Woodstove gasketing

[redwelte]

Greetings all,

I have a Vogelsang woodstove that I have been using for about 2 years. It works well, but one of the issues I have is getting smoke in the house if I burn wet wood (sometimes it's all I can get). The chimney has to go through three 90 degree turns to get to the top, so I'm wondering if that might be a factor (which is difficult to change, as the stovepipe goes out the back of the stove, up to the heat robber & damper, then out through the wall & turns again to vertical)

I thought about some gasket stuff between the pipe joints & the elbow that comes off the stove (where most of the leaking seems to occur). I tried some Permatex hi temp car exhaust goo but it got hard & flaked off. Got too hot I guess. Then I tried some of the asbestos door seal rope glue. It worked a little better but again gave up after about a month.

I would like some suggestions if there are compounds that are better than others for this application. I have the cheap black stove pipe now, but plan to upgrade to galvanized or better, before next winter.

Thanks for your help.

[wpowokal]

High temperature silastic, but is your flue lagged? the gases may be getting too cold and depositing the Tar in the pipe, forerunner for a fire in the flue.

Is the top of the flue open with an all round cap so that wind from a certain direction can not put back pressure on the flue?

allan down under

[zeusmorg]

  It sounds as though your chimney doesn't have positive draft.

  There are many faults in installing a chimney that can cause this, the chimney top must be at least 2' above your roof height at peak, and 3' above where it exits at the roof. Also if you're exiting through a wall a long run of exterior chimney may be allowing it too cool down too much to create a positive draft. you mention 90 deg bends, horizontal runs of chimney are also unacceptable as it must have a good upflow. it's also better to use two 45 degree bends instead of one 90. Keep horizontal runs as short as practically possible and even then they must have a positive angle upwards, i'm not remembering offhand what the minimum acceptable angle is.

 You should also be using 650 Degree chimney pipe.

 You mention burning a lot of wet wood, this may be causing lower stack temperatures and causing a high rate of creosote buildup. This can block flow, but the concern with buildup is chimney fires. Which is something you wish to avoid at all costs, if you value your house and life. Chimney flu pipe should be connected with the male end on the low side, also. a draft hood over the top of the chimney pipe is also a good idea along with screening to keep out unwanted creatures. A bird's nest will block up a chimney quite effectively.

 Your heat robber may be doing it's job too well, also!

 

[vawtman]

Hi Red

 I would start planning ahead for next winter now so you don't run into the wet wood problem.

 Is your house insured?If so, get her up to code or else they may not cover you in case of fire.

 A few bucks here and there is better than a disaster later.

 Mark

[Warren]

Hello,

Do you have a source of outside air for the stove? Is there an exhaust fan running when the smoke comes in?

You may also be running the stove too cold to develop enough of a draft with the heat robber and damper in place. You could take them out and see if it improves the draft.

You do not want to get single wall galvanized pipe for the chimney. The zinc will burn off.

Warren

[MattM]

Not only will the zinc burn off but carbon is highly reactive with metal.  Failure of the pipe is imminent.  I wouldn't even recommend using galvanized pipe in a pinch.  We all know how temporary soon becomes permanent...

[elvin1949]

redwelte

 I agree with most of what has been said already.

That said DO NOT use single wall pipe outside the heated area.It WILL stop up.

 I use triple wall air insulated stainless stove pipe on my system.It holds the heat in the pipe so you will have a good draft. Do not put a damper in the stove pipe,use the damper on the stove.

 My system is 25 years old and i never get over 2 cups of soot at clean out time [Every fall].

 I do have to clean the spark arrester about once a month. [Hot flue gases hitting cold air condense out.5 min. with a wire brush its clean.]

 Better safe than homeless.

later

Elvin

[SteveCH]

I agree with the others who've answered before me. If there's a way to change any of the 90 deg. stuff to a couple of 45's, that'll help. A little. The "wet" wood is a problem. Less BTU output, poorer draft, more creosote. However, perhaps that is just what you must work with.

After ten yr. of using the inexpensive black pipe, I installed the double-walled, insulated stainless. It is pricey. And the "accessories" [caps, etc.] are as well, and the regular ol' sheet metal stuff won't fit. It is heavy, so must be supported. My outdoor portion of the pipe is tall and I've got it secured by guy wires for wind protection.

The sections lock together in a screw-type motion, so that would probably cure the smoking indoors.

Around here, the only places to get this stuff is through building supply companies, and not your quintessential big-box supposedly discount chains. That means more money.

However, we've been using ours for around 25 yr. and so far there is no problem. The cost made me gulp, but I've had very little maintenance on it since installation. With the black pipe, I had to clean it out a couple times a winter and replace various sections every couple years.

But you need to think hard about some way to alter the pipe run, in your case, if at all possible. Maybe a 45 to the section thru the wall, then another 45 to transition back to vertical. If you can get rid of those 90's, it'll be a start. If you get smoke back in the house, you are also certainly getting carbon monoxide.

[jonas302]

after buying insulated pipe from my heating guy I found it on ebay for a fraction of the cost so check there if you go that route and if you want it to flow good get rid of the stack robber they kick out a lot of heat but I had to replace stovepipe every year because of the cool gasses and corrosion

[TomW]

jonas;



I had to replace stovepipe every year because of the cool gasses and corrosion

About 10 years ago, I switched from heavy gage painted steel pipe to stainless steel pipe from stove to masonry chimney.

Now, rather than getting 2 or 3 years from a pipe I am getting what looks like it will be 20+ years on the SS pipe.

Mine looks pretty much as good as it did the day I installed it. Slight blueing but structurally 100%

I think it is well worth the cost. It will also stand up to a stack fire without collapsing.

Spend $50 once or spend $15 6 or 7 times its a no brainer.

Just my experience.

TomW

[redwelte]

Thanks to all for your great comments & personal experiences. A couple of things I have done: I drilled a hole through the floor (I live in a yurt, on pier & beam) & stuck a 2inch PVC pipe directly to the outside. That made a large difference: it is a demand system air supply. When the stove is going, the outside air draws directly into the stove damper, when the stove is off, then very little air flows. Kinda makes me wonder where the air was coming from previously... The stove is much more efficient using the outside air pipe: I can shut the damper on the stove all the way down & still have it not toasty, but HOT, inside.

I will also look into using 2 45 degree elbows rather than the 3 90's. But I have to go through the side of the wall rather than the ceiling (leaks & so on).

I found a small pile of last year's wood so used it as an experiment. It was a lot hotter than the wet stuff I've been struggling with. I will begin laying in wood very shortly, in order to have some good dry stuff for next winter.

I clean my chimney every 2 or 3 weeks just to be on the safe side. There sure is a lot of baked on stuff that comes out!!

I will also look into the multi walled stove pipe, as suggested by some.

After a winter of the heat robber going off at 2AM & waking me up, I think I might also try using the stove without it...

All sorts of good ideas.

Best regards to one & all.

Redwelte

[TimV]

You basicly took the words right out of my mouth....If you want "forever more" get stainless pipe it is available but not cheap but it lasts.