Reclaimed brick project...

[drinkswellwithothers]

Greetings...
My wife and I have taken the leap of faith into the WFO arena. We've lurked around the edges of this site long enough, gathering ideas and 'I wish I would haves' to incorporate into our project. We feel like know some of you fairly well just from reading your posts.

Anyway...

Geneva Steel (Orem, Utah) was selling off unused, high-temp fire brick for $.50 a piece. We went to the site and were like kids on a treasure hunt. We found all kinds of pre-cut, angled brick of all different sizes. We ended up limiting our take to the standard sized 4.5" X 9" bricks and tapered 9" bricks for the barrel roof. We found, what we call a 'jail brick', to use over the ash dump, and some other various sizes (their use still to be determined).

It's nice to be a registered user finally and to be able to take advantage of all that there is here.

We've just completed the barrel vault using the tapered bricks, which are 2.75" thick. Wondering if we need to add another layer of bricks, concrete or fire clay to increase the thermal mass before covering with thermal blanket.

Any thoughts/experiences would be appreciated.

Cheers...

[yorkshireknight]

Re: Reclaimed brick project...

Hi Guys, Let me first congratulate you on your build thus far.
I notice no one yet has replied to your pondery and I, having only just finished my build wish to try and assist with my two penneth.

I am by no means an expert on thermal mass but here are my thoughts on the matter.

If you were to buy a ready to go WFO from a supplier the thickness of the dome wouldn't be as thick as you have now, so surely a 2.75'' must be ok to use.

adding more thermal mass means longer to heat up and more fuel to saturate the dome BUT means the heat given off will last longer.

Dependant on how you wish to use your oven would then dictate if you really, really required extra mass.
In simple terms (because I am) if standard bricks were 5.5'' long Im sure most of us would have ovens of 2.75 deep.
If it were me I would insulate over what you have because I don't believe it will be a problem.
Having now said that I'm sure you will now receive more replies if anyone disagrees with my theory.

[stonecutter]

Re: Reclaimed brick project...

We've just completed the barrel vault using the tapered bricks, which are 2.75" thick. Wondering if we need to add another layer of bricks, concrete or fire clay to increase the thermal mass before covering with thermal blanket.

Any thoughts/experiences would be appreciated.

Cheers...

Hmmm...this one slipped through the cracks.

These brick came from a steel mill? They are most likely high duty, so thermal conductivity will be high too, I don't think you want to add anymore mass than a reinforced cladding ( 1/2"-1" ) over your dome, since there are a series of arches that are are not bonded...just a bit of added structural insurance.

But the issue I see ( or how it appears in the pictures ) is that you have no insulation under your floor. If this is true, what you have there is a big heat sink, and the concrete slab will suck the heat out of your brick..which will create unbalanced heating inside the oven. In fact, every bit of uninsulated mass that touches thermal mass, will draw heat.

Bottom line, the oven will perform poorly....if you choose not to fix this now, be prepared for very,very long firings and a temperamental oven.

[stonecutter]

Re: Reclaimed brick project...

Yikes...just noticed the date on the original post.