steel with aluminum foil over it then the ceramic blanket. So what do you see?

I'm really not sure as I've not had experience with either building or firing a steel oven, however it is far more conductive than brick or castable, so will be both quicker to heat up and quicker to cool down. You could try covering it uncladded, with the blanket, fire it up and see how it performs. If you feel it needs some cladding to steady the heat loss then you could remove the blanket clad it ,then replace the blanket and start firing again.
Regarding the carcinogenic properties of the blanket, take precautions when cutting and placing it. Once in position and covered over, none of the fibres should be able to get anywhere near anyone so should be safe. The class 2 carcinogen means that tests on rats have produced tumours, but none have been reported in humans. I know lots of potters who have been exposed to this stuff on a daily basis and they're not too concerned. However I don't want to be producing a product for sale that includes materials that are classed as carcinogens. As a ceramics teacher I am not allowed to use ceramic blanket where children are anywhere near, but presumably the new "exonerated" ceramic fibre blanket would be acceptable.

[v12spirit]

Re: Brick oven reconstructed to a steel one

Thanks dave

[v12spirit]

Re: Brick oven reconstructed to a steel one

Hi mates,

My project has been delayed due to lack of materials, and I have been trying to get calsil bricks for the hearth for more than a month now.

I ordered the bricks after being assured by the masonry supplier that they were insulation bricks. They arrived today, but to my surprise, I found them not like the WHITE calsil bricks I used to see on the site. Rather, they looked like fire bricks!!!

Please tell me if these were insulating bricks or what ????

They are (11*23*6.5) cm, and they are about 2.5$ each.

[cobblerdave]

Re: Brick oven reconstructed to a steel one

G'day
It all comes down to weight so the pics don't help that much .
If its as heavy or heavier than a house brick ... More likely a firebrick.
If is really light in comparison to a house brick .. It should be an insulation brick.
Regards dave

[david s]

Re: Brick oven reconstructed to a steel one

Insulating fire bricks are a different material to calcium silicate insulating board. If the bricks are really light then they should be IFB's, if they're heavy, about the same as a solid red clay brick then they are probably dense firebrick.Looking at the pic, they look like dense firebricks to me.

[v12spirit]

Re: Brick oven reconstructed to a steel one

david, dave,
with the dimensions provided, how much must each brick weight? I'm gonna weight them to know what kind of bricks these are.