Production Woodstock IS

This also is affected by temperature. When it is really cold outside, a stove will draw harder which brings in more air. But when it is warm, stoves will not draw as hard and to compensate, we have to let more air in.

 

Canadian border gave you good advice. Once the cat and secondaries are working the goal becomes keepin the stove hot and the chimney cool. There is nothing going up there to cause problems at that point.

 

I just read the last page and a half, good stuff from a newbie IS owner. Glad the vets stepped in to advise on some tips as we have learned them over the past 2 seasons.

Paint curing, as with any new stove, the break-in fires will continually cure the paint until it's totally cured. I think I did my break-ins in early November in the first production year and I had all my first floor windows open. I think I had a small haze lingering near the ceiling while it was firing.

Learning the curves on how well seasoned your wood is and doing reloads and getting your IS to "cruise control" will take some getting used to. As a few have said, we usually can get the main air down to just under 1/4 after the cat engages and this will bring the box to black. This is when the low burn and the cat do their magic.

As I type this I just engaged my cat and have a stovetop temp of 650 with a small dance on the secondaries that are slowly fading away. This half load will take me until 5 am
and at that time I will reload and do the same thing. The daytime load (3/4 load) will run until 4 ish, low and slow. I'm burning silver maple and black birch tonight.

 

Our IS (just started the third year of use) now has the Condar item code 3-12-1 cat probe. Had to grind down a smidgen of weld bead where the probe shaft laid so the sled actuator rod cleared the probe tip while engaging the cat. Bent the shaft downward 1/16" to be sure. I seated the shaft in a thin bead of 2000* furnace cement along the ledge the shaft lays on and sealed the hole w/cement. It is solid.
With a cat burn now, the indicator says 1400* but my point is that the cat could well be hotter than that as the heat travels along the probe shaft it spills off some heat to the stove body.
Still, it is really neat to see the cat probe scale climb way way faster than the sluggish magnetic thermo on the front. This reassures me that the cat did fire up and now can experiment with "how soon can the sled be closed and still get combustor light-off?"

 

OK, ongoing questions.

I left the air on full open from this afternoon's burn (that was down to mostly coals) while we went to the hardware store. When we came back, I did a small reload (maybe half what the box could have taken) on top of a very big pile of orange coals I raked forwards. With the air full open, it took it a while before it caught well enough to get the flue temps up to 550F so I could engage the cat. Engaging the cat knocked the flue temps down to about 400F. Once the flue temps started climbing again, I closed the air to about half way open. The flames slowed down (though they'd never been what I'd call active) and began to wash around like waves. Once the flue temp started to rise again, I closed it to about 1/4 open and the process repeated. Finally, I closed it down to the first big tick above full closed. The fire slowed right down and then had something that looked like a glass flame licking right up against the glass for a long time. After a while, the stove made and abrupt air movement noise and the firebox suddenly went black.

At this point, I was concerned I had put the fire out but then I noticed the flue temps were climbing again, so I shut the air down to about half way between closed and the first big tick. Over the next half hour, the firebox showed red glowing coals just at the front left side and the flue temps pretty much stagnated. In the last 45 minutes, the flue temps have been slowly but surely rising, gaining almost 200 degrees. My wife was baking herself after her shower on the floor in front of the stove and suddenly noticed that the top of the firebox is glowing a fairly strong orange. From reading, I know this is cat glow.

1) Is the cat glow and OK thing to have going for a long time?

2) With my flue temps at 700F and slowly climbing, how high should I let them go and what's the best tactic to arrest the climb and get it to come back down a touch?

 

New addition: there's now flames around the cat visible around the cat (looking up through the window to the top of the firebox.

 

Holy crap!

It heated up enough to get a little paint smelly again so my wife went upstairs to open a window and let it vent. About a second or so after she cracked the window, the firebox suddenly burst alive and filled completely with flame rolling all over the place like a fireball from an oil tank explosion. Now the secondaries are cranking from front to back with free hanging flame wash down the front glass. Flue temps have dropped 70F and it'll take some time for me to tell what the STTs are but the stove is pinging currently.

With the OAK installed and ducted directly outside, why did the stove react to the window opening?

Is the stove suddenly filling with a fireball (no rattling, sound, shaking or anything else like I've seen on videos of back-puffs) dangerous?

 

If you haven't noticed, I posted several times in a row up there while being astonished at my stove. Most of the show is over now. It's settled down into spending long periods of time dark than suddenly flaring up with yellow flames that geyser up out of random places on the firebox floor and flood all over the place before going out again.

Here's two pictures of the secondaries suddenly lighting up bigtime after the firebox earned it's name (after my wife opened the window).
_DSC6837.jpg by Ty Williams, on Flickr

_DSC6838.jpg by Ty Williams, on Flickr

 

Don't change a thing! This is the behavior you're looking for in a good fire.

 

Hey williaty - there is another air intake on the IS other than those fed by your OAK. (Actually two more). The air supply for "cat air" is controlled automatically by a bimetallic valve on the stove rear right wall. The other is a tiny unregulated hole ("EPA air") that you can only see when the door is open.
Everything you describe the last 3 posts sounds normal except for maybe the high flue temps. If you don't have it yet, spend $20 twice more and get 2 more magnetic thermometers. Stick one on the front just right of the cat probe screw. Stick another in the middle of the center cook burner. One strategy is to wait 5 minutes after engaging the cat then slowly reducing (over a few minutes) reducing the intake lever to below 1/4 open. I think you could engage the cat and then reduce intake sooner than you are doing. The other things you describe are normal for an IS being burned very hot.

 

This is totally normal- especially in a shoulder season burn. When it gets cold there is enough pull to keep the secondaries going longer.

 

Those "cat flames" are fed by the cat-air supply I described earlier. All part of the IS magic show. Cool, huh?

 

Probably coincidence that this happened when the window was opened but as others have said there are a couple other small air intakes that do not go through OAK. However what you experienced isn't that unusual, often happens right at the point where secondaries are wanting to fire but not quite. With no primary flames your firebox is filled with combustible gasses, that your CAT is burning. But if the firebox is hot enough for secondary combustion, then it just takes a spark or little bit of primary flame to light the gasses off and you get that big woosh and the stove turns into a big fireball.

This past weekend mine was doing this repeatedly... I was right in that sweet spot with a dark firebox and then suddenly woosh! The secondaries would burn for just a minute then go out. A few minutes later another big woosh and the cycle repeats. Did that 3 or 4 times. Very entertaining to watch.

 

I get the sense you are moving the air control a lot once you get going. I did the same thing at first. Really, all that's needed is to get the stove to cat light-off, then after about 5 min set the air control down. be sure to give the stove time to react to your adjustments before making more adjustments. It's easy once you learn the behavior of your particular set up. Happy burning!

 

Depending on the wood species, I've found that engaging the cat sooner will often result in a lower chimney temp at least to begin with. This also helps with the "whoofing" fireball that happens. (By the way, it's easy to recreate that scenario every time if you open the bottom door with the air turned down, but it also backdrafts through the grate into your house when it ignites too. Ask me how I know?!?).
If the chimney is over 300 deg magnetic temp on the stack (18" up) for a sustained period of time, engage the cat and start turning down your air control, it will engage. As was mentioned already, slow and gradual adjustments of the air control are keys to keeping your cat under control.

 

Let me know how your catalyst probe works out. I purchased (not sure which model #) one 2 yrs ago and used the factory spot in the front above the door and it worked for a short time then finally the thermometer crapped out. I did some research on Condors digital version of the catalyst probe and might take the plunge if I feel it's worth it. I'm more concerned with the cats performance right now and that may be something to help me keep a closer eye on it's performance. BDF , may be able to chime in on some of his thoughts on this.

 

If you want to go digital I would look at this one. I got off ebay, only bad thing it comes on a slow boat from China. You can set alarms and record to an SD card if you want to graph the data and keep records of it that way.

 

K Type Digital Thermometer Thermocouple 4 Channel Meter SD Card Logger Generic | eBay