#1  
Old 05-03-2014, 06:42 PM
Yannick's Avatar
Laborer
 
Join Date: Mar 2014
Location: Gloucester, VA
Posts: 70
Question Cementing the bricks question

Do you cement the bricks like regular clay bricks (mudding the edges of the brick) or like a ceramic tile? (even coat and use a notched trowel)
Reply With Quote
  #2  
Old 05-03-2014, 06:50 PM
Apprentice
 
Join Date: Apr 2014
Location: South Carolina
Posts: 126
Default Re: Cementing the bricks question

Quote:
Originally Posted by Yannick View Post
Do you cement the bricks like regular clay bricks (mudding the edges of the brick) or like a ceramic tile? (even coat and use a notched trowel)
I use a regular trowel, not sure what the pros use. I just mortared my first brick a little over a week ago.
Reply With Quote
  #3  
Old 05-04-2014, 03:42 AM
cobblerdave's Avatar
Il Pizzaiolo
 
Join Date: Jan 2010
Location: brisbane australia
Posts: 2,339
Default Re: Cementing the bricks question

G'day
Now that's an interesting question I read it earlier and had a big think about it.
What you want to achieve is near brick to brick contact on the inside face of the oven. That's why folk take so much time and effort in cutting and positioning there bricks.
Now if you are leaving the bricks uncut on the bottom and the top, you have a larger gape at the outside. Of course a trowel ( and spacing wedges) are what you would use.
With bricks cut side and bottom and top using a notched flat trowel like tiling would over some advantages. Anyone that has done some tiling knows that those gapes left by the notched trowel allows you to position the tile by being able push it into the mortar bed to get it perfectly level and aligned.
You would certainly be able to push your bricks together at the front face to get that brick to brick contact.
But as you pointed out are those spaces between the mortar further to the back of the tile going to somehow weaken it?
My opinion on this is that it doesn't. The strength of the dome comes about from that inside contact. As some as that last brick goes in the dome is strong due to gravity bearing down on it rather than being stronger than the gravitational forces on it.
In saying that there are more than gravity acting on any oven. You heat these things up then let them cool. There is something to be said for the mortar being a flexibly union between the individual units (bricks)
The hydrated lime in the homebrew gives a flexible union. Its been used for centuries, no thousands of years for mortar, long before Portland came along. A lot of the roman structures are still standing regardless of gravity or time!
Anyway those are my thoughts on that. I hope someone can add to this as I'm keeping an open mind on this.
Regards dave
__________________
Measure twice
Cut once
Fit in position with largest hammer

My Build

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

My Door

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

Last edited by cobblerdave; 05-04-2014 at 03:45 AM. Reason: Speeling
Reply With Quote
  #4  
Old 05-04-2014, 08:43 PM
Greenman's Avatar
Master Builder
 
Join Date: Feb 2013
Location: Bundaberg. Australia
Posts: 737
Default Re: Cementing the bricks question

On the dome bricks I just buttered the two edges that were about to touch the build and wriggle it a little as it comes into contact to position it. When I had completed the course/chain I removed the wedges and filled any voids. Not sure if there is a right or wrong way but that worked for me.

I did not cut my bricks to get the 'stand alone perfect fit' though and it might need a different technique if all of the faces meet tight.

I just used a small(ish) pointed trowel.
__________________
Cheers ......... Steve
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.


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


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


Forno Food Pics
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #5  
Old 05-10-2014, 05:55 PM
ogorir's Avatar
Laborer
 
Join Date: Aug 2013
Location: Waco, Tx
Posts: 60
Default Re: Cementing the bricks question

I only cut the vertical sides of my bricks (bevel and wedge). I used a full size brick trowel and laid a mortar bed on the previous course, buttered the vertical mating surface of the brick I was setting, set in place, then pulled out as much mortar from the outside as I could with my finger. I found the bricks set way faster this way with the homebrew mortar (4:1:1:1). I used the extra mortar each night to fill in the wedges of previous courses. By placing the bed on the existing bricks, I could taper the mud so I didn't have to squeeze as much out on the inside to get a nice tight joint.

I also used a sponge. a lot. to clean up mortar.
__________________
Time flies like an arrow; Fruit Flies like a banana.

My oven (thus far):
To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #6  
Old 05-11-2014, 03:25 PM
Master Builder
 
Join Date: May 2011
Location: South Australia
Posts: 558
Default Re: Cementing the bricks question

I use a paint scraper, I butter the vertical side of the preceding brick and the top of the bricks below and set my brick in place with the IT. Tap things gently and the mortar squeezes out all round. Scrape off excess with the paint scraper and on to the next brick.
I only mix enough mortar for about 4 or 5 bricks, so I can mix it quite "stiff".
End result is the bricks stay in place without wedges and things.
Wedges of brick should be removed before the mortar sets, or they might prevent the bricks following the mortar as it shrinks slightly, creating dryiong cracks.
Reply With Quote
  #7  
Old 06-03-2014, 11:03 AM
Yannick's Avatar
Laborer
 
Join Date: Mar 2014
Location: Gloucester, VA
Posts: 70
Default Re: Cementing the bricks question

I've been using a 2" paint scraper myself. I butter the perimeter of the brick that I install. I'ts been working fine so far.
Reply With Quote
  #8  
Old 06-03-2014, 02:46 PM
Novaslo's Avatar
Apprentice
 
Join Date: Dec 2013
Location: Paso Robles
Posts: 155
Default Re: Cementing the bricks question

I struggled with mortaring my first row even after soaking the bricks. The mortar from Forno Bravo is drying quickly or at least leaching water enough that it is hard to move a brick without breaking bricks around it or breaking the mortar seal you just made on the one next to it.

Here is what I resorted to.
I bought a Mortar Grout Bag from Amazon 7.99

This allowed me to squirt the mortar into place and really worked well.
You have a bit of a wetter mix but the brick is sucking up water so quickly that I don't think it is an issue.

As you run out of mortar, I would simply mix it right in the bag. The mortar bag is big. Put in more mortar, add some water, Shake back and forth pinching the ends. Viola, mix ready to go.

This has been a game changer for me. I am also getting more mortar in the crevices where before, I was struggling.

Still use the wedges to keep the bricks that you need to mortar in place. Squeeze in mortar push it in the best you can. Wait a few minutes and pull the wedges. Fill the void. done.

Good luck.
__________________
Darin

I often cook with wine, sometimes I even add it to the food...
WC Fields


Link to my build


To view links or images in signatures your post count must be 0 or greater. You currently have 0 posts.
Reply With Quote
  #9  
Old 06-03-2014, 04:26 PM
Master Builder
 
Join Date: May 2011
Location: South Australia
Posts: 558
Default Re: Cementing the bricks question

Quote:
Originally Posted by ogorir View Post
I found the bricks set way faster this way with the homebrew mortar (4:1:1:1).
How have you found the longevity of the 4:1:1:1 mortar?
The FB recipe is 3:1:1:1, but plenty of masons and experienced cement professionals on this site have stated that 3:1:1:1 is way stronger than mortar used for laying brick walls, etc.
In an oven, it is probably good that the mortar is just as strong as the bricks - unlike a wall where we want the mortar to break before the brick does.

However, the downside of the extra strength is that the mortar has less adhesion to the brick. i.e. every pro, and everything I can find to read, will tell you that the adhesion to the brick is inversely proportional to the strength.

With that in mind I've been considering making the mortar for the next oven a little weaker, because it seems to me that most cracks seem to be the mortar pulling away from the surface of a brick. 4:1:1:1 sounds good.
Any problems encountered?
Reply With Quote
  #10  
Old 06-03-2014, 06:00 PM
Tscarborough's Avatar
Il Pizzaiolo
 
Join Date: Oct 2009
Location: Ausitn
Posts: 3,075
Default Re: Cementing the bricks question

The correct and proper ratio is 2-3 parts aggregate to the cementious parts of the mix, by volume. This is not new or experimental, Vesuvious laid it down as a rule back in the time of the Roman empire. In the case of homebrew, that makes the correct proportion (Portland/lime/fireclay/sand): 1/1/1/6-9. The stronger it is, the less bond strength, the more shrinkage cracking, and the less work time you will have with the mortar, just less workability overall.

This is a common mistake made, and one that does not really hurt anything, other than make laying up the structure harder than it has to be. Use the correct proportions, wet, not soak the bricks in high temps/high winds, and you do not have to mix small amounts every 10 minutes, plus you will have less cracking in the finished build. It is MORTAR, not CONCRETE.
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
Fire bricks Nick in Laval Pompeii Oven Construction 3 10-30-2012 11:24 AM
So will there be a discourse on tapering bricks? skoolpsyk Tools, Tips and Techniques 8 08-22-2011 05:28 PM
Do I have the right bricks? Dolf Newbie Forum 7 01-22-2010 10:35 AM
Just got 3 tons of bricks... phoenixzorn Getting Started 0 10-21-2007 07:18 PM
FB Materials List Hendo Getting Started 21 03-09-2007 01:28 AM


All times are GMT -7. The time now is 10:42 PM.

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