firebrick 'dust, sludge' reuse?

[victorsee]

I am now on my third round of firebrick for a 42" outdoor oven on Martha's Vineyard. Using a wet saw to cut brick, and have collected a goodly amount of 'clay sludge' that I clean out and save after every use of the saw. Two questions for all the experts out there...
1. does it make sense to use that brick sludge to fill small spaces between bricks on the oven floor?
2. Does it make sense to mix that sludge with refractory cement ( its expensive stuff!) and use it to fill exterior spaces between bricks forming dome?

Thanks in advance.. for your thoughts!

[azpizzanut]

Hello,

I rinsed the debris from my saw tray onto the lawn. The grass seems greener under that spot now. Others believe that the sludge can be saved and used as an adjunct for mortar. I'm not sure of the proportions they might use with clay, Portland cement and lime. etc. I don't recall seeing a recommended recipe for that.

As to your question about filling spaces between dome bricks, were you going to combine mortar with the sludge and fill exterior spaces of the dome? Would your custom mix be as sound as the mortar used to place the bricks?

The best material to fill spaces between hearth bricks is wood ash. Why fill spaces in the hearth with something that might possibly work its way up and contaminate pizza crust? Ouch !! If wood ash gets on cooked food you can hardly notice.

Cheers,

[Lburou]

Yes to both questions....That is what I did with no regrets. Gravity pulls down on the stuff between the bricks 24 hours a day

[victorsee]

Lee and Bob..
thanks for your input.. both perspectives make sense... I hope you are enjoying your ovens.. and I look forward to the same with mine, shortly!

[Poops]

Hi

I spoke with a manufacturer of firebricks in Adelaide for my build, and was told that fireclay (the powdered stuff mixed with brick sand, lime and cement to make mortar) is what firebricks start off as so no problems using it over.
I also read somewhere that firebrick offcuts can be smashed up with a hammer (safety glasses on) and used for the same purpose. Perhaps a job for the kids if you have them ...

Best of luck.

[victorsee]

Thanks that makes a lot of sense.
this is an amazing site, thinking that we are sharing 'building notes' between both ends of this funny planet!