Flue mortar - solution for too wide mortar joints?

[thamnophis]

I came back from the brickyard with castable refractory cement to mortar my firebricks. It didn't look right - had aggregate in it. So I called the manufacturer and learned what I feared - no good for mortar joints.

After some conversation where they assured me the 50 pound buckets of pre-mixedrefractory mortar I had been using really weren't right for the job either. Refractory mortar shrinks, they explained.

Instead they suggested something they're selling as flue mortar - ALSEY Flue-Set Non-Water Soluble Refractory Mortar to be specific. They said it is harder to work with, but is good for filling larger voids, like untapered arch bricks, plus its OK exposed to the weather after 24 hours.

I'll buy a 50 pound bag (over $100!) but wondered if others have had experience with it?

[dmun]

There's a few references to the stuff here in the forum:

Google

Nothing like the hundreds of cites for the more common mortar choices.

[ThermoJax]

I can tell you that I purchased at least 3 50 pound buckets of premixed, and a bag of dry stuff, then switched to the homebrew recipe listed on this site, and was more satisfied with the home brew, and with what I have left over from the 20 bucks for the homebrew, I probably could build a whole extra oven. Spend the 20 bucks on the lime, type S portland cement, fine sand and firemortar. Mix it up and play with it. Easy to work with, and has a great track record here on this site. As I look back over time, I would guess that hundreds of builders of ovens here have used it, and years later still report great results. Speaks for itself.

Good Luck


Tom