Advice on burning Oak?

[FionaD]

I want to ask if people have discovered that different techniques are needed to burn loads that solely consist of particularly hard woods, such as oak?

I thought I was having a steep curve learning how to reuse my stove since it got fixed recently and was now behaving very differently ( presumably as it should behave!). It seemed to me that learning curve had been complicated by the fact I was exploring different ways of handling burn cycles. Now I have come to realise that there is a another factor in my learning curve... Which might make it look even more complex, except for the fact that I think it may turn out to be that this one thing has been causing the issue all along... The issue being that I seem recently to be rarely able to get any secondary burns from my current wood (which is well under 20% moisture and not huge splits.. But it IS all oak)...

So now I am wondering if the stove is not the issue, but rather the dense wood I am burning and am not used to. I've been burning hardwoods all along, but usually a mix of ash, birch and a little oak. I realised today (duh) that my wood I'm using right now, exactly since the changes in burn behaviour ( and coincidentally also exactly since my stove was fixed) is all oak. I've never burned only oak before. This is what I am discovering..

- I fill the stove up and the primary air is of course open.

- Normally, I would be able to turn the air down after around 15 mins and secondaries would arrive. The stove-top temp would be around 550-600 F by this point.

- Now however, with the oak, it's burning very differently. During the hot burn period, only the sides of the logs are flaming for ages. If I try to turn down after the usual amount of time the flames die right back and the logs smoulder. I have to open up the air again.

I have tried all manner of permutations with regard to when I begin to shut down the air ( remember, until today, I thought the issue was my stove) but it seems that all I can do is keep the air almost completely open or the flames die back and no secondaries.

This situation can last for almost two hours, during which time the stove top temp never exceeds 600 and is mostly closer to 550. It's as if the stove is struggling to be able to work hard enough to make an impression on this wood.

After almost two hours the wood finally starts to flame on the upper surfaces as well as the sides and there may be secondaries around then if I turn the air down by about 1/4 - no more, or the logs smoulder again... And the secondaries last only a few minutes before they die away.

So at this point in time, after almost two hours of flaming hard, so as I don't get smoke from my flue, the logs are now down to just red coals. They still have form, but won't for much longer... In effect this means my logs are burning quicker because of the high air flow (understandable) but cannot be burned more slowly or they smoulder without secondaries?!

Can anyone out there advise me if burning only oak really should be such a different experience and if oak is normally so reluctant to release it's gases? Am I missing something? I do recall hearing some say once, of a load of oak, "I can't get this stuff to burn"...

I feel like I'm sounding a bit crazy here.. But this really has been my experience the last few days.

 

[DougA]

Dry oak should not be a problem. Methinks your moisture meter is a bit awry.
What you describe would be very typical for 25% or higher. Are you measuring the wood after freshly splitting one? Measuring a split that was done a month ago will give you an error.
The other problem with oak is that is takes a lot of pressure to push the pins in far enough to get an accurate reading.

 

[branchburner]

Can anyone out there advise me if burning only oak really should be such a different experience and if oak is normally so reluctant to release it's gases? Am I missing something? I do recall hearing some say once, of a load of oak, "I can't get this stuff to burn"...
.

My advice (that I in fact don't always follow myself): never even THINK about burning oak until AT LEAST two years after it's been cut, split and stacked. I have no idea what the moisture content of my oak is after a certain amount of time, I just know it never seems to burn to its full potential (easy, hot, clean and long) until seasoned MUCH longer than any of the other species that I burn. Experience tells me that three or more years is best, at least for my stove (which is called the Oakwood).

 

[lindnova]

Sounds like your oak is wet. I burn oak all the time and it burns great when dry. 2 or 3 years to dry to 20% where it burns great. When under 20% it will light and burn easy and long.

Did you resplit and check the moisture level? There will be a huge difference between the weathered outside and a fresh inside split.

 

[FionaD]

Thanks for all your thoughts, which are all pointing in the same direction. That's reassuring.

I confess I don't have a moisture meter, but I ordered one today. I was trusting the people who delivered the logs last week. Their logs are described as kiln dried and guaranteed well under 20% upon delivery. They have always been very reliable to date.

Needless to say I will test a split log as soon as the moisture meter arrives and I'll be on the phone to them right away if neccessary.

Almost all of the splits have bark in one side, which I did think was a little unusual for kiln dried logs.... But I have heard no hissing when they go on the fire, so I hoped that meant they were ok.

 

[7acres]

Thanks for all your thoughts, which are all pointing in the same direction. That's reassuring.

I confess I don't have a moisture meter, but I ordered one today. I was trusting the people who delivered the logs last week. Their logs are described as kiln dried and guaranteed well under 20% upon delivery. They have always been very reliable to date.

Needless to say I will test a split log as soon as the moisture meter arrives and I'll be on the phone to them right away if neccessary.

Almost all of the splits have bark in one side, which I did think was a little unusual for kiln dried logs.... But I have heard no hissing when they go on the fire, so I hoped that meant they were ok.

If you find your the fresh face of a split to be under 20% on your new MM consider

I want to ask if people have discovered that different techniques are needed to burn loads that solely consist of particularly hard woods, such as oak?

I thought I was having a steep curve learning how to reuse my stove since it got fixed recently and was now behaving very differently ( presumably as it should behave!). It seemed to me that learning curve had been complicated by the fact I was exploring different ways of handling burn cycles. Now I have come to realise that there is a another factor in my learning curve... Which might make it look even more complex, except for the fact that I think it may turn out to be that this one thing has been causing the issue all along... The issue being that I seem recently to be rarely able to get any secondary burns from my current wood (which is well under 20% moisture and not huge splits.. But it IS all oak)...

So now I am wondering if the stove is not the issue, but rather the dense wood I am burning and am not used to. I've been burning hardwoods all along, but usually a mix of ash, birch and a little oak. I realised today (duh) that my wood I'm using right now, exactly since the changes in burn behaviour ( and coincidentally also exactly since my stove was fixed) is all oak. I've never burned only oak before. This is what I am discovering..

- I fill the stove up and the primary air is of course open.

- Normally, I would be able to turn the air down after around 15 mins and secondaries would arrive. The stove-top temp would be around 550-600 F by this point.

- Now however, with the oak, it's burning very differently. During the hot burn period, only the sides of the logs are flaming for ages. If I try to turn down after the usual amount of time the flames die right back and the logs smoulder. I have to open up the air again.

I have tried all manner of permutations with regard to when I begin to shut down the air ( remember, until today, I thought the issue was my stove) but it seems that all I can do is keep the air almost completely open or the flames die back and no secondaries.

This situation can last for almost two hours, during which time the stove top temp never exceeds 600 and is mostly closer to 550. It's as if the stove is struggling to be able to work hard enough to make an impression on this wood.

After almost two hours the wood finally starts to flame on the upper surfaces as well as the sides and there may be secondaries around then if I turn the air down by about 1/4 - no more, or the logs smoulder again... And the secondaries last only a few minutes before they die away.

So at this point in time, after almost two hours of flaming hard, so as I don't get smoke from my flue, the logs are now down to just red coals. They still have form, but won't for much longer... In effect this means my logs are burning quicker because of the high air flow (understandable) but cannot be burned more slowly or they smoulder without secondaries?!

Can anyone out there advise me if burning only oak really should be such a different experience and if oak is normally so reluctant to release it's gases? Am I missing something? I do recall hearing some say once, of a load of oak, "I can't get this stuff to burn"...

I feel like I'm sounding a bit crazy here.. But this really has been my experience the last few days.

I'm burning confirmed seasoned hickory (even denser than oak) this year and have been very pleased. When I add wood on top of live coals I will not start turning down the air till the logs on the very top have ignited. When I load a cold stove I put my tinder on the top of the wood (upside down fire method*) and will not start turning down the air till the logs on the very bottom have ignited real well. *Kindling on the top has the secondaries kicking in at the 5 minute mark on my stove. Very low smoke start up.

Only when the whole load is rip roaring will I start turning down the air. First I back it off to about 60%. I give it 10 - 15 minutes to stabilize nicely with a reduced air supply. The fire will still be very lively albeit not rip roaring any longer. But the whole load will still be engulfed with nice lazy dancing flame show. Then I'll pull the air lever down to about 30%. That's my 3 step approach that is working well for me.

1. Get the whole load rip roaring.
2. Back air down to 60% open and give it 15 minutes.
3. Back air down again to 30% open. I leave it here for the remainder of the burn.

I'll have some large cantaloupe size coals and plenty of smaller live coals too the next morning 12hrs later. So far no visible flame after 12 hrs. But I'll move around these live coals and spread them evenly. Then I load more wood in and start back at Step 1.

 

[FionaD]

Thanks for that. I'll bear it in mind if the wood turns out to be 20 % or under.

Tonight (which it is now, here in Scotland) I put a few small well-seasoned splits (not oak) under the oak splits when I put in the last load. They burned away ok and gave off 'normal' secondaries for quite some time and seemed o help the oak along quite a lot. I turned down about 3/4 of the way and the oak is burning fine with slow flames now. Not really very slow though....somewhere between billowy and a little faster.. Maybe like you describe above. Too dark to see if the flue is smoking, but it gives me hope that maybe I can mix some of the oak with other logs and it'll be alright...

But if they're way over 20% I'll need ask them to take them all away- no room here for me to store too many logs for a long time, sadly.. And anyway I paid for low moisture so that's what I want them to give me.

Hopefully the meter will arrive tomorrow or Saturday latest...

 

[FionaD]

PS.. I have noticed I find it hard to know when those billowy-ish flames are ok to leave alone. Sometimes I think they are, I think they're pretty much secondaries, but then I check outside and see significant smoke. I guess if they're mostly coming off the logs and not mid-air, then they're not the real thing, am I right?

 

[DougA]

It's easy to confuse smoke from your chimney with steam or a combination of both. A good flue thermometer along with a stove top thermometer will help you to know when to turn down the air. It does take quite awhile to get the hang of it. Many on this forum will tell you they have to re-learn when they get a new stove because they all will behave so differently.

 

[FionaD]

So my moisture meter arrived in the post.

I tried four different splits -

2 were 16% on the outside and 18% when I split them further
1 was 20 on the inside when I split it
1 was 26 on the outside and 27 inside.

So quite a mix there. I guess I need to check a few more tomorrow (it's dark out now) and see if I can get a mean %

I was only able to push the pins on the meter half way into the wood, will that still give an accurate reading?

I know I can lean towards obsession if I'm not careful - so I'll try not to check every single split!!

I guess it will pay though to check two or three splits in every basketful I bring in over the weekend, see how the logs burn till Monday and then decide whether or not I need to phone the guys who brought the logs.

I still can't decide whether I'm seeing smoke or steam coming out my chimney... Maybe a bit of each, as you suggested DougA. I'll try not to worry overmuch about that.

If it turns out the majority of splits seems less than 20% and only one split in every so many is over 20, do you think I'd get away with burning a mix of these oak splits with other more seasoned hardwoods?

 

[FionaD]

So I am pasting here a part of what I just posted elsewhere on the forum. This is probably not ideal forum practice, but I'm just doing it because it represents the end of my 'oak story'... I hope!

What has been working for me today is to pack the logs in less tightly. Normally I leave no air between the logs at all when I stack EW. Now I'm adding a few smaller splits on the coals and then several bigger ones on top at various angles, so the air can get in between them. I leave the air open till the stove top hits 600 then I turn half down for around 10 minutes, then just a hairs breadth above fully closed. Sometimes I can close it right off five minutes later, sometims I need to open a tiny bit again for a little while. But it's working... Infact the difference has been phenomenal. It will see me through this pile of oak with no more trouble, I hope.

Becuase the oak is so dense I'm not noticing much less of a burn time per load, despite packing the logs in more loosely than I normally do, so all's well on that front. Long secondary phase too. Nice to see secondaries again at last after this strange week.

thanks for the great advice Guys!

 

[Retreadsme]

Fiona, obviously you are not curing your own wood, so when I tell you that 100% of my oak is a minimum of 3 yrs old after splitting, that won't help you much I know. Your moisture meter is your best friend at this point in time. As others have said, 20% or less is almost mandatory for red oak to burn well in these stoves. One thing I do with a good bed of coals is to make my first layer (on the coals) run N-S and then all other layers run E-W. With my particular insert the air enters the box at the front, thus the air moves through the lower layer of splits allowing flames to start burning the 2nd layer of oak splits on their bottoms. Once the 2nd layer (first layer running E-W) is charred, I dial the air back to 1/2 and then in another 10-15 minutes, dial it back to 1/4.

Enjoy your Jotul and stay warm.

 

[Mellery]

Please don't laugh too much when you read this, okay? End of our first winter burning, we hired a (licensed haha) tree guy to come and take down 3 trees for us. They were standing dead and dangerous to our neighbors. We asked him to leave the wood in big rounds for us to chop, split and stack ourselves.

Also asked for delivery of a half-cord of whatever he had around that was the most dried and well-seasoned since we were starting to run low on wood. He brought us oak that wasn't dry and it sputtered and smoldered in our stove so badly we shoveled it out and threw it in the dirt outside. We finally figured out to only use one piece of it with other wood that was dry.

The learning curve is long but lessened much with the wise folks around here : )

 

[FionaD]

Fiona, obviously you are not curing your own wood, so when I tell you that 100% of my oak is a minimum of 3 yrs old after splitting, that won't help you much I know. Your moisture meter is your best friend at this point in time. As others have said, 20% or less is almost mandatory for red oak to burn well in these stoves. One thing I do with a good bed of coals is to make my first layer (on the coals) run N-S and then all other layers run E-W

I am collecting and cutting some of my own wood - but have only started doing so since I got the stove end of last year, so I'm still buying this winter. I won't ever be able to be wood self sufficient tho... Just not enough space to store enough of it to have a whole year's worth of seasoning and another year's worth being used. I wish I could.. I so envy most of you who have the space to do that.

Thanks for the advice... so helpful.

Mellery.... I'm not laughing - just nodding and smiling!. I would do the very same - and will do with some of these +20% splits if I have to!

Im feeling much more optimistic after a decent afternoon and evening's burn yesterday. Guess I'm learning that it's good to keep ones burning technique flexible and to adapt according to varying conditions and fuel type. I'm also learning more and more how great this forum is. Don't know how newbies learn to use their stoves if they don't come here...

 

[JBinKC]

My guess you built a bottom up fire and the problem is you left no escape route for the flames to hit the secondary tubes if the flames are only going up the sides of the oak as described. I am not exactly how many sets of burn tubes are on a F3cb but leave a gap in the middle when you place the logs to start a fire and use pieces that won't shift. The other thing you could do is try to establish a top down fire but it would definitely require much more kindling for oak.

 

[FionaD]

Hi JB. I am a top-downer. even though it is quite a task to top-down light in such a small firebox! But the side-only log flaming was happening at all loads - and there is sometimes 1-2 inches gap between splits and tubes

I think it's solved though... I think the side-only flaming may have been something to do with the ends being a much lower % MC, and the rest of the load being too tightly packed, plus the fact that almost all the splits have thick bark on them and the bark wasn't igniting readily. I seem to have solved this by laying the logs bark side down rather than up and having some air moving between the splits as I mentioned before.

....Early days in my solution, but so far the loads are actually burning like a real log fire!

 

[cableman]

Had some nice oak secondaries for over 3 hrs last night! . Only have oak and its only split for a year so far. I havnt been packing it real tight either

 

[FionaD]

...Feels like finding the secret to the universe !

 

[Sconnie Burner]

...Feels like finding the secret to the universe !

Its a fun toy to play with in my opinion. But I'm a new burner so that may fade. I doubt it though! Every reload is like a whole new mystery. Every piece of wood wants to start and burn differently than the other.

 

[FionaD]

One year in and no sign of it fading with me... it's growing stronger!

A friend described me recently as "someone for whom her wood stove is not so much an obsession as a disease"! I suspect I'm not alone in this forum in that respect

 

[Nick Mystic]

Here is what some good dry oak looks like when it's burning. I took these photos last night after my last reload of the night.





These photos were taken about 15 minutes after a reload on hot coals. The stove was running 400 F with the reading taken on one of the corners on the top as instructed in the owner's manual. When I shoot the center of the top with the IR thermometer it goes over the 600 F limit of my thermometer. Whenever a member cites stove temperatures it's critical they take readings from where the manufacturer specifies. My stove reads 50% hotter on the top center, but if I said I had the stove burning at 600 F then my stove would actually be over 900F on the top center, which is probably getting up to glowing stage.

 

[tinman1]

One year in and no sign of it fading with me... it's growing stronger!

A friend described me recently as "someone for whom her wood stove is not so much an obsession as a disease"! I suspect I'm not alone in this forum in that respect

Hee hee ,my wife just told me I'm obsessed with this wood burning thing ! I asked are you warmer now than last year ? She's like hell yea ! Obsession will stay !

 

[Mellery]

A friend described me recently as "someone for whom her wood stove is not so much an obsession as a disease"!

Every reload is like a whole new mystery. Every piece of wood wants to start and burn differently than the other.

When we first started burning, dealer told us his owner was "expert" at air pressure, movement, etc. and told us to buy a big box fan and put it on the floor at the end of the hall. Husband typically goes big or goes home anyway so he bought the biggest fan he could find. Loaded up the stove like the big smoke dragons of his childhood and kept the stove top at just below red-lining at all times lol never mind it was 50F outside

Since we have pretty mild winters here, I can only describe that initial time as living in the windstorm of hell lol I'm talking so freaking hot, I spent more time in the garage or bedroom with door shut and window open. Needless to say, that monster fan went back and we now have a tiny, computer-size fan at the end of the hall that is only used on the low speed and works well along with the insulated attic vent fan that is also directed to the back of the house. Have also removed an entire wall in the stove room so have an open concept house with heat moving naturally out of the stove room and kitchen area into the living and dining area too

I do remember a lovely neighbor down the street telling me one day when we first moved here, "oh wood stoves, it's a whole life." I had no idea what she meant at the time but I sure do now.

And I heartily agree, if it weren't for this site, I would probably still be living in the windstorm of hell or garage.

 

[FionaD]

That's so funny Nick M... Look what I'm staring at right now. Think this obsessive's got the hang of the oak now!

 

[TradEddie]

I'll have to agree with what everyone else here says about how long it takes oak to season properly, but we're mostly talking about American oak, but your Scottish oak is likely even worse. Firstly, it will have a much denser grain that any North American oak (cooler summer temperatures, less growth), so may be harder to dry, and those same cooler summer temperatures and wetter weather will make drying wood harder anyway. Much prettier oak for woodworking though.

TE