Fire Brick Questions

At the end of last season I dutifully cleaned my Russo and perserved as recommended. I replaced all broken fire bricks at that time. So far this season I have had only wood fires in the Russo. But noticed my new firebricks are cracked and broken...actually worse than the ones I replaced.

Did I get poor quality firebricks?
Do they need room for expansion and were they too tightly installed?
What could be the cause for these firebrick failures?
What is the best way to trim fire bricks?

Looks like I will be replacing firebricks again soon. Any advice welcomed.

Thanx...hyway61
.

Hyway,

Not sure of the cause of your bricks going south so soon. Where the bricks stored in an area where they got wet prior to installation?

In answer to trimming or cutting brick I use a masonry blade on my hand held circular power saw. I mark the brick with a straightedge and then clamp it to a sawhorse or worktable and cut them. If power tools are not an option them mark the cut with a line and score it on both sides with a chisel or knife and then place it on a firm surface and a whack or two from a large cold chisel should do the trick. There is also the option of getting a special blade for a hacksaw and using that to cut with.

If the cracks are simply straight line cracks and the bricks are still firmly in place it should present no problems for your stove. If they've crumbled and are falling apart, that's a cause for concern.

I cut some fire bricks with a wet saw a while back. Like a hot knife through butter.

As far as cracks go, I replaced my brick after my first season and they all cracked fairly quickly.

I talked to a regional sales rep for Harman and he suggested just using furnace cement to fix them.

That's what I did this year. I used a liberal amount and a bar clamp or two to hold them until they dried. So far so good. I'll shut it down at the end of the week to go on vacation so I'll really get a chance to inspect things.

I really wouldn't worry about cracks in firebrick. There are different kinds of firebrick, different insulating qualities and durabilities. a good-quality high or medium duty low insulating (dense) vitrified alumina firebrick will hold up the best. However, this is not always what the stove manufacturers recommend or use, and it's almost impossible to find good-quality firebricks of the type that I mentioned in a stove shop. Many stove manufacturers use less expensive lower quality higher insulating brick (just because a brick is higher insulating or lower duty doesn't necessarily mean that it's automatically lower quality). Regardless of quality, high duty dense firebrick will outlast low duty brick by decades. In my stoves, I have Evens-Howard http://en.wikipedia.org/wiki/Evens_%26_ ... e_Brick_Co. firebrick made in the late 1880's from a defunct coal-fired boiler that's still in excellent shape and hasn't cracked (having been taken out of service, piled up, rained on, snowed on etc. for years before being put back into service) after 120 years!

Did I get poor quality firebricks?__________Possibly, but more likely it's just the nature of low duty brick- it can't handle the thermal changes as well

Do they need room for expansion and were they too tightly installed?__________possible, but unlikely that this had any significant effect

What could be the cause for these firebrick failures?___________either the low duty split is prone to cracking, or you have especially low quality low duty brick

What is the best way to trim fire bricks?_________Diamond saw blade on a cheap (you'll ruin the bearings) skillsaw both available at lows under $50

The Russo's I have use custom cast fire bricks...
The refractory used may have been a bad batch...
Use the old ones to make a mould and cast your own...
Rutland makes a good castable refractory...

Thank you all for your replys. My Russo seems to take a standard size flat brick needing just alittle trimming to fit. I purchased the bricks at a building supply store, and I believe the bricks are used for lining fireplaces and such....for stoves don't know, but they were inexpensive??? I think I have low quality bricks...they seem denser and harder then the orignal bricks... like they have more cementing agent in them. They were very difficult to trim with a 4.5 inch angle grinder. The bricks were stored outside, but I stored them inside for several weeks next to my stove. At this point I'm wondering if I should replace these bricks to protect my stove.


...hyway61

I cut mine with a Plasplugs el cheapo wet tile saw, worked great. That saw was under $100 and owes me nothing. I plan to use it for a tile job again soon. It has a 4" diamond blade. I don't see the Plasplugs brand in Home Despot anymore, but they do have cheap tile saws that are similar and handy to have around. I also cut my 8" round thimble with it, no dust storms either! I got my firebrick at a stone center. Maybe you should replace with firebrick from another source. Good luck.

I go thru 14 new firebricks per season. At less than $2, I get what I pay for. I don't notice if they crack this early in the season but if they do, I wouldn't mess with them.
The old bricks dress up the shrubs outside. Takes on a natural look

You can buy standard size fire bricks for peanuts, and cut them with a stone disc in a grinder. some builders merchants stock them. http://www.vitcas.com

Take two bricks, put them together. Wala! You now have the first crack where the bricks meet. Cracks; Not a big deal as long as they stay in place.

oliver power wrote:Take two bricks, put them together. Wala! You now have the first crack where the bricks meet. Cracks; Not a big deal as long as they stay in place.

BRILLIANT!......kind of like when I loose something, I always find it the last place I look

this is an old thread but since someone bumped it i will try to give some info from my days of casting firebrick...

best way to trim firebrick: (if its minimal grinding it with a rotella disk on a 5 or 7 inch grinder) (if major then scoring it and tapping with a hammer is best)

does firebrick need gaps for expansion: No

what could cause firebrick failure: poor quality firebricks or firebrick that was not baked in an oven slowly before being sold (prefabbed firebrick is something i would never buy personally... its cheaper and better to make the brick using Rutland or another tested and tried name brand.

Frank Russo used Rutland refractory cement and made his own brick (these were baked in a large pizza ovens prior to being shipped or installed), you can make a mold easy enough for any firebrick and just line with some oil (motor oil or whatever you have is fine). simply mix up the batch to a consistency your mold needs (if you making half rounds for a round stove the consistency will be thicker then required for flat bricks), you can let mix slake for a bit before pouring if its to wet. once the brick is dry you can remove them and set them in your oven at a low temp of 300 or whatever for several hours (we used to let a batch bake for an 8 hour work day).