That was my perception but I was corrected. Something is not adding up here:
https://www.hearth.com/talk/threads/blaze-king-maintenance.78280/#post-996575
http://www.chimneysweepnews.com/Combustors.htm
2016-17 Blaze King Performance Thread (Everything BK) Part 2
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https://www.hearth.com/talk/threads/blaze-king-maintenance.78280/#post-996575
http://www.chimneysweepnews.com/Combustors.htm
Somebody posted this a couple weeks back. About as cheap as I've seen. I think all interam gasket is pretty much the same. This is from the BK cat supplier. http://www.firecatcombustors.com/ACIG-2-p/sku_acig-2.htm
At some point the EPA did make manufacturers step up to at least a 3 year warranty. Manufacturers were throwing cats in stoves so they could pass testing for the clean air act. Most of these stoves went through cats like crazy! These gave cat stoves the bad name that still plague them to this day.. Blaze King played big role in getting this done.
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Ashful
Minister of Fire
I don't think there's a conflict in anything said there. BKVP has been consistent in saying that cats will live longer in BKs than in many other stoves, due to running more controlled cat temps in a BK, versus some other stoves. So, what might be an industry standard of 10,000 hours might be much longer in a BK.
I don't put any faith in any estimate given in years. Some may run their stove 5000 hours per year, but more stove owners might average only 200 hours per year. The only lifetime estimates with any validity must be in hours of operation, not years of ownership.
I don't think we're seeing much evidence of catalyst depletion, the assumed failure mode, when discussing hours or years of operation. I think we're seeing more evidence of cat plugging, in combustors with plenty of life left in them.
I suspect very few combustors are depleted in these short periods of less than three years full-time use (e.g. < 10,000 hours). I suspect most are deformed from overheating, flame impingement, thermal shock, or ash plugging.
That was info presented by BKVP in 2009, so I don't know if it still holds. Interesting nonetheless. This chart, from the link above, is hard to read but seems to indicate that the cat needs more temp to light off as it gets older, but when it lights off, still works well:
![[Hearth.com] 2016-17 Blaze King Performance Thread (Everything BK) Part 2](https://www.hearth.com/talk/data/attachments/195/195407-cd324c676c3319b7c72f93df944f6a14.jpg?hash=hggxFroC67 "[Hearth.com] 2016-17 Blaze King Performance Thread (Everything BK) Part 2")
"When you burn wood, a bunch of VOC's are released as well as potassium magnate. In many older cat stoves, the potassium magnate attacked the substrate material, mullite or cooderite and caused the substrate to fall apart. (by the way, cat stoves destroy 100% of all VOC's when the cat is over 500F also called active.)
Combustion by products lay over the top of the surface area over time and the precious metals cannot make contact with the smoke. That in turn starts the plugging that can plague cat stoves when used improperly. (Wet wood, trash burning etc.)
Under a magnifying glass you would see the surface area of the combustor looks like the surface of the moon, tons of craters. This vastly increases total surface area and allows for more complete burning of the smoke.
When you do the major cleaning, which involves the distilled water and vinegar, the acids remove the deposited materials and once again expose the precious metals to the smoke. In essence, you can definitely rejuvenate a combustor by this process. Not likely to 100% new, but quite a bit and get some extended life from the combustor. Many owners tell us they have two combustors. One in use and the other cleaned, wrapped with new gasket and stored in a zip lock bag and ready to go. Every 6-8 years, they swap them out, clean the dirty one, regasket and store away for a another few years.
I have a King in my home and I must tell you I have never removed the combustor, not in 10 years. It burns like the day it was new and I have gone so far as to thermocouple the unit in my home to check temps and other specs. Dry wood, hot fires one and week and no chemicals are the most important conditions to assure a long life. (Keep the door gasket tension snug at all times as well.)
When a combustor is on it's last leg you will know it. The stove just will not "breath" and the wood will not burn to completion. So how do you get them to last, burn 18% or lower moisture content fuel. Never throw in wood with ice and snow and cause huge temperature swings to the ceramic, leave the door cracked as little as necessary, room air hitting the face of the combustor can damage it over time. Clean it with a soft brush and maybe vacuum at the end of each season."
This is more 2009 info from BKVP but I think it still holds true.
"Combustor Warranty
The Environmental Protection Agency requires that each stove manufacturer provide a 6-year prorated warranty on original combustors. Depending upon stove design, combustors can last or remain effective as little as 2 years (burning seasons) or up to 10 years or more. Each combustor returned to the stove manufacturer is in turn shipped back to the original supplier for testing. Without question, although small in number, the vast majority of the combustors failed due to thermal shock. Thermal shock is generally the result of rapid temperature changes (such as loading hot stove full of snow or ice laden wood) or excessive draft.
Less than .4% of all OEM combustors are replaced in the first three years of the warranty coverage. Less than 10% of all OEM combustors are replaced during the EPA mandated 6 year warranty. These figures are based upon data provided by OEM providers and resellers of combustors."
What about when you close the bypass and run the air wide open for a half hour? I think your cat temp goes pretty high, does it not?
My SIL went through a couple diesel-foils that only lasted a couple years, but I think she ran 'em hot. That's why, since I saw that, I've tried to run my cats moderately.
Highbeam would have an idea how hot the cat gets during a "weekly burn off" since he has actual numbers on his cat thermometer. I doubt the cat gets as hot as one may think since the surface temp of my stove just above the cat rarely gets much over 750F.
My thoughts are running for 30 minutes on high once a week in the shoulder seasons not going to make a significant difference in cat life and may even assist in keeping the cat clean.
What I wonder about is what actually contributes most to a clogged cat?
My thoughts are running for 30 minutes on high once a week in the shoulder seasons not going to make a significant difference in cat life and may even assist in keeping the cat clean.
What I wonder about is what actually contributes most to a clogged cat?
Tegbert
Feeling the Heat
Not a bk stove but my cat with the air closed no flames in the box shows 1000-1100 degrees per the display while stove top temps are around 450 or so. With the fan running so that number might be a little low. Running with the air open bypass closed to get the stove up to temp the display shows it can get over 900. I've had it up to 1200 though cause I got a little distracted.
Lopi Rockport
I still think a "worn out" cat might be revitalized by an acid bath (hot vinegar). Perhaps this won't give another full 10,000 hours but it might extend it a season or two. Or three.
Since I bought the fancy new condar cat meter with numbers I can now say that during the high burn of 30 minutes and/or 60 minutes the cat meter stops climbing at 1500 which is the top of the "active" range. It is entirely possible that the thermostat is starting to close the intake during the high burn between 30 and 60 minutes or that the engineering is working to cap the cat temp at a safe level.
In my experience, the cats do just stop working. They are depleted or the potassium magnate junk is masking the catalyst. You can unplug the cat as part of routine cleaning so I don't think plugging is the failure mode.
BKVP said: ↑
If you do not burn trash but rather only seasoned cordwood, in the lower 48 states it is common for the combustor in our stoves to last 10 years or more. In Alaska, many regions run their stoves up to 7 or 8 months a year. Our history shows they last about 8 years in those conditions.
Yes it did. I suppose until we have a member with any cat stove from any brand able to get 8 years we will have to wonder. Sure, Chris says 10 years but he talks to the aliens.
I've seen plenty of stoves with 8 years or even older cats. The thing is, it's not been working for many years and the person doesn't know or care. Unless it physically falls apart, people just keep on running it.
Since a BK is engineered so closely around the catalyst it wouldn't really be possible to continue using it with a bad cat. Other cat stoves that I've around still burned ok even with a bad cat. Ok meaning there isn't a huge difference in performance from when it was new.
I'll see if the photos are clear. Super close ups. So the whole cat is shown as I found it. Less than two years of burning, one soft winter and one hard winter so average weather but a long burn season of 6000 hours per year. The problems that led to my thinking that the cat died were lots of smoke, white and blue, unless at max stat setting then it would clear up until I lowered the setting.
So I first brushed the face of the steelcat with my soft paintbrush. Looks great from the door. Really looks nice but as you can see in the next pictures that beauty is only skin deep. The cells are still packed. I don't know if anybody else keeps mason bees but that's the deal. Packed cells but a clean surface.
The next step for me was to take the soft, bare, end of the shop vac hose and press it to the face of the cat. Doing this for several seconds in each circular location I could hear the junk fly through the hose. Ah ha! Success. I spent a lot of time with the vac making sure to suck out all of the cells.
Then I followed advice from here and used a low pressure setting 50 psi (keyboard air cans are 70 psi) and a tiny fuel hose to try and blast more out. At this point I got nothing else blowing out the back. I had a strong light in the stove and no debris remained in the cat for air blasting. I still went along and gave all parts of the cat a blast to be sure.
One more vacuum cycle and the final photo shows the finished product. All cells are clear and clean. There does appear to be some thin texture to the cell walls.
Still smoked for hours on restart. The cat temp falls a lot with fans on low and 50% stat setting. Higher stat settings and I get flames. I can get the cat up to 1500 still at max stat setting but the glowing fades and cat temps drop as I lower the stat to 50%. Smoke is again blue at higher settings and white at lower settings. This morning after 12 hours, the smoke was gone but so was most of the wood. I'll continue through the weekend testing but I'm afraid this cat is toast after just two years.
Tight door seal, 14% MC doug fir, bypass gasket passed dollar bill test, firm clunk on bypass, Clean chimney. I don't know what else to do.
Early next week, if the cat still looks dead, I will pull it and try the vinegar bath.
I spoke with Scott at firecat this morning. He sure likes BKs and Chris. Anyway, the price is regular price and he talked me out of ordering a new one. Said to talk to Chris and try some things first. I will do that.
So I first brushed the face of the steelcat with my soft paintbrush. Looks great from the door. Really looks nice but as you can see in the next pictures that beauty is only skin deep. The cells are still packed. I don't know if anybody else keeps mason bees but that's the deal. Packed cells but a clean surface.
The next step for me was to take the soft, bare, end of the shop vac hose and press it to the face of the cat. Doing this for several seconds in each circular location I could hear the junk fly through the hose. Ah ha! Success. I spent a lot of time with the vac making sure to suck out all of the cells.
Then I followed advice from here and used a low pressure setting 50 psi (keyboard air cans are 70 psi) and a tiny fuel hose to try and blast more out. At this point I got nothing else blowing out the back. I had a strong light in the stove and no debris remained in the cat for air blasting. I still went along and gave all parts of the cat a blast to be sure.
One more vacuum cycle and the final photo shows the finished product. All cells are clear and clean. There does appear to be some thin texture to the cell walls.
Still smoked for hours on restart. The cat temp falls a lot with fans on low and 50% stat setting. Higher stat settings and I get flames. I can get the cat up to 1500 still at max stat setting but the glowing fades and cat temps drop as I lower the stat to 50%. Smoke is again blue at higher settings and white at lower settings. This morning after 12 hours, the smoke was gone but so was most of the wood. I'll continue through the weekend testing but I'm afraid this cat is toast after just two years.
Tight door seal, 14% MC doug fir, bypass gasket passed dollar bill test, firm clunk on bypass, Clean chimney. I don't know what else to do.
Early next week, if the cat still looks dead, I will pull it and try the vinegar bath.
I spoke with Scott at firecat this morning. He sure likes BKs and Chris. Anyway, the price is regular price and he talked me out of ordering a new one. Said to talk to Chris and try some things first. I will do that.
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Very interesting information and unfolding saga Highbeam. I saw the fuzzies in my cat too and that is why I made my inquiry to Condar. After cleaning a great number of very similar a/c coils, I really wanted to blast my cat with water because past experience tells me it works. I would never clean an a/c coil with compressed air as it would bend the fins. The dislodged fly ash from an air stream is very corrosive as carbon is very hard so could likely "sand blast" the precious metal layer that is, probably, in the hundreds of thousandths of an inch thick range.
The condar process is a dipping simmering very low velocity process and is probably a much safer way to clean.
All of this being said, I am waiting for BKVP guidance. My cat is still good but that day comes.
The condar process is a dipping simmering very low velocity process and is probably a much safer way to clean.
All of this being said, I am waiting for BKVP guidance. My cat is still good but that day comes.
I really think you are reading way too far into this. Engineer by chance? We are talking about the amount of air you could force through a drinking straw, if you could access it this way. It can have 1500 degree air/smoke and flames being pulled through it but can't handle a tiny bit of room temperature air under very low pressure? I know the cat manufacturer will say not to because most people would just blast the hell out it their shop compressor. I'm not suggesting that by any means.
The long 1/8" air hose, bleeder holes on the blow gun, and 40-50 psi really make the compressed air quite safe. I can't think of a non-dirty way to say this but I blasted that hose into my closed mouth and could take it all!
Question: when you wrap a cat with the interam gasket stuff, how do you deal with the butt joint? Do you overlap, square cut butt, or diagonal cut butt?
Tegbert
Feeling the Heat
I butted the ends together on mine and used a piece of masking tape to hold it together.
Lopi Rockport
edyit
Minister of Fire
i just shot coffee out of my nose reading that, hilarious
I had a much different line written with bulging cheeks, tight lips, etc.
I overlap it, then cut through both pieces. This makes a perfect cut. I just use masking tape to hold it all in place.
I almost feel stupid for asking but is the blue masking tape okay here? Oh and can the butt joint be anywhere or do you go for a corner?
Tegbert
Feeling the Heat
While we are on the topic of cats failing what or when is the best time to do a reload? What temperature is ok to open the bypass and then the door? I guess it's hard for you BK guys to know exactly the temperature but do you let it fall out of the active zone or close to it?
Lopi Rockport
Lopi Rockport
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