Curing temperature for refractory mortar

[randomseeker]

I am about to receive my new Smoky Lake 2.5 x 8 evaporator. I will need to install the fire bricks and am wondering if there are any temperature constraints. I have a few days above freezing when I can cut and mortar the bricks, but then it goes below freezing again. What are my chances of getting a good set? If questionable, any suggestions? Thanks in advance.

[n8hutch]

I bricked my arch in the winter, I did however have heat. I think you will want to keep it around 50° F , a space heater might be a good option. Sometimes you can rent them pretty cheap if you don't have one.

Only thing I would Add is to try to offset the joints on your bricks, I forgot till I got 1/4th of the way through. Brain cramp.

[SeanD]

Because I'm always behind schedule, all my bricking, repair, and rebricking have been done in the winter. Just put a shop light or slamm space heater on the grates of the firebox and put a piece of plywood over the top of the evaporator and you'll be good. If you don;t have plywood, cardboard and something to weigh it down works just as well. Just check it once in a while to make sure the bulb did not go out.

Sean

[lpakiz]

I did something similiar. I put a 500 watt halogen shop light on the grates, a piece of plywood or Dowfoam insulation on top, in place of the pan. I also blocked off the rear of the firebox, again, either with cardboard or Dow-board. I left it on for a couple of days.

[Jolly Acres Farm]

I was in the same boat as you. I fire bricked my arch on New Years day. I heated my sugar shack to about 45°F. And I had no problems with it curing. As a side note I left the stir stick and small amount of the cement outside after the arch was completed. It was down in the teens that night. The next morning I noticed it and took it into the heated shack and threw it into the trash can. It appeared to be solid, so curiosity took over. Checking serveral times throughout the day while in the heated shack showed that it had cured outside without any heat.

[eustis22]

do you wall with splits or fulls? I used splits and my mortar cracks halfway thru the season. I've mulled sacrificing the extra space to fulls just to avoid the sides collapsing.

[Bruce L]

I also bricked in the winter,as others have said I placed a sheet of plywood over the arch and put in a small heater for about 4 days to allow for curing.

[randomseeker]

Splits vs Fulls. I assume splits are the half thickness? I'm not familiar with that term. My last unit had half thickness. I just assumed that was the norm? This is a forced air unit and will run hot. Any advice?

[eustis22]

yes, splits are the half thickness. I suppose it depends on if you have framwork holding your bricks in, which I don't have.

[jimsudz]

If you use splits I advise using a layer of ceramic blanket. I used fills and still used 1" blanket.

[mudr]

Another thought (from someone who hasn't actually done this task yet). Try a chicken heat lamp. If someone didn't have heat in the shop and didn't want to buy torpedo heater, a chicken heat lamp would be like $20, put out decent heat without being too hot. I assume it's like concrete in that you also don't want it to cure too fast?

[Zucker Lager]

I will be bricking up a small hobby arch 2 by 3 and I called the company who made the pre mixed mortar Meco's and they advised me not to do the job unless I could keep the whole thing dry and above 40. I have a friend who has a heated garage guess I will have to trailer my arch over there to do the job. Probably cost me a bottle of his favorite too. ha ha Jay

[eustis22]

I have a layer of archboard behind the splits

MY arch is 2X3 and I keep it either neither dry nor above 40

[Zucker Lager]

Hey Eustis22:
Everything set up OK with your bricking? Because if I don't have to haul my arch to a heated place I would be happy not to. The instructions call for wetting the bricks is that something you had to do? I got my cement from Menards and I'm guessing its a water base. But if I could get one that wasn't water base guess that would work? We're heading for highs around zero this next week but I could wait for a little warmer weather too. Jay

[Woody77]

Hey y'all. All cement based mortars Cure With an exothermic chemical reaction. That means they emit heat. My point is The first day you should not need heat source For the mortar to cure If the temperature is above 20 degrees. And all curing should be mostly done in 3 days. If you are in doubtAbout it freezing Cover the top of the arch with a sheet a foam or a heavy blanket to insulate it. Plug the flue and stick a lamp in the fire box with a 60watt or larger bulb and you'll be fine.good luck and don't forget to stock up on waffel mix n bacon for that first run sample.

[n8hutch]

Hey Eustis22:
Everything set up OK with your bricking? Because if I don't have to haul my arch to a heated place I would be happy not to. The instructions call for wetting the bricks is that something you had to do? I got my cement from Menards and I'm guessing its a water base. But if I could get one that wasn't water base guess that would work? We're heading for highs around zero this next week but I could wait for a little warmer weather too. Jay
I Wet my Bricks. My Masonry Friend suggested it.

[lpakiz]

Zucker,
If you trailer it to your friends garage to brick it, how will you get it home and unloaded and placed? It's gonna be plenty heavy......

[eustis22]

I do wet my bricks...this year I alkso added a skim coat over them on all the seams. As I said, I've been having seasonal issues with the mortar drying out and the walls getting wobbly on me. Since it was above 50 I let it sit for 24 hours then built a small fire in there. If I were doing it now I;d do the lightbulb for 24 hours and again a small fire.

[Zucker Lager]

Hey Ipakiz:
I have a front end loader with a set of forks so that won't be a problem I've actually been using it for the build to take the load off my back, Then I'll just park the whole shebang in the heated garage and brick it right on the trailer. Hope to finish the metal work today on my arch then its time to brick, toady its 8 degrees here and going down fast Burrrrrr. Will post picks as soon as I finish the front door frame. Jay

[lpakiz]

OK, great, you have it figured out.
When I bricked mine, I placed full bricks flat for a few courses, then full bricks on edge for a couple more courses, and then 1/2 splits on edge nearer the top. My thought was that it would make the bricks more self-supporting, as far as them trying to topple inward. Going on 4th? year now, and all is well. A good practice is to try to cover all exposed metal with some protection, either insulation, brick, or refractory. Brick is necessary only where wood might damage the insulation, altho some do brick the area under the pans, further towards the stack.

[randomseeker]

Thanks for all the feedback people! I managed to do the mortaring during our heat spell (5 degrees C) over two days. Then, as suggested above, I put an electric heater in there with a wooden cover and the remaining insulation blanket over that. It is maintaining about 70 degrees F in spite of -10 C weather and I am giving it 4 days to cure. I used a really excellent CDL Video (link below) for instructions.

https://www.youtube.com/watch?v=sxN0xxQBslg&spfreload=10

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