Oven Dome Mortar Mix?

[EricU]

I will be starting my 42" diameter WFO dome (I have a lot of pics posted in the thread My Build (Started in Napa, WFO dome & slab questions)) and I need some clarification on the mortar mix to use for the fire bricks that make up the dome.

Is the following mix the one to use?

1 part portland
3 parts sand
1 part lime
1 part fire clay

And for the sand, can I use the standard plaster sand that I normally use for masonary work?



Thank you, Eric.

[EricU]

Or should I use "Heat Stop"?

I could not find the link to the FB product? and wouldnt the shipping on a 50# bag kill?

Thanks again, Eric.

[nissanneill]

Hi Eric,
I would use (as I did on my 40" Pompeii build) brickie sand rather than plastering/rendering sand. I believe this is a little more 'fatty' than plaster and.
I personally would not use the refractory cement as I have not been impressed by the many postings in this forum reporting considerable cracking when using it when (please correct me if I'm mistaken folks), but I haven't seen one report of cracks when using the 'poor man's mortar mix.

Cheers.

Neill

[dmun]

As to the question of sand, it's reported that really fine sand makes a difference when mortaring our narrow joints.

[EricU]

So where does one get the finer sand? When I do masonary work, I just go to the yard and ask for "plaster sand"?

Thanks for the help, I really dont think I would have done this project without this forum and your guys help.

Eric.

[dmun]

It's sometimes called "silica sand" and it's sold in various meshes for abrasive finishing, or sandblasting.

[EricU]

Originally Posted by dmun

It's sometimes called "silica sand" and it's sold in various meshes for abrasive finishing, or sandblasting.

But Where do I get this finer sand?

Thanks, Eric.

[fxpose]

Originally Posted by EricU

But Where do I get this finer sand?

I picked up a 100lb bag of silica sand at Home Depot.

George

[Tscarborough]

Plaster sand, AKA Torpedo sand, AKA concrete sand, AKA setting sand has too big of aggregate allowed (up to 1/4"). Since the goal is 1/16th joints (but the reality is <3/8"), any fine sand will work. Masonry sand, play sand, sugar sand, finer grade blasting sands, but NOT All Purpose sand.

[EricU]

Originally Posted by fxpose

I picked up a 100lb bag of silica sand at Home Depot.

George

Home Depot I have heard of! As a matter of fact I have my own parking spot and they all yell "ERIC" when I walk in!


Thanks for the lead, Eric.