Do-All Plus Furnace Refractory cement behind an insert

[tkirk22]

I have some questionable mortar joints in my brick firebox and I want to patch them up before I install an insert. The label on the Do-All tub says that the mix "air sets" and "heat cures".

Will this stuff cure with just the heat coming off the rear of the insert or does it need the higher temperatures of a direct fire?

Kirk

 

[Shane]

Probably the direct fire. your insert likely has a convection chamber and the heat off of that will likely not cure the cement. If it's not cured properly it can become brittle and kind of powdery.

 

[tkirk22]

OK so let me change the question.

Let's assume this fireplace will never ever ever be used again as a standard fireplace. Let's also assume that there will be either a fireplace insert or wood stove connected to it. What's the best mortar to use between the bricks?

I'm assuming I can use something that's more standard because of the lower temperatures. Is that correct?

 

[Gooserider]

OK so let me change the question.

Let's assume this fireplace will never ever ever be used again as a standard fireplace. Let's also assume that there will be either a fireplace insert or wood stove connected to it. What's the best mortar to use between the bricks?

I'm assuming I can use something that's more standard because of the lower temperatures. Is that correct?

I would probably just use a standard masonry mortar mix, just like in any other sort of masonry... It is worth noting that even though code on fireplace construction technically calls for refractory cement in the firebox joints, it is not unusual to see them built with standard masonry cement, seemingly without major ill effects.

Gooserider