Secondaries after 5 minutes, can I reduce air?

xman23 said:

Oslo guys, be careful when you close off the air all the way. If you slide it to fast it over travels and lifts up opening up a air path. You can look at it when you open the dog house to lube the slide.

Click to expand...

I know exactly what you mean by this, It happened to me twice the first time was just before heading of to bed I closed off the air all the way and immediately the stove started to overheat, I was baffled, I checked all the doors and smoke tested the doors, everything was tight so I got out a fan and pointed it at the stove, this brought the temperature down enough so I headed off to bed totally mystified and bummed out that my reliable Oslo was acting erratically. The second time it happened, again just before going off to bed, I moved the air lever back and forth and when I moved it all the way back to the left again the stove settled right down. The next morning I unbolted the dog house to try and figure out what was happening and sure enough noticed that if I pushed the air control lever too far to the left the plate that closes off the air would ride up over the raised area to the left of the air intake and allow a large amount of air to enter the firebox. Now that I know this can happen I'm careful not to push too hard on the air lever when I'm closing it down all the way, I close it off by gently tapping it until I feel a little resistance. Sometimes the air control is sticky so I move back and forth a couple times to free it up before I close it all the way.

Wow, that's crazy. I've never seen that happen. I guess I'll have to take off the "dog house" (lord knows why it's called that) sometime when not using the stove and see what you are talking about. I do notice that sometimes when I go to open up the draft to full open (right) after letting the stove cool down that it is sticky, and I have to kind of wiggle it to get it to open. I wonder if that is a separate issue?

aaron1 said:

Wow, that's crazy. I've never seen that happen. I guess I'll have to take off the "dog house" (lord knows why it's called that) sometime when not using the stove and see what you are talking about. I do notice that sometimes when I go to open up the draft to full open (right) after letting the stove cool down that it is sticky, and I have to kind of wiggle it to get it to open. I wonder if that is a separate issue?

Click to expand...

The stickiness is a separate issue, although if you pushed too hard to close the draft all the way because of the stickiness then you might cause the issue I'm talking about. The underside of the plate that closes off the draft has a beveled edge so if you push hard enough it can slide up and out a bit leaving a space underneath it allowing a lot of air in. Take it apart and check it out sometime.

Interesting . . . don't think I've ever experienced the lift up. I am curious though . . . when you move the air control back does the slide go back into its normal position or do you have to take it apart to get it aligned correctly?

firefighterjake said:

Interesting . . . don't think I've ever experienced the lift up. I am curious though . . . when you move the air control back does the slide go back into its normal position or do you have to take it apart to get it aligned correctly?

Click to expand...

It just slides back to the normal position, it stays in the track and aligned but the sliding plate is just lifted a bit, up and over the area it normally stops against. I'm not sure about xman's stove but mine is 12 yrs old so maybe things are a bit sloppy in there now.

xman23 said:

LOL, Thought we all knew Oslo slang. So your air thingy is sticky, it happens to all of us. Open the front door. See the dog house That thing with the three air holes in front. Remove the two bolts, look in there and you will see the slide that moves from the lever. Lube whole thing up "Dry Lube" get at HD. I find that lasts the longest.. Graphite works to. Lube the bolts and hand tighten. Never use the front door as somehow that makes the thing sticky, more often.

Also look for a mechanical bind with the lever.

When you get done it will so smooth.

Click to expand...

thank you kind sir for ....... I"ll just stop right there Thanks. I'll give that a look the next time the stove is cold!

Although they look nice, I dont pay much mind to the flames, but rather the stove temp when I start shutting her down. It really shouldnt take an Oslo 30 min to reach 400. We usually get ours up to that in under 15 on a cold start. Leave the stove either fully open or 3/4 open until you reach desired temp. I always go above 400. About 500 or 550 works perfect for our stove, then we will begin to shut her down and engage the secondaries. When its cold, obviously the more kindling and small splits you use, the quicker the temp will get up.

Shutting her down at 200 is not the way the stove was made to operate. You're really not going to be getting much heat off the stove and into the house. The first thing I want to do in the morning or after work is rake those embers forward, stack the stove full with the air open, and get that sucker up in the 500s to put heat out. Then start shutting her down in 5 or 10 min intervals. If I did it any other way, Id have a cold house and a grumpy wife.

logger,

I've noticed that the flame pattern and amount of secondaries varies some over a temperature range as large as 200-550 degrees on stovetop. Sometimes I can shut it down a lot with only a 450F stovetop temp and sometimes I have to get her up to 550F. I think looking at the flame pattern is pretty helpful to me. Maybe if you are using the same kind of quality wood and using the same process that is not necessary for you, but I burn all kinds of wood (at present.)

I agree that getting up to 400 shouldn't take that long if you are trying! I'm up there pretty fast too. I try not to really push on the gas all the way though, as I am concerned about too rapid of firing and causing damage.

Do you find that if you break up all of the coals/embers and push them right up to where the primary air is that you get the best fires? I usually have been spreading them out and then making a little hole/notch in front of the air intake to make sure I get good airflow into the firebox. I'm still debating the best practice. Seems like it takes off pretty well no matter what I do, unless I load it too full with wood sometimes.

I also have been debating how high I need to get the stove temp before shutting down secondaries. People say that all of the heat is going up the stack if you don't start dampering it down soon, but I find that the stove really seems to rocket up higher with the air full open. Maybe that is wasteful though. I usually just try to damper it down to 3/4 and then maybe to 1/2 and check the temp as it goes up from 400 to 500-525. Then, I might damper it more if it looks like it's really blazing or just let it get up to 550. If it's at 550 I'm usually trying to damper it down all of the way or with just enough primary to keep the secondaries firing well.

aaron1 said:

logger,

I've noticed that the flame pattern and amount of secondaries varies some over a temperature range as large as 200-550 degrees on stovetop. .

Click to expand...

I dont think its possible to get secondaries with temps as low as 200, as the temp has to be hot enough to engage them.

aaron1 said:

I try not to really push on the gas all the way though, as I am concerned about too rapid of firing and causing damage. .

Click to expand...

The Oslo is a beast, theres absolutely no need to worry about getting temps up too rapidly.

aaron1 said:

People say that all of the heat is going up the stack if you don't start dampering it down soon, but I find that the stove really seems to rocket up higher with the air full open. Maybe that is wasteful though. I usually just try to damper it down to 3/4 and then maybe to 1/2 and check the temp as it goes up from 400 to 500-525. Then, I might damper it more if it looks like it's really blazing or just let it get up to 550. If it's at 550 I'm usually trying to damper it down all of the way or with just enough primary to keep the secondaries firing well.

Click to expand...

Obviously there comes a point where you begin wasting heat with the air open, but you need the air in the begining stages of a new fire or a reload. I usually shut mine to 3/4 open after the fire has started and wait for it to get up to temp. As I mentioned, shutting a full load down around 500-550 seems to work best for us. The Oslo is my 4th wood stove and we've been running it for 5 winters now. Its a workhorse and once you figure out how to operate it best, it becomes second nature.

aaron1 said:

I set up a camera looking at my chimney so I can monitor smoke from my laptop

Click to expand...

I love this place!

logger said:

I dont think its possible to get secondaries with temps as low as 200, as the temp has to be hot enough to engage them.

Click to expand...

I thought this was true as well, but I get something that looks like secondaries very quickly in the burn sometimes. Maybe on some occasions the temp in locations in the firebox near the tubes is high enough for a form of secondary burn without the stovetop temp being very high? It's a billowing cloud of flame coming from the burn tubes. It is more yellow than purple though, so maybe it's just primary combustion occurring at the tubes? Maybe air is just being sucked in through the tubes and is "blowing" through the primary flames and looking like it is secondaries when it is not. That's probably the case the more I think about it. It can happen with the stove temp as low as 200-300 range. Don't get me wrong. It's not the raging blue/purple flames that occur once the stove is really hot. I think they do go away some if I turn the draft up sometimes, and the fire shifts more to the base of the pile in the stove.

logger said:

The Oslo is a beast, theres absolutely no need to worry about getting temps up too rapidly.

Click to expand...

I think the only thing the F 500 manual says in regard to this is

"Light the fire and close the door, slowly building the fire by adding larger and larger logs."

It does say "slowly building the fire." This may be mostly to keep it from smoking by smothering it, but it may have to do with not overheating a cold stove too. I don't know. I also remember from my old VC Vigilant manual that it said to never build a raging fire in a cold stove, as you can crack the cast iron. I'm sure people have done this and had no problems, but I'd like to err a little on the safe side and just build it a little slower. Maybe I'll get more bold as the stove ages, and I stop treating it like a baby!! Maybe it's an issue of a 1 or 2 stoves out of 100 might crack if you do it so they tend to say to build a slow fire or not build a raging fire in cast iron stoves?

logger said:

Obviously there comes a point where you begin wasting heat with the air open, but you need the air in the begining stages of a new fire or a reload. I usually shut mine to 3/4 open after the fire has started and wait for it to get up to temp. As I mentioned, shutting a full load down around 500-550 seems to work best for us. The Oslo is my 4th wood stove and we've been running it for 5 winters now. Its a workhorse and once you figure out how to operate it best, it becomes second nature.

Click to expand...

Yeah, I'm still learning. I'm sure I'll get better and better. I'm just trying not to overlook too many things and come back a few years from now wondering why I did it less optimally the whole time. Why don't you just leave it full open until you get to 500-550? I guess you start getting some secondaries with the stove below 500 with it at 3/4 and it helps to heat the stove?

brenndatomu said:

I love this place!

Click to expand...

I know; it's a real geek solution! I really feel that it's the best way I have of knowing if I'm burning right though! It's surprisingly easy to create smoke with this "EPA" stove if I damper it down too quickly!

WarmBluthner said:

It took over an hour to get to 400

Click to expand...

There ya go, your answer to NOT turning the air down at 200, you turn the stove down by temps not secondary flames being visable.
Same thing was said in the many posts in this thread.

oldspark said:

There ya go, your answer to NOT turning the air down at 200, you turn the stove down by temps not secondary flames being visable.
Same thing was said in the many posts in this thread.

Click to expand...

The problem with that is that stovetop temps can be highly variable on the four corners of the stove. However, I would think that if one corner is up to 500ish, you should be pretty safe thinking about turning it down.

aaron1 said:

The problem with that is that stovetop temps can be highly variable on the four corners of the stove. However, I would think that if one corner is up to 500ish, you should be pretty safe thinking about turning it down.

Click to expand...

Yes the advice given is to find the hottest part of the stove top and use that temp.
Plus if it was only 200 in one spot it wont be 600 on the other side of the stove.

oldspark said:

Yes the advice given is to find the hottest part of the stove top and use that temp.
Plus if it was only 200 in one spot it wont be 600 on the other side of the stove.

Click to expand...

No, it wouldn't be 200 on one spot and 600 on another on my stove at least! It might be 200 and 400 though. I've seen some big differences.

I still see value in using the flame pattern, but of course, I would never turn down the draft below 1/2 until I get a stove temp of at least 400, usually higher.

aaron1 said:

No, it wouldn't be 200 on one spot and 600 on another on my stove at least! It might be 200 and 400 though. I've seen some big differences

Click to expand...

That's unusual, for me any way.

Aaron,
Im guessing the manual says "slowly building the fire" as a mere precaution and is probably meant to address the burn-in fires and breaking in new stoves. Once you've broken the stove in you can have a raging fire as quick as you want and not worry about it. In fact, my main goal with a cold house is to get the fire as hot as I can and as quickly as possible. Its a non-issue with the Oslo.

As far as me shutting the air to 3/4 open in the begining stages, thats just because I've found it doesnt make that much of a difference and I at least feel like all my heat isnt going up the stack. As you mentioned, it also helps heat the stove a little more. Every set-up is a little different so you just have to fool around until you find that sweet spot temp when you should start closing her down. My buddy and brother have Oslos too and we all agree around 500-550seems to work best. Anything lower for me and the temp doesnt seem to climb a whole lot higher, any temp higher than 550 and Im losing too much heat up the stack and risk the chance of it climbing into the red zone.

aaron1 said:

I know; it's a real geek solution!

Click to expand...

Put up an infrared camera, you could monitor exhaust temp then! Now that's a geek solution! Hmm...maybe that's not a bad idea...

I was thinking about an IR camera, actually! Good idea!! Smoke and heat measurements all in one. Maybe I could put a thermocouple probe at varying heights throughout my chimney and record all of the information! I'm just kidding of course, mostly.

oldspark said:

That's unusual, for me any way.

Click to expand...

Depends on how long the stove has been fired up too and what size wood I am using. I also am using an IR guns, so it might not be too accurate. I should try it with my mag. therm. sometime.

aaron1 said:

Depends on how long the stove has been fired up too and what size wood I am using. I also am using an IR guns, so it might not be too accurate. I should try it with my mag. therm. sometime.

Click to expand...

Begining of the fire yes, but that's not a good practice with the stove barely coming up to temp, IR testor is more accurate then the mag unit.

oldspark said:

Begining of the fire yes, but that's not a good practice with the stove barely coming up to temp, IR testor is more accurate then the mag unit.

Click to expand...

Well, the IR gun manual says it can be a bit dicey on a shiny surface. My enameled Jotul seems to be a bit shiny, but it is reasonably close to the mag. therm. Maybe for fun one day I'll borrow my friend's 2 mag. therms and put one on 3/4 corners to see what's going on during a full burn.

I need to do some more testing with the IR gun to see how accurate it really is. I find I have to kind of slowly move it around in a little circle or other pattern until it reaches a peak temp to get the best readings (most resembling the closely located mag. therm.)

oldspark said:

Begining of the fire yes, but that's not a good practice with the stove barely coming up to temp, IR testor is more accurate then the mag unit.

Click to expand...

That's a good point. I bet things are really in flux with the stove temps, etc. while it's coming up to temp for the first time after a cold start. It's probably best to just let it run with a lot of air at least 1/2 - 3/4, depending on your draft, until it gets up to the 400-550 range with the first burn from a cold stove.

logger said:

Aaron,
Im guessing the manual says "slowly building the fire" as a mere precaution and is probably meant to address the burn-in fires and breaking in new stoves. Once you've broken the stove in you can have a raging fire as quick as you want and not worry about it. In fact, my main goal with a cold house is to get the fire as hot as I can and as quickly as possible. Its a non-issue with the Oslo.

Click to expand...

logger, I don't doubt that it may not be a problem for some stoves/users depending on the stove and the draft, the wood, etc. but the manual has two sections on these topics (5.2 - breaking in your new stove vs. 5.3 - starting and maintaining a fire.) so, i think the "slow" comment is to be followed whenever we start a fire. that's my interpretation. Once the stove has been going awhile and once it's up to a certain temp, you can probably safely let it climb as fast as you want as long as it doesn't go over 600F too far. Again, people may not have problems disregarding this advice. I used to build raging (what i thought were) fires in my old VC Vigilant just b/c I didn't really care if I broke it, as it was old and not worth much, and I got kind of daring with it I guess. I don't think I caused any problems in it. Whether you crack or warp a cast iron stove probably depends on the quality of the iron used that day and the quality of the process making the stove as much as anything. Jotuls are pretty solidly built and reliable from what I've seen, so you can probably abuse them quite a bit with little/no effect.

logger said:

As far as me shutting the air to 3/4 open in the begining stages, thats just because I've found it doesnt make that much of a difference and I at least feel like all my heat isnt going up the stack. As you mentioned, it also helps heat the stove a little more. Every set-up is a little different so you just have to fool around until you find that sweet spot temp when you should start closing her down. My buddy and brother have Oslos too and we all agree around 500-550seems to work best. Anything lower for me and the temp doesnt seem to climb a whole lot higher, any temp higher than 550 and Im losing too much heat up the stack and risk the chance of it climbing into the red zone.

Click to expand...

I think you're right that it depends on the stove setup to some extent. I also feel that I'm a little at the "I at least feel like..." stage of burning, and I'd like to have a little more confidence that way. I don't expect that overnight at all. I'm just throwing around some ideas. That's why I'm at least trying to see if I can get some predictive power from monitoring all of the following during operation: stove temp, flame pattern and draft setting. I'll just keep experimenting and see what gives the least smoke and seems to give the best heating power. It's a lot of fun trying out things, safely of course.