How long to wait for decorotive arch to dry-cure?

[thebadger]

Gang,

I am in the process of curing - just small fires -300-350.

I need to install my outer decorative arch using regular housebrick and mortar which willbe put around my firebrick outer arch (much like ken did).

Question
How long should I wait between the letting the mortar dry and starting the curing again. The front arch hasn't been getting too hot (warm to the touch). Again, this is regular brick/mortar on the outside of my firebrick arch.

Thanks
Dick

[Ken524]

Re: How long to wait for decorotive arch to dry-cure?

How long should I wait between the letting the mortar dry and starting the curing again... Again, this is regular brick/mortar on the outside of my firebrick arch.

I have the same question.

I figured I would let the "decorative arch" mortar (Type S Mason Mix) cure for about a week. I want to make sure it's really set up hard. My arch is connected to the oven face by a few brick ties. I don't want the heat trying to pull the arch away from the wall before those ties are really locked in.

I would welcome any comments from the pros!!

[gjbingham]

Re: How long to wait for decorotive arch to dry-cure?

I posted before that the Black and Decker Masonry book states one week of cure for a circular ring of brick project. The arch seems to be half of that shape, so I'd give it a week.

If you precision cut the bricks with no mortar joints, I think you'd be safe pulling the forms after 2 -3 days, assuming the form was shimmed so that you could remove it without causing stresses upon removal.

[Les]

Re: How long to wait for decorotive arch to dry-cure?

This kind of begs a question. If you built your whole project using high heat mortar - why not continue with it? Thats my plan, even when I get past the insulation. It seems to work the same way, minus the lime (makes it a little more sticky). Cost wise, since I'm making my own, it may be even less expensive. In regard to cure time - that is a hugh variable. If it's just warm to the touch - I would think you are good to go after a day or two.

Ken - I have seen on this forum where the mortar has set for months and still cracked. People have diligently fired their ovens and have seen cracks - I don't recall who first phrased it - "cracks happen" (James - find the guy and give him a bag of flour )

If this helps - I pulled my forms on my arch about two days after. I do live in an environment where is is so dry it will suck the moister out of your hair.

Les...

[thebadger]

Re: How long to wait for decorotive arch to dry-cure?

Les,

Thanks.

I'm using HS50 and it's my understanding that you don't want it to get wet. My "decorative arch" on my igloo will be exposed to the elements 24/7. This arch, along with an outdoor is what I was planning on using to keep water from the Firebrick.

A week was what I was thinking.

dick

[christo]

Re: How long to wait for decorotive arch to dry-cure?

I took out my arch forms 2 days after forming and it cracked.

I tore it down and rebuilt - and added butressing as it also pushed the walls of my opening out as the cement failed....

I think a week is better!

[SpringJim]

Re: How long to wait for decorotive arch to dry-cure?

Any reason not to keep the decorative bricks wet while you cure the dome? Just drape a wet towel over the outside brickwork?

cheap insurance?

(and can anyone confirm that the refractory mortar should not get wet? You mean it can't be used for an exterior application....not that you don't keep is damp to let it cure, right?)