Painted wood in Oslo

[Toploader]

The previous owner of my Oslo said that she burned painted wood in the stove often, so I was wondering if that could have caused any damage to the stove. The thing I notice, even with the new baffles and insulation blanket, is that there doesn't seem to be secondary flames very often. I can't see how burning painted wood could damage a tube stove but maybe I'm overlooking something. Anyone have any thoughts on this?

 

[Grisu]

Not having secondaries is usually more a sign of the wood being too wet or draft problems. Any chance one of those could be the culprit?

 

[Toploader]

The draft is very good and the stove seems to operate just as it should, easy start ups, I can shut the primary air down completely after a half an hour and have coals after 8 hours or more for the next load. I'm happy with the way it performs I'm just not seeing the secondaries I know these stoves usually produce.
Having said that, some of my wood is a little too moist but I do have dry wood as well and still don't see the secondaries I think I should.

 

[Grisu]

Do you know your stovetop temps? When I started burning I also thought my stove was doing fine until I got a thermometer and realized I was running it too cold all the time.

 

[Toploader]

You might be onto something here because I have been running it on the cool side [350 to 450] since the whether here in Nova Scotia hasn't been too cold yet, the Oslo is such a good heater it is easy to overheat the stove room this time of year. I guess the stove needs to be really hot [500 to 600] to get good secondary burning?

 

[Grisu]

You might be onto something here because I have been running it on the cool side [350 to 450] since the whether here in Nova Scotia hasn't been too cold yet, the Oslo is such a good heater it is easy to overheat the stove room this time of year. I guess the stove needs to be really hot [500 to 600] to get good secondary burning?

Indeed, secondary combustion needs a high enough temp in order to ignite the combustible gases the wood releases. Try to make small, hot fires by putting less wood in, leave the air open a bit and let the stove get cold if you don't need the heat. It is not ideal but that way you don't make smoldering fires. Don't expect huge secondaries when you burn it that way. Have you checked whether you have smoke coming out of your chimney when you have the stove only at ~400 F?

 

[Nick Mystic]

Not so. Just the other day I loaded a 7" pine log and 5" pine log in my Jotul F600 with some kindling in between the logs. It was a cold start, so I had two small rounds (2" diameter) running N/S to hold the logs up off the floor of the stove so the dog house could feed air to the kindling in the middle. I fired it up and had the side door closed within a minute or two and it got burning so quickly that in another five minutes I had my primary air control shut half way down. I was shocked to see my secondaries firing off! The stove top thermometer wasn't even reading 100F and I could put my hand on the top of the stove. Another five minutes and I had the air shut off completely with the secondaries blasting away. I typically don't see any secondary action before the stove top gets up around 300F, so this anomaly really surprised me.

 

[Grisu]

Not so. Just the other day I loaded a 7" pine log and 5" pine log in my Jotul F600 with some kindling in between the logs. It was a cold start, so I had two small rounds (2" diameter) running N/S to hold the logs up off the floor of the stove so the dog house could feed air to the kindling in the middle. I fired it up and had the side door closed within a minute or two and it got burning so quickly that in another five minutes I had my primary air control shut half way down. I was shocked to see my secondaries firing off! The stove top thermometer wasn't even reading 100F and I could put my hand on the top of the stove. Another five minutes and I had the air shut off completely with the secondaries blasting away. I typically don't see any secondary action before the stove top gets up around 300F, so this anomaly really surprised me.

Was that maybe dry softwood? That can outgas pretty quickly and those resins are highly flammable. And in your case the stovetop is slow to get up. The temps in your firebox were probably already higher. In case of the OP, he apparently never had his temps higher than 400 F which indicates the firebox did not really reach hot temps at any time.

 

[Toploader]

Indeed, secondary combustion needs a high enough temp in order to ignite the combustible gases the wood releases. Try to make small, hot fires by putting less wood in, leave the air open a bit and let the stove get cold if you don't need the heat. It is not ideal but that way you don't make smoldering fires. Don't expect huge secondaries when you burn it that way. Have you checked whether you have smoke coming out of your chimney when you have the stove only at ~400 F?

I think you are right, I have seen smoke at say 350 to 425, so I should burn smaller hotter fires on those days when I don't need the full fire power of the stove. I do notice secondary flames shortly after I close the air down but after 10 or 15 minutes they subside and guess this is because the temp is dropping in the fire box.

 

[Toploader]

I fired up the Oslo tonight and let the stove top get up to 550 before closing off the air, the secondaries were active for much longer than I've been seeing at cooler stove top temps.
I'm wondering now when you aren't seeing secondary flames is the stove burning any more efficiently than an older stove with no secondary burn technology?

 

[firefighterjake]

I doubt burning painted wood would damage the stove . . . but it probably isn't the best thing environmentally or neighborly speaking.

 

[EatenByLimestone]

It shouldn't damage the stove. My guess is there is a wood moisture or low temp issue with the secondaries. Painted wood finds it's way into my stove on occasion.

 

[Toploader]

It's a little colder out today and running a hotter fire definitely creates more secondaries, my wood might be slightly less than optimal but just upping the temperature seems to do the trick.
Thanks for the help this forum is really great, just when you think you know it all you learn something new.
I'm still curious about when you don't see secondary flames is a tube stove burning any more efficiently than an older stove with no secondary burn technology? Is there any burning of gases happening that you might not see?