Coulda picked a better time to do Keystone gaskets.. :-0

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Woody Stover

Minister of Fire
Hearth Supporter
Dec 25, 2010
13,226
Southern IN
It was warm a few days ago so I decided to let the stove go dead and change the cat gasket and bypass gasket. The steel cat was getting sluggish but I don't think that was because of the gasket. But since I've never replace either gasket in 8.5 years, I was way overdue.
My stove is rear-vented into the masonry fireplace, so I took the top-vent cover plate off for access. I immediately realized that I needed to pull the stove out to get a good angle at the cat gasket ( bypass gasket is straight down in the top flue opening but cat gasket is forward of that.)
Since I was into this thing up to my elbows, I decided to wait until my new ceramic cat got here, and not get in a hurry to re-install the stove. I ordered from firecatcombustors.com, Applied Ceramics. I said "Wow, only $90, great." Then I open the box today..it's only half the cat! Nowhere did they say "you need two of these." There was only one section in the pic, so my fault for not deducing that a full cat was coming. Still, in many instances today, they state the obvious so that even a cretin like me can understand...like "Do Not Eat" on a desiccant pack. ;lol I mean, who the heck is gonna just replace half the cat?? Sheesh.
I also got half a cat for my SIL's Fireview for $99. So it's gonna cost me $20 more for each complete cat, than I could have gotten the steelies for, from Woodstock. OK, whatever, I wanted to try the ceramics again.
I had the original ceramic that came with the Keystone, but I'm pretty sure it was getting weak...so I didn't feel too bad when I broke it, trying to gingerly coax it out of the cast iron cat housing. DOH!! <>
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I applied anti-seize to all the bolts as they suggest, even though most came loose easily.
I ended up with the stove down for three days so I had to heat with a quartz heater, with an occasional boost from the oven. Outdoor temps the last couple days and nights were fairly steady, 30-35, with some wind.
[Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0
Bypass gasket, and cat gasket behind it.
[Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0
Liner looked pretty clean, down low anyway.
[Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0
I put a longer 9" cat probe in, so that it would extend over the exhaust face of the cat. But it doesn't transfer the heat all the way back to the spring and it ends up being a flue-exit temp meter. I seem to remember that the digital probes like an Auber have an insulation sleeve and I was thinking that if I installed that to shield the shaft of the probe, maybe it would give an actual cat temp. I know a glowing cat is hotter that 800 degrees.. ;hm
I have 1000 marked with a bent paper clip since the meter face is on the back of the stove, even with the fireplace opening, and I can't see it without a mirror.
[Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0
Cat and bypass door back in, and the magnet and washer I stuck in there to hold the probe in position. I don't know how long that will stay in place (I think magnets get weak when heated,) but the probe isn't giving me a true cat temp anyway. When I get that insulation sleeve for the probe shaft, I'll drill a small hole in the cat heat shield to suspend the probe in position.
You can see the heavy-duty cast iron construction of the components in the stove in these pics, and in the service instructions from woodstove.com. At least a couple steps above what you find in a welded plate-steel stove. This stove can be torn down and totally every part replaced, so it could last forever. Like my old Pappy used to say, "It's had a lot of new handles, and a lot of new heads, but it's still the same old ax." ;lol
Adjust the bypass door tension a little on the loose side because when the stove is hot, it tightens up a bit.
[Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0
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Fired 'er back up a couple hours ago, and it's back up to my target in here, 70 degrees. :)
[Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0
 
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I use to buy that gasket replacement kit from Woodstock every 3 years. I also replaced the glass gasket at about 5 years. Did you replace the ash pan gasket as well?

Hows that cat probe working? I really liked my Auber thermocouple, it was fast and accurate.
 
I didn't do the ash pan door or load door gaskets yet, but I will the next time it gets warm out. I replaced the glass gasket when I took the windows out to get more access for patching the right front vertical seam air leak I had. That's been quite a few years, though.
The cat probe doesn't seem to read any different than the stock 8" did. Can you confirm the the Auber probe has an insulating sleeve on it? Maybe I can get some of that stuff and experiment with it. If that doesn't work, I may go with an Auber at some point, or drill a hole in the stove top and cat heat shield for a shorter probe, like you did.
The stove top peaked a bit higher last night, around 600. It's possible that the new bypass gasket is routing more smoke to the cat, or the cat gasket is sealing better, I don't know. I'll see over the next several burns whether the stove top is consistently higher, or if that was just a fluke for whatever reason..
 
There's no insulated sleeve on the Auber probe. It's been awhile but I thought it was explained to me that the thermocouple probe is two wires that run up to the tip where they connect and gives you the temp at that connection.

I don't remember the exact length I had but I pretty sure I told them what I wanted and they made it to that length.

I inserted it into the cat probe hole in the back of the stove and it rested right on top of the cat under the heat shield.
 
Stove top meter is recording 600 consistently, so I think replacing the bypass gasket is feeding more smoke to the cat. Maybe my liner will also stay a little cleaner..
I cleaned the glass today, so figured I post a pic. Yeah, I'm gonna move that wood from in front of the stove before I leave the room; Was drying a few splits that got rained on.
[Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0
 
Hmmm, need to figure out how to compensate for these grainy low-light pics..maybe jack up the megapixels on my phone camera?
 
It was warm yesterday, so I let the stove go out and replaced the tired steel cat with a ceramic. I also put back in the original cast iron cat scoop (combo flame shield and air inlet.) I didn't swap scoops for any reason in particular, just to try the cast iron again and see if I notice any differences.
First I removed the two hairpin clips and took out the stainless scoop with screen mesh. The screen works pretty well to catch fly ash before it reaches the steel cat. Then I removed the two studs that, with the clips, hold the scoop in place, then installed the brackets for the cast iron scoop.
I then wrapped the new ceramic cat sections with interam gasket and installed them in the cast iron cat housing.
With either cat, you don't have to replace interam gasket if you take the cat out to dust it.
The cast iron scoop has two layers of expanded metal to protect the cat from direct flame, and to provide turbulence in the smoke stream as it enters the cat. Beefy son of a gun, it is. >>
[Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0 [Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0 [Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0 [Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0
Nothing left to do but put the cat/housing back it, attach the heat shield which protects the top of the stove, and re-install the top flue exit cover plate (I have the stove rear-vented into the fireplace.)
Oh, and light 'er up. ==c
[Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0 [Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0 [Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0
This morning, I have the air cut all the way and the cat is still glowing. If I let the ash build up on the grate, it'll more fully block the small amount of air that can be admitted up through the grate if you stir it down to where the grate has some open slots. Then cutting the air all the way should kill the cat burn I didn't really think about it, or I would have just loaded on the coals without stirring any ash down.
No biggie..the cat's not glowing very bright at all at this point. I like a medium-low glow on the cat, where I can still see the cells. I figure it's easier on the cat. If it's cold, and you need more heat, cat's gonna glow a bit more than that, whether you have flame in the box or not.
 
Ive tried every variation of different cat and scoop and found I prefered the ceramic cat with stainless scoop. The larger celled ceramic cat burns hotter and seems to let the stove breath better. The stainless scoop catches more fly ash and prevents cat clogging better than the cast scoop.
 
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Ive tried every variation of different cat and scoop and found I prefered the ceramic cat with stainless scoop. The larger celled ceramic cat burns hotter and seems to let the stove breath better. The stainless scoop catches more fly ash and prevents cat clogging better than the cast scoop.
I noticed right away that the ceramic didn't slow down the air as much.
I think I'm having to cut the air way down, to keep the cat cooler, might be due in part to the fact that the cat is "hyper-active" when new, and it will settle in somewhat. I'm not sure how much it will settle in, or how long that might take..?
I was also thinking that the cast iron scoop wouldn't be as prone to flaming inside the scoop. That's mainly in the front, right behind the screen, and not under the cat, and it's intermittent so I don't think it's that big a deal. Still, I'd rather not see it happen. Now, last night and this morning, I did see it happen a little bit with the cast iron scoop. That might be due to the new cat running hotter than it will when it settles in, and right now it's more easily igniting flame close to the cat.
 
the cat is "hyper-active" when new, and it will settle in somewhat. I'm not sure how much it will settle in, or how long that might take..?

After 1200 hours on my current ceramic cat from Applied, I have noticed zero drop in hyperactivity. It really likes to hang near the top of the meter!
 
I didn't do the ash pan door or load door gaskets yet, but I will the next time it gets warm out. I replaced the glass gasket when I took the windows out to get more access for patching the right front vertical seam air leak I had.

How did you know there was a leak in the right front vertical seam and how hard is it to take out the glass? I have the Palladian sister stove.
 
How did you know there was a leak in the right front vertical seam and how hard is it to take out the glass? I have the Palladian sister stove.
When conditions in the firebox are right, the air coming in at a leak will create flame there. If you look at the seams when the stove is cold, you can see a thin, white line along a leaking seam, where the creo has been burned off. I took the glass out to have better access to the seam when I patched it.
The glass is easy to remove; You just have to take the screws out of the glass retainers on the sides and the bolts on the bottom where the andirons are attached. There are small pieces of gasket under the retainers to pad them against the glass, if I recall correctly.
I'd keep track of which sides of the glass panels are facing in and out, and put them back in the same way. The glass may be coated on one side. I'm not sure if that's the case with the Woodstocks or not, but best to be safe. Or call and ask them about that.
 
When conditions in the firebox are right, the air coming in at a leak will create flame there. If you look at the seams when the stove is cold, you can see a thin, white line along a leaking seam, where the creo has been burned off. I took the glass out to have better access to the seam when I patched it.
The glass is easy to remove; You just have to take the screws out of the glass retainers on the sides and the bolts on the bottom where the andirons are attached. There are small pieces of gasket under the retainers to pad them against the glass, if I recall correctly.
I'd keep track of which sides of the glass panels are facing in and out, and put them back in the same way. The glass may be coated on one side. I'm not sure if that's the case with the Woodstocks or not, but best to be safe. Or call and ask them about that.
Thank you or the description. Yes I think you are right about the glass coating - I know my Progress has it.
 
I'm having to cut the air way down, to keep the cat cooler, might be due in part to the fact that the cat is "hyper-active" when new
It's windy, and the liner is sucking like a black hole. I grabbed a magnet to use on the 1/4" air hole in the back of the ash pan housing, that feeds air through the ash grate. I can now vary the amount of air feeding to the bottom of the fire, regardless of whether or not I've stirred down ash recently. I'll also be able to balance between air wash air and grate air, as I choose. A little more fun to be had, before the season winds down. ==c
[Hearth.com] Coulda picked a better time to do Keystone gaskets.. :-0
 
Hi Woody Stover,

Remind me again how many vertical feet your chimney has - I'm trying to understand how free breathing the stove will be in my install with my 25 feet of vertical height. Woodstock tells me I should put in a pipe damper, but I really want to avoid that if I can. Does blocking the ash pan hole slow the burn down a lot?

It sounds like using the steel cat also slows down the exhaust more than the ceramic cat. Is there a choice in what you can get with the stove?
 
Remind me again how many vertical feet your chimney has - I'm trying to understand how free breathing the stove will be in my install with my 25 feet of vertical height. Woodstock tells me I should put in a pipe damper, but I really want to avoid that if I can. Does blocking the ash pan hole slow the burn down a lot?
It sounds like using the steel cat also slows down the exhaust more than the ceramic cat. Is there a choice in what you can get with the stove?
I have 16' or a little more. No, the ash pan hole isn't that big a factor in total air pulled through the stove, but blocking it is going to change the way the stove is designed to run to an extent. I'd do as they suggest; Add a flue damper, maybe two. That's a tall chimney, and is going to pull pretty hard regardless of what stove you have in there.
Why did you want to avoid the flue damper..the look? You could orient it so that the handle is hidden behind the pipe, at least from some angles.
The stove would come with the steel cat but that won't make a whole lot of difference in the burn either, with a 25' chimney. Flue dampers are going to be the best way to get the draft within spec.
 
Hi Woody Stover,

Remind me again how many vertical feet your chimney has - I'm trying to understand how free breathing the stove will be in my install with my 25 feet of vertical height. Woodstock tells me I should put in a pipe damper, but I really want to avoid that if I can. Does blocking the ash pan hole slow the burn down a lot?

It sounds like using the steel cat also slows down the exhaust more than the ceramic cat. Is there a choice in what you can get with the stove?
I would bite the bullet and put a damper in, your cat will clog with too strong a draft, ask me how I know? It's not that big a deal to put a damper in and you wont regret it.
 
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Thanks for the feedback on the flue damper. Sounds like I do need it (I already knew I did, just needed a kick in the backside).

My reluctance has nothing to do with appearance or cost - my new house is built very, very tight (it tested at 1.6 ACH50 before I made the last sealing improvements) and I am worried that I will get exhaust pulled out from around the flue damper in some situations (clothes dryer running, kitchen exhaust fan on, bath fan on, etc.). My kitchen fan will be 290 CFM, bath exhaust fans 80 or so CFM, clothes dryer rarely used but substantial CFM. Should I be worried about this? My wife is also a snoopy sniffer and always looking for sources of smoke and "bad things". I will have an air-to-air heat exchanger installed, of course.

Also, the fireplace alcove the stove will go in front of is pretty deep. The vertical section of pipe will be hard to reach. Can I install the flue damper in the horizontal pipe leading from the stove to the vertical pipe?
 
Thanks for the feedback on the flue damper. Sounds like I do need it...I am worried that I will get exhaust pulled out from around the flue damper in some situations (clothes dryer running, kitchen exhaust fan on, bath fan on, etc.)
Also, the fireplace alcove the stove will go in front of is pretty deep. The vertical section of pipe will be hard to reach. Can I install the flue damper in the horizontal pipe leading from the stove to the vertical pipe?
If you can locate the inlet below the stove box, the outside air kit (OAK) will isolate the stove venting system from any negative pressure situations in the house. Ideally, you would take the air from the windward side of the house, but with that tight envelope I don't think that would be critical.
I haven't used the flue damper at all, really, but yes I have it mounted in the horizontal tee snout section of my rear-vented setup. I think it should work as well there as anywhere else.
I also have a surface flue meter lying on the snout. Clearly not at the recommended 12-18" above the stove top, so I can't compare my temps to what others report, but it is still useful for telling me when to cut the air back so that I don't overheat the tee or liner. The back of my stove is flush with the fireplace opening, and I can easily reach the flue damper handle.
 
If you can locate the inlet below the stove box, the outside air kit (OAK) will isolate the stove venting system from any negative pressure situations in the house. Ideally, you would take the air from the windward side of the house, but with that tight envelope I don't think that would be critical.
I have designed for the OAK and plan to use it. My inlet will be well below the stove box and is on the windward side of the house (got lucky in this regard, perhaps). Sounds like air infiltration from the chimney pipe is not something I should worry about.

You've posted pictures of your install, and I am familiar with it. I will have a visible section of vertical pipe, so I can monitor flue temperatures there.