|
Post by josephcrawley on May 23, 2019 17:10:50 GMT -8
I have used firebrick for all my stove projects thus far mostly splits due to size constraints. I add reinforcement to the back and side walls to connect them to the walls of the bell in case someone gets overly aggresive with loading. There are also columns on top of the box that go to the top to place a lot of weight on the box to prevent movement.
A client recently brought up the possibilty of the firebox brick breaking and what a pain that would be to fix. My oldest stove to date is five years and has had no issues with this. Has anyone seen or heard of lifespan issues with firebrick in these stoves? He pointed out that most contraflo stoves use 2 layers of full size brick for their boxes and that a builder he spoke to of those stoves had to replace the inner layer of those bricks on a 5 year interval due to cracking.
Any thoughts, opinions, experiences?
Thanks
|
|
|
Post by Dan (Upstate NY, USA) on May 23, 2019 18:04:30 GMT -8
Yep thermal stress and banging in wood when hot and cold will crack them...
|
|
|
Post by josephcrawley on May 24, 2019 5:35:50 GMT -8
Yep thermal stress and banging in wood when hot and cold will crack them... For sure they can be physically broken. What do you think lifespan is in the environment of this firebox? The firebox from a thermal stress perspective seems rather mild. Slow heating and cooling in a fairly even environment.
|
|
|
Post by Vortex on May 24, 2019 5:47:32 GMT -8
When I was building with full sized firebricks (9" X 4.5" X 3") they were averaging 5 years in the firebox before cracking and needing replacing. Anywhere out of the flame path and they seemed to last indefinitely.
|
|
|
Post by josephcrawley on May 24, 2019 11:24:39 GMT -8
5 years what a bummer. Doing a double layer would ease replacement but would make the firebox outer dimensions enormous not to mention making the port far deeper than Peter's specs. What solutions have you guys come with up to ease replacement of bricks? aside from the obvious tear down and rebuild.
|
|
|
Post by Vortex on May 24, 2019 12:40:48 GMT -8
I found the 2" cast slabs I made for the roofs never cracked, so I started casting them for the sides as well. I make them in a way that they hold each other together and can easily be removed if they ever need replacing.
|
|
|
Post by gadget on May 24, 2019 19:38:02 GMT -8
I used some cheap splits from tractor supply last winder and I had 6 of them crack into 2 pieces right down the middle. They where $3 each. I guess you get what you pay for.
|
|
|
Post by josephcrawley on May 30, 2019 17:20:20 GMT -8
I used some cheap splits from tractor supply last winder and I had 6 of them crack into 2 pieces right down the middle. They where $3 each. I guess you get what you pay for. I have always used splits from the local masonry supply yard. They run about 1.66 for a full or split. I've had no cracking problems.
|
|
|
Post by wiscojames on May 30, 2019 17:38:49 GMT -8
I'd agree that sokits , in particular, get fragile after firing. I have broken more than a couple by "setting them down" too hard. The same is probable true of the full size bricks, but I haven't broken one yet. I've never had either one break in the fire box. But I haven't worked them as hard as lots of y'all do.
|
|
|
Post by Orange on May 30, 2019 21:10:22 GMT -8
satamax you have simple core out of few single firebricks, did they crack?
|
|
|
Post by satamax on May 31, 2019 11:29:26 GMT -8
Yep, they cracked. But nothing bad. Still holding after four seasons.
I used cut up pizza oven slabs. From italy. On the other side of the border.
The firebrick tubes tho, aren't up to the task. Five minute riser might be far better.
|
|
eng
New Member
Posts: 18
|
Post by eng on May 31, 2019 20:11:03 GMT -8
I have fire box made of slabs of castable high density refractory. This is material that I used for repairing arches in coal fired boilers. In the boilers it lasted about eight years. My burner was built about 1984 and has been used every winter since for about five months of the year. One slab has cracked but the fire box has years of use yet. A metal baffle made of 6mm mild steel has burnt away. Fire bricks made of quality material for temps 1500 deg C with similar quality mortar should last as long.
|
|