Refractory Mortar Query

[stonetrader]

I have just joined this forum to get some advice and ideas on building a 42inch Pompeii oven and have already learnt so much.
I .live in Perth Western Australia and am finding it very hard to get some advice on refractory mortars.
The advice that the suppliers here give is that the refractory mortar can only be applied 5 or 6 millimetres thick and if it is applied any thicker it will crack and fall out.
Can anyone give me some advise on that or would I be better off mixing my own mortar using portland cement lime fireclay and sand,as I have seen mentioned in this forum.
Any advise would be much appreciated

[deano]

Re: Refractory Mortar Query

I would think you could add a coarser aggregate like fireclay or sand to the refractory mortar to allow a larger joint.

[mewsy]

Re: Refractory Mortar Query

I'm in Perth and have built 2 ovens now, and just starting my third - email me and I will give you a list of suppliers and some pics if you like

Garry

[Neil2]

Re: Refractory Mortar Query

"I would think you could add a coarser aggregate like fireclay or sand to the refractory mortar to allow a larger joint."

Deano is right. For the joints wider than 5 to 6 mm, you can "entend" the mortar with masonry sand, mix 1:1 with the mortar. Beyond about 12 to 15 mm, best to fill with some firebrick shims.