The Refractory Thread!

Good advice. I will fill my chipped areas and run her. If 107 years did not destroy that brick I guess another few will not make much difference.

I am much agreeable with Paul, Do not sand blast it will just cut around the hard clinker. I have just recently had a sum what bad experience. I am taking all the stoves out of my house in Freetown ma.So far 6 removed.Some that had no linning were fine, a wings best and than a GBH #6 both stored in a celler for about 30 years or so. both fire pots were cracked top to bottom, and I mean opened right up. going back this afternoon to take out the GBH #8 and a herald in hopes they are fine . if they have brick in them I will probably take it out.I think if you use the stove with orig brick you are fine, but if it sits and can suck up moister the brick expands. I would in the future take a hack saw blade and try to clean the bricks seams what is anyones take on that???? Wilson

wilsons woodstoves wrote:I am much agreeable with Paul, Do not sand blast it will just cut around the hard clinker. I have just recently had a sum what bad experience. I am taking all the stoves out of my house in Freetown ma.So far 6 removed.Some that had no linning were fine, a wings best and than a GBH #6 both stored in a celler for about 30 years or so. both fire pots were cracked top to bottom, and I mean opened right up. going back this afternoon to take out the GBH #8 and a herald in hopes they are fine . if they have brick in them I will probably take it out.I think if you use the stove with orig brick you are fine, but if it sits and can suck up moister the brick expands. I would in the future take a hack saw blade and try to clean the bricks seams what is anyones take on that???? Wilson

Or maybe pack the pot with desiccant when you store them?

Wilson,

The original fireclay bricks in my G6 were extremely tight fitting. Even with cracks I could not get even cracked parts of them to move. I was concerned that in use that might put stress on the firepot. Plus, as you found with yours there was quite a bit of rust in behind the bricks. As you know rust is greatly expanded iron. It can expand so much that it breaks cast iron parts of the stove. What the Stove Hospital calls "Rust jacking", which is an excellent term for what is happening when there is rust forming between parts.

When I made the G6 brick molds you now have, I was concerned about the bricks being able to shift with the range of thermal expansion and the uneven temps in the pot as the coal burns to ash. I didn't want the bricks fitting so snug that they would be stressed if there was heat expansion that could cause cracks from the bricks fitting too tightly.

Before I made the molds I did some shrinkage tests with that Rutland #601. No discernible shrinkage as it cured and dried. But I couldn't figure out how to accurately measure for the very large range of thermal expansion. So I planned on fitting the bricks with a slight gap. One mold produced bricks with the gap, but the other mold came out a bit longer so I ground the ends of the bricks with a masonry abrasive wheel to so that when installed there was a 1/16 to 3/32 inch gap between each brick.

The gaps are barely noticeable in the picture, but they add up to a 1/2 inch of each row being able to shift laterally.

The other question you and I have kicked around is, should the bricks be glued in place ? I don't see that as necessary or even how it would help them. I think that gluing them would be one more thing the bricks would fight against as the try to move to deal with the temps varying throughout the pot.

And the coal holds the bricks in place, even when they are cracked. The only way the bricks can fall out is with no coal in the pot and someone moves the stove. In which case it's better to remove the bricks to protect them, plus make the stove lighter and safer when moving it.

Ash does get down behind the bricks, accumulates, and pushes them inward. But it doesn't do that evenly, so there is the risk that it could crack bricks.

I agree with you that at least once a season the side seams of at least one brick in each row should have the packed ash scraped out to get it free. Then lift out all the bricks and clean behind them. I made a hook scraper out of the end of a piece of dull hacksaw blade by grinding it to shape. Then I wrapped the rest with duct tape to make a handle.

Considering how there was no change in size with the Rutland 601 from mixed and wet to fully dried and cured, I'm not worried about summer dampness causing it to swell like fire clay likely did. My concern is that it will absorb moisture and hold it against the pot causing outward stress as the rust expands. Yet another reason to remove and clean behind the bricks once a year.

To prevent that, I may stack the bricks on the grates at the end of the season rather than leave them in place.

Paul

I'm curious to see how easily the bricks will come out, after a season of ash collection. The retaining screws that held my 111 pot together, on the split line of the 3 sections, were all loose when I disassembled the stove. So when I re-assembled it, I "didn't" tighten those screws. Maybe that will allow for some small amount of movement.

If looked at carefully, many of the joints where there are fasteners in cast iron stoves are designed with overlaps, not tightly butted joints. Over tightening the fasteners can cause cast parts to break.

Plus, the use of refractory seam sealer not only seals, it allows the seams to not need to be as tight so that the parts can move as they expand and contact.

The other thing is using the correct fasteners so that they don't need to be overly tight.

There's a reason they used fasteners called "stove bolts". Stove bolts used square nuts that were stamped out leaving sharp corners on the undersides. When put on the right way, those sharp corners of the nuts bite into the rough surface of the cast iron so that the nut can resist the ramp affect of the bolt threads that wants to unloosen the bolt/nut as the parts expand/contract from thermal cycling. If any other type of nut is used, even with lock washers, they will eventually loosen. The heat will draw the spring temper out of lock washers making them useless.

Paul

Good advice Paul, take bricks out and stack on grates,Just got back from celler in freetown. no more crack pot as far as I can tell, some stoves were stored with no brick in them a couple the brick was stacked in the ash pit. going to take a no. 8 and a wings and a herald out tomorrow and when I get them back here I wil take out the old brick no matter how good it looks. I have molds for the glen 6 you know LOL. I'm sure that Rust jacking was a major player, should listen to the young men at the stove hosapital

wilsons woodstoves wrote:Good advice Paul, take bricks out and stack on grates,Just got back from celler in freetown. no more crack pot as far as I can tell, some stoves were stored with no brick in them a couple the brick was stacked in the ash pit. going to take a no. 8 and a wings and a herald out tomorrow and when I get them back here I wil take out the old brick no matter how good it looks. I have molds for the glen 6 you know LOL. I'm sure that Rust jacking was a major player, should listen to the young men at the stove hosapital

New angles on the brick issue.......then where does this leave me. My firepot is not cracked, been over it with a fine tooth comb several times, BUT just what is between those old bricks and the wall of that cast iron firepot? As you mentioned earlier you found bricks that were in very tightly. Mine are too, but I haven't really tried to force them to move and if I do move them, cracked as they are I had better learn how to do a re-line of some sort, probably that hammer in stuff would be more manageable for me but removeable bricks in the off-season makes pure sense. Since I acquired the stove it has not been in a damp atmosphere but no idea of it's previous life over the past 107 years I do agree that tight bricks with possible rust behind them could be a cause for firepot cracks.

Wilson,

Got my fingers crossed that, hopefully, you don't have anymore moisture caused problems.

As you taught me. The best place for damp bricks is someplace where they can dry out,..... but not too quickly. I was lucky enough to have a brick dryer like yours.

Here's a pic of the first two out of the molds and into the dryer. Or should I say "under".

Paul

deepwoods wrote:

wilsons woodstoves wrote:Good advice Paul, take bricks out and stack on grates,Just got back from celler in freetown. no more crack pot as far as I can tell, some stoves were stored with no brick in them a couple the brick was stacked in the ash pit. going to take a no. 8 and a wings and a herald out tomorrow and when I get them back here I wil take out the old brick no matter how good it looks. I have molds for the glen 6 you know LOL. I'm sure that Rust jacking was a major player, should listen to the young men at the stove hosapital

New angles on the brick issue.......then where does this leave me. My firepot is not cracked, been over it with a fine tooth comb several times, BUT just what is between those old bricks and the wall of that cast iron firepot? As you mentioned earlier you found bricks that were in very tightly. Mine are too, but I haven't really tried to force them to move and if I do move them, cracked as they are I had better learn how to do a re-line of some sort, probably that hammer in stuff would be more manageable for me but removeable bricks in the off-season makes pure sense. Since I acquired the stove it has not been in a damp atmosphere but no idea of it's previous life over the past 107 years I do agree that tight bricks with possible rust behind them could be a cause for firepot cracks.

DW,
Tightly fitting bricks doesn't automatically mean a moisture problem. Ash can accumulate behind and between and make the bricks "tight",..... but that doesn't mean it's because of rust, or fireclay bricks swelling with moisture.

The real question is,.... what level of moisture has, and is, your stove exposed to ?

It's the moisture that can cause problems. If your stove is somewhere relatively dry, then I wouldn't be too concerned. However, If you live where it gets damp during the off season, such as you run dehumidifiers, you may want to think about loosening the firebricks and getting them away from the pot until it's time to fire up again.

So do you know what those tight bricks are caused by ? Is it by moisture, or just powder ash dust buildup between and behind the bricks ? Answer that and that will lead you to the best solution.

Paul

I used the Super Hybond Plus to line my stove today. Here's how I did it:
1. It first needs to be pressed into the right thickness by laying it on a piece of hardboard; using a board that is at least 1inch thick and about the same length and width as the HYbond Plus units (around 12 inches x 8inches). This can be done by kneeling on the board or hitting it with a rubber mallet.
2. Once it is the right thickness, use a large knife to cut it to shape. It took 4 pieces for my Glenwood 114. Make sure that the grate does not get blocked by either putting down a piece of cardboard first (I forgot!) or making sure you can move the grates as you put in the Hybond.
3. Fill in any of the gaps (I am not great at measuring) with scrap pieces that are left from cutting.
4. Use a wet sponge to smooth it out.
5. Using a putty knife, cut brick lines in the material.
6. Wait one week to see if it worked! I'll post! Here are some pictures:

Has anyone been to Sheffield Pottery in Sheffield Ma? I ask because they sell various refractory cement products.

I haven't Scott, but if you're interested in a little investigation ride, I'm game. Where is Sheffield anyway?

Thanks for the link, Scott.
Quite an extensive list of kiln related products on their website. Looks like they have a choice of refractory types for stoves.

I'm gonna call them and see if they have the red fireclay like Glenwood used for the original firebricks in my range and the #6. I tried unsuccessfully to find a source when I made the firebrick molds for the #6. Wilson didn't know of a source either. I still have to make molds and new bricks for the range.

My impression is that the fireclay has a smoother, denser surface than the castable and might be less prone to clinker scale build up ?

Paul

You’re welcome Paul. It’s funny what’s in your backyard....I used to live in Sharon Ct maybe 20 minutes south of there and even bought clay pots there but never paid attention to refractory hahahahaha. At the time I had no idea these stoves even existed .

I agree 100% WRT smooth faced bricks not being as prone to clinker slag build up. I’d like to try a one piece poured liner in the Stewart using the castable they refer to as “Mizzou”

Please let us know what they have to say/offer.