Minor Explosion in Coal Stove

Hello Wayne, we try to keep each thread on topic, so for your question about coal quality, take a look at this thread: Coal Quality From Various Sources Bad coal would be characterized as not burning well, or completely or not burning very hot.. or leaving hard ash that the shaker grates can't grind up or get to fall through into the ashpan.

For your question about the minor explosions, re-read this thread we are on. It has a very good description about how and why the explosions happen.

I'd just ask the Amish where they get their coal. They may be forthcoming with an answer. I will say that in my area, the N. Indiana, N Ohio and S, Michigan area, if the coal poor quality, the Amish will be quite vocal about it to the retailer!! So you should be OK buying from them, but this is by no means a guarantee. If they sell the coal to each other, it should be good quality.

Hope this helps..
Greg L

Had my first explosion today-actually 2 of them. I reloaded too much in too short a time. I did leave a section uncovered but after the reload that section did not have any flame by the time I closed the door. I waited a while with the ash door open. I slowly opened the fill door several times and saw no flames so I just kept waiting. Finally I opened it again and wooooosh. I closed the door. This probably blew out the flame quickly. Then within a few seconds-woooooooosh, and puffs of smoke and some ash out of the pipe fittings and the ash door. Left a little dust around but not bad. I fortunately had already emptied the ash drawer otherwise I might have seen a huge cloud of ash. My fault. I think I loaded it too deep in the area I covered and took too long loading it so the flames went out in the open section. I have now become a member in good standing I guess. This was in my boiler so there was a pretty good quantity of new coal and gas ready for the party. I think the hopper arrangement on my Hitzer in the living room makes this situation much less likely to happen.

This is my second winter with our Alaska Kodiak and this has happened to me twice over the last two days. My normal way of loading was to just use the shovel that came with our coal hod and put an even amount over the entire bed of coals. When I had this problem I loaded by just picking up the hod and dumping it in. Then I would use the shovel to evenly cover the entire fire. We tend to get a good size air pocket under the coals and sometimes when I shake the grates the entire bed of embers will drop down 4 or 5 inches. I thought this explosion we had was just that air pocket bursting but after reading the explaination for this it appears to be the trapped gas. I notice if I use the poker and go down throught the fire to the grates in 4 or 5 loacations that makes the embers drop before I shake the grates. How often should I poke the fire like this and would poking the fire also help prevent this from happening? Thanks.

Tom Martino

You really need to leave a corner of the fire open, not covered with fresh coal. the open fire will act as a pilot light and keep buring off the coal gas. After the fire has burned for say 30 minutes, then you can add more coal to the corner or side you left open.. the rest of the fresh coal will be burning and have the 'blue dancing flames' .

Greg L.

tpmar wrote:I notice if I use the poker and go down throught the fire to the grates in 4 or 5 loacations that makes the embers drop before I shake the grates. How often should I poke the fire like this and would poking the fire also help prevent this from happening? Thanks.

I find that after the fire has been going for a week or so, I'll need to poke down into these air pockets while twisting the poker to break up any clumps. This allows me to "puncture the air pockets, break up any clumps & shake down completely & then fill with fresh coal. Leave a section uncovered & blazing all the time until the whole bed is blazing. (This will burn off volatile gases & stop puff backs)

The procedure I use is to shake down first (until I see a few embers drop....Then poke & twist & then shake a little more. (not too much shaking or you'll pack the coal bed to tight for air to easily go through it)
Takes some practice with your particular set up.

On cool to cold days this whole procedure will usually take 20 minutes or less.

Thanks Devil; That's just the sort of advice I was looking for. I'll give this technique you describe a try.

Tom Martino

Had yet to have the pleasure of the blue ladies lickin' my face till tonight!
Waiting for the mechanic to arrive to check out the misbehavin' brakes on a delivery truck...
Left alone in the shop while others went on a beer run...
They had the King O' Heat with the ash door open, 60 lbs coal in the stove heating up and about 30 lbs of coal in the hods...
Being the kind person I am I tossed the coal in the hods on to the cherry red coal in the stove...
All at once...
Then decided to see what was happening...
Nothing...
20 minutes later someone else opened the loading door to check and and I was watching closely...
The Ladies came out to smootch...

The other stoves I load always had an area of open flame, this was a bigger stove, with a bigger load of coal.
Lesson learned...
Never...
Ever...
Bury the fire under a blanket of new coal!

Lesson learned...
Never...
Ever...
Bury the fire under a blanket of new coal![/quote]

At 9:30 this AM we had a SMALL explosion in the Harman... I added about 1 to 1.5" inches of new coal at 8:30 with the lower draft knob set at 1 1/2 turns. Stack temp (magnetic) at 200*F the manometer was about .05wc. Two days ago we were given 10 bags of blaschak nut (had been burning Kimmels nut). The over fire air controls were set very close to, but not shut. All was good at this point. The fire was burning strong. Then I added a full coal hod of Blaschak to the fire. This is the most coal we have had in the stove at one time, up to the top of the fire brick + mounded way up in the middle. So far so good. I went back to the stove because it was slow to respond from all the cold fresh coal. I opened the ash door about 3/4" for four to five minutes, shut the ash door then went back to the coal forum. About 10 minutes later POOOOFFFF.
I jumped to the stove opened the overfire vents 2 turns...The blue ladies were burning well. lots of dust... Ran the shop vac to cleanup the dust. Checked all the stove pipe sections etc...
About 45 minutes later the manometer was reading LOW @ .015-.025. I removed the low side tube and blew back through to the stove pipe. The line was clear. I reset the zero on the Dwyer manometer ... Still reading LOW.
Long story short the flue CLEANOUT door had blown open.
Never cover the hot coals completely with fresh coal.
RS

PC 12-47E wrote:Never cover the hot coals completely with fresh coal.

I agree! I have never had a puff-back when I left some flame showing when reloading with fresh coal.( If I inadvertently put to much coal & hide the flame, I move some away to expose hot coal & create a flame & even open the load door a few times to give it air to encourage a flame)
I think we had a similar topic last year & evidently, some people can just dump coal in & never have a puff back........I always have to leave a flame showing to burn off volatiles. (maybe it's stove & chimney dependent?)

PC 12-47E wrote: Long story short the flue CLEANOUT door had blown open.
RS

I have had the same thing happen, since then I add my coal in two stages and have a cement block leaning against the cleanout door for extra insurance.

I've been getting them too, sounds like someone threw a rock up against the side of the house.

There is a true story of a guy that put wood in his wood stove that was cut near an old arsenal and test range. The tree had grown around a small unexploded shell. It blew up his stove!

Dann757 wrote:There is a true story of a guy that put wood in his wood stove that was cut near an old arsenal and test range. The tree had grown around a small unexploded shell. It blew up his stove!

Hmmmmm...

Sounds like an "Urban Legend" to me!

(Have a link to that story??)

I remember reading that story years ago, can't find any proof. Have to relegate it to the urban legends archives.......

I'll relate what I experienced last week. I have been asked, if I ever get "puff backs", which I was able to say, "no I haven't".

Last week I filled the stove with coal as always, but decided to leave the MPD open to see what happened. While I was sitting there watching, all of a sudden the "blue flames " appeared and came clear out of the stove via the space between the glass and the door. .. a "puff back"! Conversely, doing the same thing with the MPD nearly closed, the blue flames appear very gradually, may even go back out, but eventually the whole bed of coal will "gently" be covered with them. .. no "puff back"!

Brotherhood of the hot rocks here I guess. It's like getting burnt on the thing. Everybody gonna have to do it at least once.