For mortaring the dome bricks, I have been advised that regular refractory is not as good as castable due to the larger gap at the back (top) of the brick where the wedge goes in. I have got 3 different opinions and all differ so I may as well ask those that have built one and hopefully know. Which is best please !
Announcement
Collapse
No announcement yet.
Castable or regular Refractory ?
Collapse
X
-
So, I'm assuming that you're asking about calcium-aluminate cement (CAC) based products, as opposed to something with portland cement like the widely used 3:1:1:1 homebrew. My understanding is that it is the case that many commercial CAC mortars of that nature are designed for small joints (like 1/16"), so strictly speaking aren't ideal for building a brick oven. That said, people use it anyway and their ovens generally stay up (don't get the pre-mixed stuff in a tub, though, that stuff isn't right for this application). I don't think I've ever seen anyone on this forum using a proprietary refractory castable as a mortar. Depending on the product, it may have things like fibers that would be great in a cast structure but would make it hard to work with as a mortar.
Personally, I built both my ovens using 3:1:1:1 homebrew (3 parts sand, 1 part portland cement, 1 part hydrated lime, 1 part fireclay, by volume), and would not bother with CAC proprietary refractory mixes if I made another.
Comment