dome questions

[waynebergman]

Having a good time here with the build so far. Got a few questions though.
Not wanting to angle cut all my bricks so mortor joints would be less than a quarter of an inch I shopped for special mortor made for thick joints. It is called molditX hear in Cananda. It is also rebaged into smaller quantities and renamed as devils putty. The devils putty is marked up 400percent so I would sugest to stay away from the small quantity purchase. I found this out from the guy at the warehouse who rebags it. My question is this.
My mortor is quite course so I am finding it dificult to have the close fit on the horizontal joints. I have to scape back the mortor half and inch away from the brick to brick joint because of the coursness of this mortor. However I feel this is the right mortor to accomodate the big thickness of mortor joint needed at the back edge of brick making the wedge to lift up the brick to the needed angle. Anyone else had similar frustrations? Maybee I should leave a 1/8th inch gap at the inside horizontal joint insteat of going for the brick to brick fit? If I dont scrape back the mortor from the edge a half and inch or so the agragate in the mortor it is so course (1/16" or so) that the bricks would have a minimum of about 1/16" gap and I am trying to get the bricks to touch but maybee its not worth doing. If I have this type of mortor and some big spaces at the outside edges perhaps I should just go with an eigth of an inch or so on the joints that will show on the inside of the oven?.....wayne bergman

[Les]

Wayne,

Your work is looking great! Your mortar shouldn't be that coarse to cause a problem. I have been mixing the forno bravo recipe, and then used heat stop tonight on the dome. Both have been very forgiving in their application. I suggest that you use shims and a grout bag and not rely on the mixture of mortar to support the brick. Using the bag and shims, allows you to position every brick where you want it to be.

I laid my first course tonight and had the same question. I am ending up with a maximum gap of 1/8 inch. Does it really matter. I am of a mind that if it's sealed at the back end - what harm can occur?

Sorry to tread on your thread, but they are somewhat related.

Good luck with your build,

Les...

[maver]

Go with the close brick joints and scrape back the mortar enough to allow this. A small gap of mortar behind the joint will be less of a concern than gaps between bricks. Paper beats rock, firebrick beats mortar.

I agree with Les, great brickwork!

Marc

[Les]

Maver - What harm will a small gap between joints do? I look at my wood stove, no mortar, been using it for 17 years for about 150 days a year. I can see a bit of wear on the bricks, but most of that has been cause by throwing wood at them.

Do you think that a 1/8 inch gap in the oven should be mortared? Just trying to clarify...

Les...