Which cinder blocks dont go boom!

[LT72884]

Ello, i have plans to build a cool brik cooker for pizza. I saw it on youtube the other day. Pretty cool.

https://www.youtube.com/watch?v=O201l4ci3Rs

however, i dont want to have the bricks explode on me and what not. Which cement blocks should i buy? also, am i supposed to start the fire in the cooker or place the hot embers in it from a burn barrel?

thanks.

i am planning to make a cool cinder block smoker as well. just dont want things to blow up. haha

tahnks

[LT72884]

hmm, i was thinking, can t really explode?

[Pyrotech]

You could line it with fire brick or do a surface coat of refractory cement.

[seattlepitboss]

When guys make heat treating ovens or forges lined with castable refractory the (dry) refractory mix is mixed with water then rammed into place and let dry. Then low heat is applied for enough time to make sure no water is left to form steam at superheated temps.

I'm thinking cinder blocks are similar. If they aren't BONE DRY then any moisture will flash into steam which can cause blowouts etc. So if you're worried do a small fire and let it go for several hours until the inside is all warm and super-dry. Or use some other means of heating the inside slowly for a long time.

That ought to make cinderblocks safe. They still might crack if you use intense heat, though.

seattlepitboss

[LT72884]

Originally Posted by seattlepitboss

When guys make heat treating ovens or forges lined with castable refractory the (dry) refractory mix is mixed with water then rammed into place and let dry. Then low heat is applied for enough time to make sure no water is left to form steam at superheated temps.

I'm thinking cinder blocks are similar. If they aren't BONE DRY then any moisture will flash into steam which can cause blowouts etc. So if you're worried do a small fire and let it go for several hours until the inside is all warm and super-dry. Or use some other means of heating the inside slowly for a long time.

That ought to make cinderblocks safe. They still might crack if you use intense heat, though.

seattlepitboss

Thats what i was thinking, how much moister is left in the bricks will determine my safety. haha. I hope that the pizza oven will be worth it. i hope it can take at least 500 degrees of heat., ill just put a stone above the pizza to reflect the heat done, but then again, i have a weber kettle and a red sky grilling stone. i could keep that as the oven and then just make a smoker out of cinder blocks.

thanks

[Bludawg]

Cinder blocks are like sponges and retain moisture for quite a while. Pre heat with a small fire once they are hot to the touch on the outside then put the coals to it.

[Mahoney86]

I remember the first time I placed my charcoal chimney on my concrete sidewalk at about 4am.... Don't know how the neighbors never complained to me about that one haha

[Pyrotech]

Originally Posted by LT72884

Thats what i was thinking, how much moister is left in the bricks will determine my safety. haha. I hope that the pizza oven will be worth it. i hope it can take at least 500 degrees of heat., ill just put a stone above the pizza to reflect the heat done, but then again, i have a weber kettle and a red sky grilling stone. i could keep that as the oven and then just make a smoker out of cinder blocks.

thanks

I seen molten glass poured into plaster molds. but that required weeks to months (depending on the mold size) of curing in a kiln before pouring the glass.

Our shop floors where we had the furnace(s) had a 3" bed of pack sand and clay to prevent the concrete from spalling if metal spilled. its not alot of fun having concrete spall while holding 10+ pounds of molten metal at the end of a long set of tongs.

for a tempory use I might use blocks and just be careful about heating them to fast to hot. but long term, I would be worried about the block breaking up.