OWB Cleaning/sifting ashes suggestion

I'm new to these forums but have a suggestion that may help some of you with OWB. I looked through the archives but didn't see mention of this so if it has been covered before I apoligize.

Throwing away coals and getting the ash out from the coals is probably the biggest pet peeve I have with these stoves. I have a Central Boiler and this is what I came up with to seperate the ash from the coals. I'm using an old feed transfer auger. A buddy of mine was getting out of the hog buisness so he gave me the whole set up to try it out. Been using it 2 years now with no problems and works great.

I could never get the ratio down of raking the stuff forward and slowly cleaning all the time so now I do it every month or 2. I know you aren't supposed to let it go that long but most do it. Here it is set up

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What I do is put all of the ashes/coals out into 30 gal metal trash cans then feed it through the auger back into the stove. To run about 80 gals of ash/coals takes 12 minutes as I timed it today. Total set up, sifting and cleanup is a 1/2 hour. Ended up with over 50 gal of fly ash in a single run. I'd rather get dirty once than a little every day. Made up a stainless boot for it and shortened the auger but have nothing but time in it as it was all stuff that was laying around. The screening aspect of it is just drilled holes in the augers tube.

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I made a drill jig out of a piece of wood with evenly spaced holes then just clamped it to the tube with evenly spaced marks to keep it consistant. The inlet hole is small enough that it won't allow a bigger chunk to get in and stall the auger. With a short run like this the motor has plenty of power for it anyway. I'm using a 4 inch auger by the way. Some may say I'm crazy but this leaves you with nothing but fly ash. Wish I had this years ago and if anyone needs more specs let me know and I'll help if I can, Kevin

One other suggestion I'd make is to invest in a GOOD full face mask. 3M makes a really good one(part # 07193) iit runs around $140.00 bucks but it covers your eyes as well and you feel a LOT better when done. I crawl in and clean the stove out and inspect it once a year after shutting down and that alone is worth the price of the mask. I use it for all kinds of stuff now as it is really nice.

Heck of a setup.

I hate throwing away good coals.. I thought about a home made shovel out of expanded metal.. But that works backwards.. Other than scooping a shovel full out and turning around over the wheelbarrel and sifting. Then tossing the coals back in towards the back.
I had planned on building some sort of ash pan into my boiler when I was fabbing..But it seemed to be to much of a challenge at the time. (I tend to get in a hurry sometimes)

Good setup Kevin, I bet that gets dusty. I have pretty good luck using the hoe everytime I load to minimize coals in the ashes. When I do scoop them out I can usually get ashes only, maybe a few small coals. Anyway what is going on with the inside of your door, does the rest of the door have a layer of creosote and that patch has burned off? Just curious.

ericjeeper said:

I hate throwing away good coals.. I thought about a home made shovel out of expanded metal.. But that works backwards.. Other than scooping a shovel full out and turning around over the wheelbarrel and sifting. Then tossing the coals back in towards the back.
I had planned on building some sort of ash pan into my boiler when I was fabbing..But it seemed to be to much of a challenge at the time. (I tend to get in a hurry sometimes)

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You mean like this

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It works but it was just WAY too slow and gets your arms tired moving it. It's way dustier than the auger too. I leave the attached trash can half full so they don't hit the air as long. I use it now to drag the stuff out from the back.

I talked with my CB rep about ash pans and he said the reason they don't put them on is the reliablity of them. You'd lose more heat around them too. I'm guessing maybe other brands have them? I'd be interested on how they work and have held up.

blakey said:

Good setup Kevin, I bet that gets dusty. I have pretty good luck using the hoe everytime I load to minimize coals in the ashes. When I do scoop them out I can usually get ashes only, maybe a few small coals. Anyway what is going on with the inside of your door, does the rest of the door have a layer of creosote and that patch has burned off? Just curious.

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Not as bad as it looks, I just haven't cleaned since starting. I guess I should have before taking pics!

As for the door, I've found that happens when the outside air has a high moisture content(Rain, fog or melting snow) Thin as a piece of paper. Amazing how much water stays in wood or goes back in from the air, even though it been out of the weather. Some of ours was on concrete for 5 years and still sizzles when burnt. I know they say kiln dried lumber actually gains moisture once it out of the oven.

Looks like a great setup!

I have heard of people with OWBs and the ash/coal problem. My father in-law takes coals out if his every couple of days.
I have a Mahoning 200 with a forced air draft and an ash clean out door. I just open the clean out door three or four times a year and load the ashes in a wheelbarrow with a round pointed shovel.

nice idea

My OWB is a kind of hybrid Johnson. Johnsons have a lower draft door and blower that blows through a tunnel to the rear of the chamber. The tunnel is like a huge steel angle iron. Well the guy who made mine used to make Johnsons so his are virtually the same design but he added two heavy steel grates, one to each side of the angle, like this... ___/\___ sorta.
So I can shovel the ash out through the lower door and the coals stay up on the grates.
When I was shopping for OWB's I was told to stay away from grates, but now I'm really glad I didn't. I know the arguments that the grates keep the coals too far from the water so you lose on the heat transfer, but I think that is outweighed by the fact that the air from below through the grates makes a hotter fire. And one of the arguments against OWB's is that the coals laying so close to the water jacket make it impossible to get a fire hot enough to burn efficiently.
At any rate, my buddy bought a regular Johnson when I got mine and we don't see a whole lot of difference in wood usage but mine's a whole lot easier to clean.

Agree with Geez..my father in-laws OWB has the blower in the door above the fire...mine is similar to the way you describe yours, the blower blows under heavy grates...very easy to clean out.

i have not shoveled out mine yet this season. i started it 10/1/08

Not worth my time

I have shoveled about the equivalent of 15 gallons of ash since starting in September. I just let the fire get down, push the top coals way back, shovel out into a steel can and that's it. I cover the can and let it sit 4-5 days then throw them in the woods near my sand pile. I don't put them on my lawn because of the nails from pallets. Do all those coals really add up to more than a few pieces of wood? Who knows, who cares....I've got better things to do than separate fly ash from coals. But, if that's what flips your switch, have at it.

if you have a warranty problem as a crack or leak the first thing the say is "your ash line is to high"...void.....keep your ash level as low as possible....as ash's insulate the firebox too...specially the ones without grates and ash pans...you well get hotter cleaner burns..

I don't have this problem or this furnace, but I have an idea.


What if you made a little table like thing. The table top would be made out of expanded metal. Just put some short legs on it.

Clear a spot inside the funace an put the table there. Take a shovel full of ash/coals and put it on top of the table. The ash should fall through but the coals remain on th e top of the table.

Alternate between shoveling up the ashes underneath the table and removing and putting more ashes/coals on top.

As the top fills up with coals, push them off into a corner and continue.


Just an idea. Hope it helps.