#11  
Old 05-14-2009, 03:52 AM
Serf
 
Join Date: Apr 2009
Location: adelaide
Posts: 6
Default Re: High duty fire bricks

I purchased several pallets of high duty fire bricks cheap. I have decided to use them on the hearth only. My reasoning is that they will tend to get hot and stay hot- this would seem to be an advantage. How many people have posted on this forum complaining that the hearth is not hot enough to cook their pizza bases? (possibly a technique peoblem).
I also remember seeing in Alan Scotts book a comment that high duty bricks were good for the hearth (I think). I also saw a post on another forum about 5 years ago from Canada. This oven builder owned a foundry and built his entire oven from high duty fire bricks. He said he had no problems.

I am in the middle of the build. I will let you know how I go.
Reply With Quote
  #12  
Old 05-14-2009, 04:34 PM
Journeyman
 
Join Date: Jun 2008
Location: Melbourne Australia
Posts: 399
Default Re: High duty fire bricks

Low duty refractory bricks are usually in the 18-26% AL203 grade with med. duty about 26-45, and superduty 45% and up. Density usually increases as alumina content increases. Most firebricks are dry pressed, but you can get extruded/ wirecut poor quality product. We sell 40% grade f/bricks to the general public for their WFO's.
Reply With Quote
  #13  
Old 12-12-2009, 06:21 PM
Abear's Avatar
Peasant
 
Join Date: Apr 2009
Location: Tomball, Tx
Posts: 32
Default Re: High duty fire bricks

I've finally finished our oven with medium duty bricks (40% alumina content) and I can honestly say I'm quite pleased with the bricks. It takes about 1.5-2.0 hours to get about 850-900 degrees on the dome and 650-700 on the hearth. After a round of pizzas, we've done oven-dried tomatoes and brisket overnight with fantastic results! At 12PM the next day, the walls are still reading 250 degrees. I wouldn't be worried about using medium duty bricks - if they're cheap, use them!
Attached Thumbnails
High duty fire bricks-our-first-pizza-.jpg  
Reply With Quote
  #14  
Old 12-13-2009, 04:49 PM
Neil2's Avatar
Il Pizzaiolo
 
Join Date: Oct 2006
Location: Vancouver Island
Posts: 1,374
Default Re: High duty fire bricks

I suspect, that for pizza and bread ovens, there is no practical difference in heat up time or heat retention between "high duty" and "low duty" firebricks.
Reply With Quote
  #15  
Old 12-28-2009, 12:16 PM
Serf
 
Join Date: Aug 2008
Location: Virginia
Posts: 2
Default Re: High duty fire bricks

Where can I get BF Varnon Slabs
Reply With Quote
  #16  
Old 12-28-2009, 01:03 PM
Journeyman
 
Join Date: Jun 2008
Location: Melbourne Australia
Posts: 399
Default Re: High duty fire bricks

I think Varnon are made by AP Green?
Reply With Quote
  #17  
Old 12-29-2009, 08:18 AM
fornax hominus's Avatar
Laborer
 
Join Date: May 2009
Location: ottawa valley canada
Posts: 95
Default Re: High duty fire bricks

I built my oven with a combination of med and hi-duty bricks .. all salvaged and some vintage from steamship boilers.. I did come across some ''chief'' #1 arch bricks which I used on row 6 , they are the last bricks to lose their soot as they have more mass the further they go into the dome , and I mortared them in . After parging with mortar I put a layer of extreme heavy duty aluminum foil [shiny side in ] over the whole oven , before the ceramic fiber layer. I also have a floor of 3x5x7in. hi dutys and they do hold their heat!!
One aspect that hasn't been mentioned so far is that hi-dutys weigh more! so they have to take longer to heat up , and longer to cool .
I am tossing a handful of snow in these days to add moisture for the bread.. it vapourizes fast!!
Reply With Quote
  #18  
Old 12-29-2009, 08:20 AM
fornax hominus's Avatar
Laborer
 
Join Date: May 2009
Location: ottawa valley canada
Posts: 95
Default Re: High duty fire bricks

Quote:
Originally Posted by Johnny the oven man View Post
I think Varnon are made by AP Green?
I may be wrong [what? Again?] but I think AP green is no longer with us.
tim
Reply With Quote
  #19  
Old 12-29-2009, 11:18 AM
dmun's Avatar
Moderator
 
Join Date: Jul 2005
Location: New Jersey USA
Posts: 4,216
Default Re: High duty fire bricks

There was a big consolidation of the refractory industry a few years back, I think partly because of asbestos liabilities. I think AP green was absorbed into the Harbison-Walker refractory conglomerate. Now HW is about the only game in town in the US.
__________________
My geodesic oven project:
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
,
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #20  
Old 12-29-2009, 11:30 AM
fornax hominus's Avatar
Laborer
 
Join Date: May 2009
Location: ottawa valley canada
Posts: 95
Default Re: High duty fire bricks

Oh! Asbestos! ... great! I bought and am still using on my kiln a stash of AP Green's EPG50 insulating cement .. grey , fluffy and they claimed no asbestos... they claimed.. sigh!! .. Anybody heard a discouraging word on this?
tim
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Oven (Floor - Wall - Dome) Fire Bricks Thickness?! southpaw Pompeii Oven Construction 11 03-12-2011 10:54 AM
Firebrick - Low duty, High duty thecac Pompeii Oven Construction 9 02-12-2009 10:22 PM
New Fire Bricks with Cracks staestc Getting Started 8 11-03-2008 04:37 AM
Has anyone used high duty fire bricks? gecko Getting Started 11 07-27-2008 01:07 AM
fire bricks boccu Getting Started 8 12-10-2006 11:38 AM


All times are GMT -7. The time now is 11:12 AM.

Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
2006/10 Forno Bravo, LLC