39 inch - 1000mm corner brick WFO build - Newcastle au

[Newie newby]

Just filled up the backs of the dome bricks tonight with a different mortar supplied with kit called "fondu mortar". Still high temp rated but supposed to be better for larger gaps. Mixed with washed brickies sand 1 part dry mortar to 3 parts sand, just enough water to make mortar like consistency when mixed. Much easier to fill the gaps than laying the bricks, especially when outside will be covered later anyway...

[david s]

The wet ready to go mortar in the bucket sounds like a sodium silicate based mortar. The “fondu mortar” sounds to me more like Ciment Fondu which is calcium aluminate cement, not a premixed mortar. It requires the addition of a fine aggregate to create a mortar and what you have described that you did by mixing the 3 parts washed sand to it. Because it reacts far faster than Portland cement there is no need for extended damp curing.