Charring Wood - Please Define

[jadm]

I have read here that some burners use how charred their wood is prior to shutting down air.

Sometimes, usually when I am starting up a fire - a cold start, wood is charred by the time temp. hits 400* mark - but other times - especially on a reload - temp. will be in the 400* before wood has charred. If I waited for it to char I would over fire my insert....

I also notice that if it takes awhile to char it seems like burn times aren't as long....like I let a lot of heat up the chimney while charring prior to shutting down the air and thus slowing burn down.

I also notice that if wood does not char it leaves nasty creosote on the glass when it does char later on in the burn. (This does burn off as fire continues and happens on those reload situations where I do shut air down prior to charring...)

So, please define charring under various circumstances as well as how to discern what char means -ie bottom of wood only - face of wood only etc....

Thanks

 

[wahoowad]

Charring means letting a fresh load burn fast with lots of flame to ensure that load is going to brun well, clean and get the stove up to temps. I char mine up to about 600, then take my air to 50%, then all the way down.

 

[LLigetfa]

I don't use a thermometer so I just go by how it looks. Basically I'm looking for the wood to be fully engulfed in flame long enough so that when I back off the air, the flames don't snuff out or start to smoke. Not all of the wood, just wood up front near the door on top of the coals. How long it takes to char depends on how far I let the stove burn down and what size the splits are.

If after a few minutes of less air, the load looks like it won't sustain the burn, I open it up and give it a few more minutes. If it takes longer than expected or blackens the glass, the wood is probably less than ideal.

 

[karri0n]

Similar to LLI, except that I use the flame characteristics only, as opposed to what the wood looks like. If the secondaries don't stay lit after slamming the air down all the way, I open 1/4 to 1/2, let it burn for a few more minutes, then close it down. usually this time the secondaries will stay. Once this burns like this sustainably for a good 15-30 mins, I can close the pipe damper if I am looking to sustain the burn for the overnight. Once again though, I make sure the secondaries maintain a burn.

I don't really use the word charred, as that tends to denote the appearance of the wood as opposed to what the flame is doing. I just want sustained secondaries. I couldn't care less if the wood was black or completely light tan looking. If the secondaries are going fine, I'm good to go.

 

[jadm]

Thanks for the replies. Sounds like what I have been doing - kinda going on several factors - temp., flames or secondaries. Mostly on how flames hold when air is shut down.

 

[firefighterjake]

I start shutting down the air control when my stack temp is decent . . . and then keep decreasing the air . . . as long as the secondary combustion is maintained for 5 minutes or longer I'll keep reducing the air until the air control is almost all the way "shut" or completely "closed" . . . typically when I start this whole process there are a lot of flames and the wood is starting to char (i.e. blacken up nicely as it is broken down) . . . however the key for me to start shutting down the air is based on the stack temp (and stove temp to some degree) and then watch the secondary action.