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-   -   will bricks w/side cut make my oven last longer? (http://www.fornobravo.com/forum/f8/will-bricks-w-side-cut-make-19838.html)

jimkramer 08-26-2013 07:23 AM

will bricks w/side cut make my oven last longer?
 
On my 5th course I decided to try making cuts on the side of the brick. I figured they'd be less likely to fall out than a straight cut. I made four bricks with 5 degree side cuts, placed them side by side dry, they looked good, so I cut the whole course that way. Turns out they don't really fit right - big gap on the inside of the oven (1/4-/12" in a few places), whereas the straight bricks fit nice and tight on the inside.

Will the side-cut bricks actually stay in longer? I don't care about aesthetics of tight fitting bricks. It's taking me MUCH longer to cut and place them, not sure if it's worth it. I could experiment to get the angle right, maybe a 4 degree (as the gap on the inside has been wider than the outside with 5 degree cuts).

Only problem is I'm doing most of this at night, can run the saw too much or the kids will wake up, and the neighbors will hate me.

mrchipster 08-26-2013 07:39 AM

Re: will bricks w/side cut make my oven last longer?
 
Sounds to me as if you cut to much off the interior edges of the bricks. The primary reason to cut the sides of the bricks is to counteract the inverted v gap that develops as you get higher up on the dome. You will also want to reduce the width of the bricks as you go higher.

Post some pictures if you can please.

Toomulla 08-26-2013 03:39 PM

Re: will bricks w/side cut make my oven last longer?
 
I used tapered bricks and cut the sides. As the angle in the arch/circle remains constant you can achieve tight even joints. I managed an average joint of 2-3mm. Whether this makes any difference in the long run I don't know I am just pedantic.

jimkramer 08-26-2013 07:04 PM

Re: will bricks w/side cut make my oven last longer?
 
1 Attachment(s)
Pic of my big joints...

Les 08-26-2013 08:11 PM

Re: will bricks w/side cut make my oven last longer?
 
I don't think it will add any life to the oven. I tapered mine and didn't use mortar - I would think that is worse case in regard to spalling. After years of use I see no sign of a problem.

Toomulla 08-26-2013 10:54 PM

Re: will bricks w/side cut make my oven last longer?
 
Has anyone actually had bricks fall out ?

brickie in oz 08-27-2013 01:17 AM

Re: will bricks w/side cut make my oven last longer?
 
Quote:

Originally Posted by jimkramer (Post 160351)
big gap on the inside of the oven (1/4-/12" in a few places), whereas the straight bricks fit nice and tight on the inside.

12mm is way too much of a mortar joint on the inside, 6mm is also pushing it, the tighter the bricks on the inside the better, bricks touching with no mortar is even better. :)

(12" is way way too much)........ :eek: :p :D

oasiscdm 08-27-2013 03:28 AM

Re: will bricks w/side cut make my oven last longer?
 
Quote:

Originally Posted by Toomulla (Post 160406)
Has anyone actually had bricks fall out ?

I'm guessing with large joints and heating and cooling cycles it is possible. Reminds me of a comment les made about his bricks finding their own happy place. But his dome is a work of art.

rsandler 08-27-2013 06:42 AM

Re: will bricks w/side cut make my oven last longer?
 
Quote:

Originally Posted by Toomulla (Post 160406)
Has anyone actually had bricks fall out ?

People have definitely had un-tapered bricks from their entry arch slip out. I remember last year or so someone asking for help because that happened.

My thinking in my build was to ask "if the mortar fails to bond or crumbles to dust because I'm an idiot at masonry, what's holding this brick in?" If the bricks are angled on the side (that is, inside face smaller than outside face), there's really nowhere for the brick to go, ever, at least if the inside faces are touching. Magic of physics, that. If the inside faces aren't touching, and the bricks aren't beveled, then theoretically a brick could slip. Making a bevel cut (top face smaller than bottom bace) increases the amount of surface area that's touching, but the main thing is it avoids large triangles of mortar.

Toomulla 08-27-2013 07:12 PM

Re: will bricks w/side cut make my oven last longer?
 
Thanks for the reply I used tapered bricks and then cut the sides to the required taper , and touched up any with the 4 inch grinder and a diamond wheel I generally achieved 2-3 mm joints I did this on the same idea your laid out but wondered if I was just being pedantic. The final crown had nine bricks and took em 9 hours so I am probably still nuts.

I established the actual diameter of the oven by setting a full circle or tapered bricks with a 2mm joint spacer - generally happy with the result


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