Pond Boss Forums GENERAL QUESTIONS Property Projects & Construction Wood stove and draft?

Hey guys I have a very odd problem with my wood stove in my shop. Here is the story.

I had a wood stove that was home made out of two 45 gallon barrels. The bottom barrel was the fire box the second was on top of the first with a 6" stove pipe connecting the two at the back. Then at the front of the top barrel the 6" pipe went out the top. Off the top of the second barrel I had my 6" damper. From there a 45 and 80"s of pipe another 45 and out to the insulated pipe up another 20 feet. With this stove I had tones of great draft and could heat the shop in no time.

Now the problem I had with this stove was I had to replace the barrels every two years. This was not a problem till my supply of barrels dried up.

So I went out and bought a fisher wood stove mama bear. The stove had an 8" damper and top exit from the stove. I have now used this chunk of pipe with damper right off the top of the stove. After the damper I have an 8" 45 then necked down to the 6" then the 80"s of pipe (6") to another 6" 45 and out to the 6" insulated pipe.

Only difference is the stove, 8" damper, and 40"s of 8" pipe before the 6".

The problem I have is I am getting smoke out of every joint in the 6" pipe before the insulated pipe when getting the fire started. If I open the doors the smoke rolls out the doors. If I open the damper all the way the smoke comes out of every joint of the 8"-6" before the insulated pipe but I can open the doors with out smoke rolling out. In a month I was able to soot up the 6" un insulated pipe to where it was just about plugged up with creosote.

If I open up the door and try to get the stove rocking the smoke comes out of all the joints till its rocking. Then I close up the doors and crank open the air and it will back draft or back puff like a train. When the back puffs or reversion happens the smoke pours out the joints in the un insulated pipe.

All the pipe is clear I have cleaned out all the pipes. I have not had this problem before. The wood is all the same no under dry wood or over dry wood.

Only thing I can think is happening is that the heat and smoke created in this stove is filling up the 8" with much pressure. More pressure then I am getting lift in the insulated 6" pipe. If I close off the 8" damper a bit the smoke coming out of the 6" un insulated pipe is low but the burn in the stove is too.

My fix, and what I am hoping you guys can reassure me I am heading in the right direction, is to put the 8"-6" right at the 8" outlet of the stove. Right after the reducer have a 6" damper into all my 6" pipe.

I think the 8" pipe and 8" damper is not allowing me the control of the heat in the insulated chimney pipe. Its to much to fast.

Dose this make any sense? Any one ever run into this same think before?

Cheers Don.

It may be the 6" pipe not letting enough flow. If you can't get a good answer here, try posting it over here:
http://www.arboristsite.com/community/forums/firewood-heating-and-wood-burning-equipment.55/

Best place I've found for questions related to chainsaws and burning wood.

See the very odd thing is the home made stove used the 6" the same way I have it now. Just thinking that the old fisher doesn't have a internal baffle and the heat may be shooting up into the 8" to fast. The 6" has no time to heat and is being force feed the gasses. This said baffle is just before the gas has to head up the pipe. There is another baffle I use to control the gas flow in the pipe. These old fishers are great stoves but not very efficient with the wood it burns.

I think with the home made barrel stove I made there was a slow flow of gasses to the 6" through the top barrel. Top barrel was a big rad or smoke shelf.

Thanks for the link. I will do some reading.

Cheers Don.

I'm headed for bed. But I think I can give you some ideas and suggestions. I've used many double barrel stoves. I have a double barrel 55-gallon stove in my workshop.

Our main house is quite tight. The wood stove on the main floor is somewhat difficult to start. The basement wood stove is just plain defiant to get started.

All are connected to outside masonry chimneys that naturally downdraft when the outside temperature is colder than the inside temperature.

Anyway, time for bed -- with the electric blanket, two warm cats, and my bride of nearly 40 years.

DonoBBD, your draft is too cool causing that creosote build up so fast. You are going to have to find a way to get that draft faster to the outside and maintain the heat further along the line. In the olden days I had an 8" necked down to a 6" just before a turn and the pressure was too great for efficient draft. You may have to shorten your run to gain the efficiency you need. You can make anything draw if you have enough heat and enough stack height.

You should never use two size pipes, if you can get a 6" adapter coming off the stove you should be ok. 8" all the way will draw better but if your insulated pipe is 6" you have to stick with that. Your bends don't help when it comes to creosote buildup as they slow the flow of air. A tighter stove will be more difficult to draw also but will burn slower. If you have a tight stove, open the stove door a crack when starting a fire and opening a door in your building a crack will help too until you get the draft going. Make sure your chimney cap is clean and your stack should be above your roof ridge. (You probably know most of this)

My only heat source for over 10 years was a wood stove (house built c.1850). When I had a furnace installed I kept the stove for another 10 years but removed the chimney when I put a new roof on my house. I miss my stove but not the work. Steel stoves (plate or barrel) burn out in a few years as you experienced, a cast iron stove will last much much longer. The bottom grate in my cast iron stove (first place to show wear) lasted about 20 years before starting to burn out but I burned around 24+ cords a year.

24+ cords a year?

And I think 5-7 cords a year is a lot of work to cut/split/stack..............

I was thinking the same thing....dang that's a lot of wood!

LOL, I should have said 24+ face cords, that's what they really are but up here they just call them cords. So really 12+ full cords. Sorry about that!

One year we had a semi load of oak logs delivered. We cut, split and stacked it all to save some money. Seemed endless as we did it continuously to get it over with.

It sounds to me like your draft is too restricted with the smallest pipe and bends. My primary heat for my home for several decades was my wood stove and electric baseboard was the secondary source. My draft worked well but towards the end of the heating season the chimney would start to creosote up and choke the draft somewhat, then the stove would smoke with the doors open. When started a smoking stove fire I think if you prepare you wood ready to light and also put some wadded newspapers on top to create an instant heat to carry the smoke up while the wood builds up heat would help.

I have a different stove problem. I work part time in a boat repair shop. It's heated by a small wood burning stove. Anyway, we changed out the old pipe and dang near burnt the place down overnight. Where the pipe exits the shop at the wall, the wall got hot, caught on fire and then went to the roof. We're about through repairing but haven't hooked up a new pipe.

I have been told that we should have used double wall pipe. Any ideas?

Go with triple wall pipe and forget about it.

Good idea

Well I got her fixed now. It turns out that this new stove to me should have had a smoke shelf in it. This did not have any smoke shelf till today.

Here is the deal. The air comes in the two door knobs. With the fire in the stove and the exhaust stack out the top of the stove the cool air was coming into the doors some to the fire and most up the chimney. This then cooled the pipe and let the fire just smolder with little to no air. I dropped in a smoke shelf and the draft is to much.

Its really hard now not to get the stove to not chug like a train and puff smoke out the air in. She will be very very good on wood now. Just about blasted through a cord two weeks just in the shop before.

Cheers Don.

Dave, that's correct. That and keep any combustibles away from the pipe where it goes thru the wall/roof.

Loretta:

A face cord is also called a rick. A face cord is typically 4' high, 16" wide and 8' long. There are 3 face cords in a true cord. A cord of wood is 128 cubic feet of wood, stacked to minimize air space. So, you were probably burning around 8 cords of wood a year.

What were you getting charged per face cord? Here, a full cord of hardwood is around $175.

Wood is sold in all different ways, a pickup truck load, rick, face cord, etc. but the only way to know for sure what you are buying is to buy it by the cord. That's the only unit of measurement that many states recognize.

One year I got behind and bought 4 cords of wood that the guy delivered and stacked. All looked good until I started using the stack. Instead of 16" long pieces, there were a LOT of 10"-12" and 20" pieces. That left a whole lot of air space in the pile, and I doubt that I got 4 true cords. That's the last time I bought wood.

X100 - as a 10+ year veteran of the fire service I can tell you that incorrectly installed and/or poor quality installation of wood burning stoves and fireplaces are a MAJOR cause of fires. I could tell you a dozen stories in this area...bottom line, steel is a phenomenal conductor of heat, you want to make sure there is no chance for convection, conduction OR radiation to cause ignition of combustibles. That means triple wall pipe through any barrier/wall, and a clear area the entire length of the flu at least 12" if you use single wall any length of that run.

Also FYI if you install a wood burner yourself and have a fire because of it there have been cases where homeowner's insurance tries really hard not to cover the damage - better to have a certified contractor do the work if there's any question as to coverage.

+1 on that! My sister had to change homeowner insurance companies because their old one changed to "no wood burner" policy. They have one on their back porch that isn't used, but would be a PITA to remove. They bought one for the basement and had the company install it. Triple wall thru the side of the house and they have had no issues. Flue is cleaned once a year.

You would have to figure figure that out for me. My usual wood guy would bring "2 fc" at a time. When stacked in my brick building used for only for firewood it measured 4.5' high x 16' wide, pieces were supposed to be 18" long but could be 16-20". We stacked the wood tight.

You do have to be careful when buying wood. I trusted my regular wood guy, he was pretty consistent. I've been shorted by others a couple of times. One time after stacking some wood that was delivered from a new guy I was quite a bit short and the pieces were only 16" long with some shorter pieces, 12" long. I called him up and told him he needed to bring some of my money back or I was going to call the police because I didn't get what I bargained for. He brought me back some money, lol.

If the wood was cheap there was usually a reason, mixed junk species, wet (not seasoned) or shorter pieces. I preferred seasoned oak, it lasted the longest for me and smelled good. Once a fire was started in the fall the woodbox never cooled off until spring. The level of seasoning was important too. If the wood wasn't seasoned enough we would have to let the fire go completely out half way through winter to clean the chimney or it wouldn't draw well enough.

4-5 years ago I was paying $65/fc delivered for seasoned oak from my regular wood guy if I committed to at least 20 fc. He was an older retired man that became a good friend, almost like family. He had a deep vertical scar between his eyes that was caused by a chainsaw recoiling when he hit a nail years before I met him. He was lucky. I bought wood from him for many years and then his son when he became too old to do it. His son raised the price to $65 when he took over the business.

ETA: I never heard of a rick and never had anyone stack the wood for us.

Wood is sold by the rick here also. Is it a Hoosier thing?

We heat primarily with wood, and roughly go through 13-14 face a year. Never heard of a rick, other than a Rick Roll. We have electric baseboard upstairs, which normally almost never turns on except when the fire is low along with a furnace, that I have set very low as backup.

We pay $65 per face if hickory, $55 if otherwise. We clean the flu twice a year, but the stainless liner doesn't accumulate much. Since the chimney is on a single story roof, it is easy to access to clean it for me.

I have stacked the wood a couple of times when I have received it early enough. One time I made round "houses" out of it. It was a bit more work, but it was great at shedding the weather. You could roll the wheel-barrel into the middle and dump the wood in from the top, and the pile would not fall over. Obviously you leave an access hole in part of it. I saw this technique in New Hampshire and it seems to work well. Self-supporting if you lean it inwards as you build it up.

This year we may be in a bit of trouble as I have not heard back from our wood guy as I ordered late (no money, had some left overs from last year). I am also switching propane carriers as we were getting killed last year on a per-gallon cost due to not using enough (backup furnace). I don't have enough wood to make it through Christmas break, nor enough propane. The propane company ran out of tanks from new customers accepting a ridiculously good sign-up deal, so I am sweating bullets. Luckily a dead tree fell over in the woods, but that has always been hell on my back lugging that crud up a hill in the snow too deep for a 4-wheeler!

One year I neglected to stack, and we had a substantial ice storm. It glued the entire pile together with 3/4" of ice or so. That ice stuck around all winter and never melted off until I stuck the logs in the fire. I spent a lot of time chiseling ice off of wood, and smashing the pile with a sledge hammer to break it up. You would have thought I would have stacked my wood ever since, but nope.

Use a 265 gallon fuel oil tank. Six inch outlet then adapter then eight inch straight up through roof. Have had the 265 gallon tank for 5 years, no sign of failure. Try to keep 4-5 inches of ash in the bottom to protect that.

After we had our house built and I built the two story chimney so I knew it was done correctly. Also I was very careful with my wood stove and tried to be as safe as I could be. I probably over did it. I put an all slate stone floor under and around the stove. I used double insulated pipe going through the wall. Besides using a special insert going through the wall I added fiberglass and aluminum sheeting around the wall insert for an extra fire barrier. I figured this would be the weakest area for a fire to start. Then on the wall behind the stove I added sheet aluminum and then a mortared rock wall. I also clean my own chimney each year so I know it is done right. With all this I can sleep at night knowing it's pretty safe. My neighbor next door had a through the wall fire stove fire that caused a lot of damage.

Well I got her figured out. I needed a smoke shelf to hold the heat in and speed up the exhaust gas in the stove. With out the smoke shelf the smoke would turn the wrong way in the stove and with out enough speed to the the smoke would build up and roll out the doors.

Check out the video here. It will pull so hard now that it will pull sparks up the pipe. I can now slow the flame down with the dampener in the exhaust stove pipe.

This has doubled the heat out put by making the flames make a few turns in the stove and makes my load of wood last so much longer.



Cheers Don.