Go Back   Forno Bravo Forum: The Wood-Fired Oven Community > Pizza Oven Design and Installation > Finding Building Materials

Like Tree1Likes
  • 1 Post By Mistertoy

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 08-04-2012, 04:24 PM
Laborer
 
Join Date: Jun 2012
Location: London, UK
Posts: 90
Default Mortar for the Dome? (& insulation?)

Starting to think about the internal dome...

I found a supplier for the fire bricks, and for the fb board (and maybe even the blanket) that said, I'm not sure what I should be mortaring the fire bricks with.

Should I be using fire clay, fire mortar, fire cement etc? There are so many options! Can someone provide some clarity?

Also - for the insulating blanket, how many meters have people used for a 42" dome?

Finally - I'm guesstimating about 180 bricks for the dome... does this sound right? And how much fire mortar/cement/clay should I be looking at buying?

M.
Reply With Quote
  #2  
Old 08-04-2012, 06:27 PM
Les's Avatar
Les Les is offline
Il Pizzaiolo
 
Join Date: Sep 2005
Location: Carson City, NV
Posts: 2,851
Default Re: Mortar for the Dome? (& insulation?)

I went through 277 brick for my 42 inch. I did have a lot of scrap. In regard to the mortar, the home brew works well and it's a LOT less expensive than the mortar that you would buy.
__________________
Check out my pictures here:

To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


If at first you don't succeed... Skydiving isn't for you.
Reply With Quote
  #3  
Old 08-05-2012, 05:20 PM
Laborer
 
Join Date: Sep 2009
Location: Harrisonburg, Virginia
Posts: 62
Default Re: Mortar for the Dome? (& insulation?)

I am using the home brew mortar right now. Although I can not compare it with a name brand refractory mortar, I have never used one, it seems to be holding up well. It is very easy to use and was way cheaper than anythig else.

I have used about 180 bricks so far and I am building a 42" making only side bevel cuts to reduce the inverted V. I trashed or experimented, with the home brew, about 5 full bricks so I guess I actually only used about 175 bricks.


David
__________________
"Leave the gun. Take the cannoli." - Peter Clemenza
Reply With Quote
  #4  
Old 08-06-2012, 08:45 AM
Laborer
 
Join Date: Jun 2012
Location: London, UK
Posts: 90
Default Re: Mortar for the Dome? (& insulation?)

Thanks

Regarding the mortar... I'm umming and arring about what to use! Homebrew sounds like the plan, but I need to find a calcium aluminate supplier in the UK - which isn't proving easy!

m.
Reply With Quote
  #5  
Old 08-06-2012, 01:33 PM
david s's Avatar
Il Pizzaiolo
 
Join Date: Mar 2007
Location: Townsville, Nth Queensland,Australia
Posts: 4,824
Default Re: Mortar for the Dome? (& insulation?)

The home brew doesn't use calcium aluminate cement. The difficulty with using calcium aluminate is that is goes off really fast, therefore requiring mixing small batches all the time. It is also expensive stuff. The home brew using 3 parts sand, 1 part Portland cement, 1part fireclay and 1part lime is so much easier, cheaper and does the job perfectly adequately. If using calcium aluminate cement and lime you will find that the lime acts as an accelerant and the stuff goes off even faster. When combining Portland and lime though, the lime acts the opposite and makes the mix go off slower.
Reply With Quote
  #6  
Old 08-06-2012, 01:49 PM
Laborer
 
Join Date: Jun 2012
Location: London, UK
Posts: 90
Default Re: Mortar for the Dome? (& insulation?)

I was planning on a 3:2:1 mix (3 parts sand, 2 parts fire clay, 1 part calcium alu - no lime). It should conduct heat better than portland, thus acting as a thermal heatsink rather than an insulator...
Reply With Quote
  #7  
Old 08-06-2012, 02:29 PM
david s's Avatar
Il Pizzaiolo
 
Join Date: Mar 2007
Location: Townsville, Nth Queensland,Australia
Posts: 4,824
Default Re: Mortar for the Dome? (& insulation?)

I can't really see why, there would be little difference in the density of two mixes. It would be marginal at best. My feeling is that the lime and Portland brew is better because of its better workability and it's way cheaper.
Reply With Quote
  #8  
Old 08-07-2012, 01:36 AM
Laborer
 
Join Date: Jun 2012
Location: London, UK
Posts: 90
Default Re: Mortar for the Dome? (& insulation?)

Quote:
Originally Posted by david s View Post
I can't really see why, there would be little difference in the density of two mixes. It would be marginal at best. My feeling is that the lime and Portland brew is better because of its better workability and it's way cheaper.
It's not about density... it's about alumina content... HAC as it's known in the UK (High Alumina Cement) can have up to 93% or so alumina, which makes it great for refractory mortar...

The downside (debateably) is that it sets quickly without a retardant...

M
Reply With Quote
  #9  
Old 08-07-2012, 02:25 AM
david s's Avatar
Il Pizzaiolo
 
Join Date: Mar 2007
Location: Townsville, Nth Queensland,Australia
Posts: 4,824
Default Re: Mortar for the Dome? (& insulation?)

Quote:
Originally Posted by Spinal View Post
It's not about density... it's about alumina content... HAC as it's known in the UK (High Alumina Cement) can have up to 93% or so alumina, which makes it great for refractory mortar...

The downside (debateably) is that it sets quickly without a retardant...

M
The cement content is only about 15% so any advantage would be severely diluted by the numbers.
Reply With Quote
  #10  
Old 08-07-2012, 06:17 AM
Laborer
 
Join Date: May 2011
Location: Brisbane Australia
Posts: 62
Default Re: Mortar for the Dome? (& insulation?)

Quote:
Originally Posted by Spinal View Post
I was planning on a 3:2:1 mix (3 parts sand, 2 parts fire clay, 1 part calcium alu - no lime). It should conduct heat better than portland, thus acting as a thermal heatsink rather than an insulator...
If you are set on using calcium aluminate then I would not use 2 parts fireclay. I used calcium aluminate and did a number of trial batches to get the feel of different proportions, how it worked and fast it set. You do need to make small batches and when it is hot is really does go off quickly. I would suggest 3 sand, 1 fireclay and 1 calcium aluminate. I used similar but replaced 1 of the sand with finely crushed firebrick (grog) but this did made the mix harder to work with.

Brett
Spinal likes this.
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
Dome on top of floor - mortar dome to floor? Cheesesteak Pompeii Oven Construction 3 04-29-2011 07:11 AM
Why slather mortar on the outside of the dome ThermoJax Newbie Forum 16 07-29-2010 10:02 AM
Drilling shallow mortar pockets into bricks kebwi Tools, Tips and Techniques 12 09-14-2009 11:27 AM
Cleaning Mortar from Dome Question PizzaJNKY Getting Started 12 12-15-2008 01:13 PM
Coating the outside of the dome prior to insulation George T Pompeii Oven Construction 5 07-19-2008 02:45 PM


All times are GMT -7. The time now is 10:27 AM.

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