Wood stoves - Q&A FAQ

Selkirk is still a player in the industry, and their quality is good. But, all Class A (solid fuel) pipe has to meet the same standards, which these days is UL103HT. I recommend that anyone installing a stove today use Simpson pipe - just for the fact that it has by far the widest distribution, which is important if you need parts someday. (In Denver there are four Simpson wholesalers to one Selkirk outlet, and roughly 80% of the retailers sell Simpson pipe.) That's important because each brand uses a proprietary system to lock sections of pipe together. Where things are proprietary, I always go for the most common system just for ease of maintenance and repair.

A bonus is that Simpson is priced a bit better.

Also, while the old style triple wall pipe is perfectly safe, I like the double wall packed pipe. Simpson calls it DuraTech. Instead of the larger air gap and three walls, it has a 1" layer of insulation packed between an inner and outer wall. The reduced outside diameter fits between 16" on center framing while maintaining adequate clearance, making it SO much easier to work with in retrofit installations.

 

Thanks, Quigley. That's interesting, and good to know. I once saw some market share statistics that bear me out, but apparently on a regional basis my advice on most common brands could be bad.

(And I hope they're using Pellet Pro, not B vent, on those pellet stoves.)

You seem pretty aware. Are you involved in the industry somehow?

 

You sounded knowledgeable. No wonder!

BTW, Simpson Manufacturing, of Simpson Strong Tie fame, just sold the Simpson venting operation to M & G Group (out of the Netherlands) this summer. The deal should have closed by now, but it'll probably be next spring at the annual hearth industry trade show that they re-brand everything.

What interested me is that the company was rumored to be selling for about $25 million, which strikes me as dirt cheap for all the intellectual property, two manufacturing plants, the customer base and that level of distribution. M & G is a venting manufacturer with a strong European presence, so the US distribution could be a big factor - viewed in this light, $25 million to buy an existing distribution network and a huge existing customer base is a cheap way to roll a European product line out in the US market.

I'd guess some debt was assumed, and that this sale may be further fallout from the overleveraged US construction industry.

 

You need one of these with a magnetic base on the pipe

 

Glad to hear your burn went well. There's nothing like the radiant heat from a wood stove!

The connector pipe should be hot enough to stay clean. Your creosote accumulation will be higher up in the masonry chimney, at whatever point the flue gas cools enough that the creosote condenses from a vapor to a liquid. That chimney mass is enough of a heat sink that you probably couldn't prevent creosote buildup even if you burned the stove 24/7 all winter long.

Get your own brush and rods, and clean the chimney after a month of burning. If it looks good, wait two months and clean it again, and so on. I clean mine twice a season, whether it needs it or not. (And it never really needs it, but, what with wood being my primary heating fuel, it's good to check things out mid season for peace of mind.)

I would always sweep at least twice a year, particularly with older equipment.

 

ghrit,
The Coal Bear is the only "Coal Only" Fisher stove that was made. It is not designed for wood burning. That's not saying you can't or should not burn wood in them, they are just not efficient wood burners. No coal stove is.

Yes, coal requires air to come up through it, pulled by the chimney draft to burn.
Wood doesn't care if the air comes from the top or bottom. As long as it gets oxygen to burn. Wood burned on a grate will burn easily and quick. It prolongs the fire buy burning on a minimum of 1 inch of ash.
A good thing to remember with wood; The object is to make the flames change direction as much as possible with the wood. Forcing heat to travel sideways ignites it much better.

The Coal Bear should have a good quality Anthracite for optimum burn. Chestnut size. Larger is OK, but the more space between the coal, the more air it gets, and the faster it will burn. You will get the same BTU per pound, just a faster burn rate. So the warmer it is outside, you try to use the "fines" in the bottom of the bin to slow the air down through the coal when you don't need the intense heat and want a slower burn.

Once the coal fire is established, coal is shoveled in (stoked) to cover the fire and as deep as the door allows. It will burn from the bottom up. The less air, naturally the fire will stay at the bottom and not ignite the entire depth of coal. As the fresh coal on top heats up, enough heat drives the gasses out of it. The upper air damper is to allow oxygen to mix with the coal gas being driven off the coal and it will ignite with blue flames across the top of the coal. You will only get flames when burning hard, so don't expect blue flames when it is throttled down to a glow in the bottom.

Normally a coal fire requires outdoor temps to stay below 40* f. over a 24 hour period. Some stoves will draft OK depending on chimney height above those temps. That is the general rule of thumb burning coal.

Once you get the hang of coal, you won't want the work of wood, unless you get it for free and need to get rid of it. No more chimney cleaning, fill it once a day, shake it morning and night and it will burn from November until you let it go out!

Don't use the ash on plants like wood ash (potash - same as lime) Coal ash is not conducive to plants. Great for antiskid.
Coaly (bearstoves@verizon.net)

Yeah, the author of the "Everything Fisher" thread, and the guy who drove from Factoryville to Stroudsburg with the tailgate down. That old Blazer had rust holes in the front that brought the wind chill waaaay down for that hour drive.

 

For what is worth, I have a coal/wood ccokstove. I primarily burn wood in it. But one year I burnt anthracite. Difference is you have to remove the wood grate and let the coal sit directly on the shakers and there are cast iron inserts for the front and back of the firebox. Pay attention to your draft. I left mine wide open one day by mistake and the thing got cherry red, My Simmons stove pipe never got any creosote build up at all burning a mix of wood and coal. I really liked burning coal and would do it always if wood wasn't free.

 

Another thing to watch with coal is to keep the ash level below the grate. Air coming up through the grate cools the iron or steel grate itself. It will warp or melt if the ash gets packed right up to it.
After all, it doesn't take much coal in a forge to melt iron with a blower pushing air up through the coal.

Off topic of Fisher, but important tips of coal burning;
If the stove is a kitchen range with "eyes", the practice was to tilt one of them off to the side of the firebox. This allows cool air to ruch in under the cook top, and up the chimney to quench the draft. This extends the burn, and keeps the heat output down when you don't need the heat for space heating on warmer nights. It's the same principal as a barometric damper that should be on ALL coal stoves to control draft.
Many people don't know to remove the eye cover over the fire when cooking as well. The pan goes over the open hole to allow the fire under the eye to contact the pan. Ideally the cast iron pan should be the type with a "smoke ring" on the bottom of the pan. This ring cast into the pan is a raised lip at the edge that seals against the cook top better than a pan without one.

 

Bear Stoves -

Welcome! It's great to see you posting here. I've never lived in coal country and have no experience burning it. Also, my perspective comes entirely from the current era - the EPA era, if you will. As far as safety and efficiency is concerned, this is the state of the art, but it's nice to have someone around who experienced the "old days" too. As ghrit observed, you really rounds out our expertise on solid fuels.

Someday, you may have to tell a rusty Blazer story or two as well...

ghrit, the 40 degree temp thing is due to the fact that coal burns far less vigorously than wood. As slowly as coal burns, temperature differential (difference in density) is needed for draft. At the temps you did your test burn, you wouldn't have been able to maintain a draft up your chimney with coal.

 

Hi all,
Yes, a coal stove runs very cool stack temperatures. Over 40* is not enough temperature differential inside and outside of chimney. I only run 100 to 150 above the barometric damper, so outdoor temp. is critical. The fire becomes sluggish and you can loose it during the day. A tall insulated chimney will draw at nearly any temperature. When burning hard, mine runs 200 to 250 max.

When you put coal on the burning wood (it don't take much wood) you close the upper air intake until the coal catches and can be seen glowing good. It is then hot enough to open the upper air a bit to allow the gasses to light up. Only enough air to create combustion of the gasses is all. Just crack it is enough to light the blue flames. More than that allows air over the fire to rush up the stack and cool the draft. It's all about pulling oxygen through the coal bed, not over the fire.

You don't want any ash under the coal fire. When shaken, you shake until you see red glowing coals start to drop. It will burn at it's best when clean. 12 hours or so later, it will need shaking again. If it's real cold, shaking it more really puts out the heat, and burns the fuel. When you shake it, to keep things clean, you open the draft under the fire to get it going good first. Don't shake it first thing in the morning when it's at it's lowest. By getting a good draft going before the shaking, the fly ash is pulled up the chimney. They are quite clean when shaken properly.

Opening the bottom door without opening the top is a safety issue. If the bottom door were to be left open with a coal fire, you're looking at a melt down. Way too much draft.

After shaking you don't empty the ash pan until it's cold. Always use a metal bucket, but you don't want to take the hot ash with coals out. Thats a lot of BTU taken outside if you don't let it cool all the way down. The loading door is left open when you empty the ash to pull the fly ash into the stove. Not enough draft at cleaning time will allow it to settle inside. Once you figure it out, you will see a nice ash coating on top of the coal. That's the mess that would have been inside. Get it going so it pulls the fine ash up the stack.

Yes, you bank the coal deeper towards the back. A level fire isn't necessary. That's called "banking a fire" at night. In the morning after shaking, you pull the burning coal towards the front to cover the grate and fill it up. Even if it burns out in the front, no biggie. Just leave the ash there so the dead grate area is covered until you fill it. Holes in the fire or bare grate allows cold air to be pulled up the chimney without going through the fire. That chills the draft and kills the fire you do have. So always cover the open grate holes with fresh coal to block the air openings !

I run only stainless chimney caps. Nothing special I'm aware of.

The Coal Bear required a barometric damper, not manual (for coal use as it was intended) to keep a constant draft through the fire. It is much more critical with coal than wood to keep it just right. The damper can be installed vert. or horiz. You rotate the swinging door portion and level it. I personally put mine in the vert. position.

Double wall is only for reduced clearance. A short run wouldn't make much difference in cooling the draft or heat gain in the building without it. 5 or 6 feet makes a difference in stack temperature.

If you ever want to replace that Coal Bear with a wood stove let me know ! I have a New Yorker wood / coal boiler I'd trade you for it too! Like new inside. It's for radiant or baseboard heating. No hot water coil, but there is a plate for one. (New Yorker was down 309 below Allentown on the left before Highway Marine)

Here's how I got the Blazer CHEAP; Neighbor tuned it up. Points, plugs, wires. Wouldn't start. Popped, belched up carb, wouldn't run. He claimed the timing chain or gear slipped. He pulled radiator, and the front off the engine to get to the timing chain. Found the dots lined up, that wasn't the problem, cussed until I realized he would sell it for next to nothing. Sure enough, the F's and the B's flew until he says "give me a hundred bucks and it's yours". Gave him the $100, pulled the distributer cap, and sure enough he forced the new rotor on the shaft 180* out. They had a square peg on one side and a round peg on the other to prevent you from putting the rotor on backwards. But if you force it on, then tighten the screws, you can make the plastic on the rotor match the wrong holes. I saw the plastic filings on the breaker plate and knew what he had done. Turned the rotor around on the shaft, put all the parts in the back including the radiator, got in and fired it up ! Drove it a few seconds to get it next door and put it all back together.

 

Woodstoves, burning wood....questions

Recent events have prompted me to ask a few questions of those more knowledgeable than I am, with regards to woodstoves and the problems they have.
The woodstove in question was made some 30+ years ago here in Showlow Arizona. It is made of plate steel and seems to work, great at first. Within 2 weeks the thing began to show evidence of severe problems...It has NO air venturi on it, and only has the single flue pipe. It has a problem "breathing" and was NOT made supposedly for use in a mobile home. It sets on 2 1/2 inches of flagstone, sets at east 36 inches from the wall. The flue has to go out at an angle, then turn again to go up and out from the side of the mobile home. It worked fantastic a few times, then became harder to light, then last night, it began to fill the place with smoke. After tearing it down this morning, we found that the flue was coated by at east 1/2 inch of soot/lampblack deposits. Up on the roof we found that the spark arrestor, which is made of 1/4 inch hardware cloth, had become completely blocked by soot. The wood we burn is mainly of Juniper and some Cedar...all soft woods. We can get some varieties of oak, but it is very expensive to get and to have hauled in.
Now, most people in the area NO longer have ANY type of spark arrestor on their flues, due to the heavy soot build up, yet we are required by law to have them! Now it appears we will have to tear down the flues on each stove and clean them every couple of weeks or more often....
What can or should be done to help make this easier than it is now?
Thanks!

 

Get a brush from someplace like Lehmans and run it through the entire flue to clean it out. Somebody probably burned junk mail and newspaper and clogged up the the spark arrestor. Go up on the roof and unscrew the arrestor and clean it. I burn everything and have never had a problem, but my neighbor plugs up his spark arrestor when he burns junk paper because he keeps his damper turned way down. A damper has to be adjusted to what is going on with your fire, Open it up when you start a fire and let the exhaust gases burn up the flue real good. Then as your fire turns to mostly coals you can turn it down. Just my two cents.

 

I have a burn barrel for all trash and paper.....for firestarting, we use only the bark from the juniper trees. The spark arrestor on the burn barrel has never clogged and it's a very fine mesh screen......I thought it was due to burning soft woods?

 

You need to find a way to vent the stove. With the woods you are burning the fire needs to be hot, or you will continue to have the same problems. A spark arrestor with 1/4" holes is going to be a real pain in the arse!

BWM