TLC2000 Explosion Blew Apart Stove Pipe, Door Latch Bent up

I should clarify that I don't leave the glass door open all the time. Just for a few minutes when I'm loading the stove. My stove has no over fire air so cracking the door open when I'm loading alleviates the puff backs that I'd get with the door closed normally and the MPD open. I do have the anti-explosion plates from the DS Rite-Burn that is supposed to correct the explosion / puff back issue but I've yet to install them.

I'll still get puff backs with the Mark III, even with the fairly large over-fire air gaps at the top and bottom of the glass. Haven't had one since I cleaned the chimney though.

SMITTY wrote:I'll still get puff backs with the Mark III, even with the fairly large over-fire air gaps at the top and bottom of the glass. Haven't had one since I cleaned the chimney though.

My chimney is wide open. 8x12 tile. Never been used until this fall. I get puff backs all the time if I leave the glass door closed. Some of them are down right scary; they've shook the house. Since leaving the door cracked while loading I don't get them as often nor as violent. I usually get blue flames immediately. Well, except when I have lazy fires I still get them, they are like farts though. Not scary at all.

Here's a pic of those anti-explosion plates.

After my shake down I'll unlatch my front door just enough to crack it opened. The door is still latched but not sealed. This allows fresh air to flush the gases up and out the chimney over the top bed of coal. I'll keep it this way until I see a flame or red coals starting to shine up under the fresh bed of coals. Being warm as its been outside, it took 65 minutes for a flame. Yesterday it was 70 outside and took about the same amount of time but didn't get the flame but only red coals appearing. During the colder temps, it will take 15 to 20 minutes for the flame to appear. Then I close the door. Not having a manual air damper/slider in the firebox, I have to crack the door for the air. This seems to help in my case.. Good luck and you'll enjoy the stove!

Tony -

I was just wondering yesterday how your coal burning was coming along! I had several puffbacks, although not that violent, last year when I was first learning how to burn coal. It sounds like you had "the perfect storm" conditions for a puffback. In addition to what others have said, I would try to not let the coal bed get down so far before loading more. Putting on a large load of fresh coal = lots of volatiles. Good Luck!

I'm On Fire wrote:Its on a heat sensitive clock spring so when it reaches temp it shits the air off...

Wow!!! Glad my DS doesn't do that!

This is my second season burning coal. So far I've had no puff backs this year. I have a furnace but it operates quite nearly the same as a hand fed stove. My refueling ritual goes like this -

1. Open ash pan door and shake grates. (access to the shaker is only with the ash pan door open)
2. Open the load door and beat down the coal bed, then close the load door.
3. Immediately shake the grates again. (I always tend to shake with the load door closed so the coal bed can start to rev up)
4. Dump the ash pan.
5. Open the load door - Add 3 to 4 shovels of coal (20-30 pounds). This brings it to the top of the fire bricks.
6. Then I rake it somewhat level with it mounded somewhat in the middle. Prop load door open 1/4 inch.
7. Slice and poke up thru the bottom side of the grates for better combustion air access to the coal bed.
8. Leave ash pan door open until the blues come out and my flue pipe reaches 250 degrees.
9. At 250 degrees on the flue pipe I close the ash pan door.
10. When the flue pipe temp falls below 200 degrees I'll close and latch the load door.

In step 6 you notice I have the load door propped a quarter inch open. This keeps the volatile gases from building up in the fire box. IN step 10, I've let the coal bed slow down from producing an excessive amount of volatile gases so it doesn't puff back after the load door is closed. I also leave a very small amount of air coming in over the fire at all times so gases off the top have oxygen to burn and this prevents the build up of volatile gases too. If you have a manual damper you should have it open thru this whole process. Closing the MPD should be the last on the list. I use a baro, but sometimes I'll close the MPD 3/4 closed when its really cold and can't get my draft under .05" WC with the baro.

There are other variables too. This year I'm burning red ash and this stuff has been very user friendly. The white ash I burned last year liked to flash at me occasionally lol.

In a nutshell, its important to have a fair amount of fresh air coming in over the fire after loading. After that, its important to have a much much smaller amount of air coming in over the fire. I think if you apply this to your shake and re load ritual, you will fix your puff back issue

I've read 30-40 pages of info and I have found some people say: do not leave the ash pan door open, and others say leave it open.

Also, could someone answer this with a yes or no: Should I never close the glass door unless I see blue flames after a loading?

I can't seem to get definitive answers after reading so many threads on puffbacks. I know that allowing the gasses to build u is what causes it, but I need to know what PROCEEDURE prevents it.

Lightning: you have contributed greatly with an actual proceedure. But someone else says to not open the ash door to liven the fire and to only use the air intake adjustment.

Anyway, if I can get an answer on whether to never close the glass door unless I see blue flames, then I'll feel like I know enough to preven this again.

tony17112acst wrote:But someone else says to not open the ash door to liven the fire and to only use the air intake adjustment.

I don't think using the ash door to liven the fire is really a problem, just don't leave the room while it's open. It's too easy to forget about it, and in 10 mins or less you have a raging fire.

tony17112acst wrote:Anyway, if I can get an answer on whether to never close the glass door unless I see blue flames, then I'll feel like I know enough to preven this again.

If I get in a situation where I don't see the blue flames, I will push back some of the fresh coal in one corner of the firebox, so that some of the red hot coals are exposed. I haven't had any puffbacks with this method.

tony17112acst wrote:I've read 30-40 pages of info and I have found some people say: do not leave the ash pan door open, and others say leave it open.

I agree with LD, having the ash pan door open to rev up the fire is ok. Forgetting its open would be catastrophic. I use a BBQ remote thermometer. It has an alarm that sounds when my pipe is 260 degrees. I can direct you to a thread with more on this if your interested.

tony17112acst wrote:Also, could someone answer this with a yes or no: Should I never close the glass door unless I see blue flames after a loading?

I'm assuming this is your load door? Leave it cracked open until the blue ladies come out to dance.

tony17112acst wrote:I can't seem to get definitive answers after reading so many threads on puffbacks. I know that allowing the gasses to build u is what causes it, but I need to know what PROCEEDURE prevents it.

Letting the load door cracked open after loading should prevent it.

tony17112acst wrote:Lightning: you have contributed greatly with an actual proceedure. But someone else says to not open the ash door to liven the fire and to only use the air intake adjustment.

Glad to help Everyone has their own technique.. Just don't forget its open

tony17112acst wrote:Anyway, if I can get an answer on whether to never close the glass door unless I see blue flames, then I'll feel like I know enough to preven this again.

Yes, you need the blue flames before closing the load door completely. The blue flames prove that the combustible gases are burning instead of building up inside the fire box.

There is one simple action that would have prevented this: leaving the MPD wide open after loading. You have two choices, either burn the gases requiring air on top of the coal bed and enough heat to make blue flames or vent them up the chimney. The rest is over analysis.

To be real simple you will never get a puff back if you load in a few layers giving each 10 minutes or so to catch.

To be less simple never open the ash door except to remove ash pan.

To recharge stove first put on a modest amount of coal and open air shutter a modest amount. In 10 minutes when that coal is producing flames you can shake down the stove and add a larger amount of coal. Keep the air at a medium point or less. Manual pipe damper should be open. It is very important to never ever run air through the coal bed full blast after shaking down. Maybe to save a dying fire but only then. Running air full blast is what causes puff backs. The velocity of the air prevents the gas from burning while generating gas at maximum until the buildup reaches a critical point and boom. The blue flames you see when you open the door, or puff is not because you gave it air but because you gave it less air through the coal bed by bypassing it with the door open.. The blue flames were being blown out, away from their ignition point. Opening the door causes the gas coming through the coal bed to slow down and ignite and if there is a large accumulation above the bed it also ignites with a whoosh or boom.

Spend some time and observe your particular stove and how it behaves with different amounts of coal load and air adjustment. In mild weather there is nothing wrong with a shallower bed.

To kill your fire just shovel ash on it.

OMG, NOW we're getting somewhere!!

Quotes that help me tremendously from the very recent previous posts:

lightning:

Yes, you need the blue flames before closing the load door completely. The blue flames prove that the combustible gases are burning instead of building up inside the fire box.

LD Posse:

If I get in a situation where I don't see the blue flames, I will push back some of the fresh coal in one corner of the firebox, so that some of the red hot coals are exposed. I haven't had any puffbacks with this method.

franco:

you will never get a puff back if you load in a few layers giving each 10 minutes or so to catch.

franco:

It is very important to never ever run air through the coal bed full blast after shaking down.

franco:

Running air full blast is what causes puff backs.

franco:

The blue flames you see when you open the door, or puff is not because you gave it air but because you gave it less air through the coal bed by bypassing it with the door open.

I just got up out of bed to post this because I was revisiting what happened. In my initial post, I stated that I didn't see blue flames. But I DO REMEMBER now that when I didn't see the blue flames after closing the load/glass door, I opened it up and there they were! I closed it again and they disappeared. I then opened it a 3rd time and they came back. So every time I closed the door, they disappeared and every time I opened it, they came back. Seeing them, I closed the door and went up to the garage.

franco's information explains what is happening there. But how do I know when it's safe to close the door after seeing the blue flames? I saw blue flames and then closed the door and got the explosion. would it be a rule of thumb that it's safe only when you see blue flames while the load door is open and you CONTINUE to see them steadily after closing it? ...because my blue flames went out when closing the door.

That is probably the most important thing I need to know at this point, so any input on it is welcomed!

I have learned everything else I think I need to know otherwise:
* Leave a red glowing corner when loading;
* Never close the load door without seeing blue flames;
* If you have a low fire with very little coal, add smaller amounts, not one huge load;
* Puffbacks are more likely to occur on a warm day;
* Running fresh air at full blast will cause a puffback since the draft is too strong, not allowing the gasses to ignite.

...so I feel like if I get an answer to the above question, I'll feel like this is wrapped up. Thanks again everyone!!

-Tony

P.S. franco, putting ashes on the fire is a great idea for me since I don't have sand or dirt readily available. I suppose I could grab the spade in the garage and start digging in an emergency, but since I have 2 ash pans, I always have one full of cold ashes from a few days before (allowing them to cool down before discarding them).

The same with me Rob.

Don't beat yourself up too bad about this. You seem to have a fairly big "puff" but for hand loaded stoves, everyone deals with something like this. Yours was a bit bigger than normal, but it does happen.

For what it is worth, I put my stove pipe together using rivets instead of screws. When I had an explosion earlier this year, the stove pipe held together. Just be sure to use Stainless Rivets. Was rivets the reason it held together or not? I am not sure, but it is how I have put stove pipe together for years.

Rob R. wrote:I used to run a large Hitzer stove that was very prone to puffbacks. The one thing I did that made all the difference was to leave some burning coal exposed when I reloaded. I also added the coal in 2-3 steps if the fire was low. Once I followed those rules, I never had another puffback.

LDPosse wrote:Tony -

I was just wondering yesterday how your coal burning was coming along! I had several puffbacks, although not that violent, last year when I was first learning how to burn coal. It sounds like you had "the perfect storm" conditions for a puffback. In addition to what others have said, I would try to not let the coal bed get down so far before loading more. Putting on a large load of fresh coal = lots of volatiles. Good Luck!

I'm On Fire wrote:Its on a heat sensitive clock spring so when it reaches temp it shits the air off...

Wow!!! Glad my DS doesn't do that!

Damn smartphone auto correct, it was supposed to be "shuts".