Cleaning Outbacker Stove pipes?

Dan1982

Full Member
Jan 14, 2006
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Cumbria
Afternoon all! I’ve just been away in the tipi for the last 5 days and by outbacker stove pipes are CAKED inside with thick tarry sticky soot. This isn’t something I’ve experienced before and they were basically clean when I set up. I did use a little bit of slightly under seasoned wood but it was primarily shop bought “kiln dried” birch stuff on this trip.

Can anybody recommend a good way to clean this? It’s literally like birch tar!!

Thanks

Dan
 

British Red

M.A.B (Mad About Bushcraft)
Dec 30, 2005
26,887
2,140
Mercia
Afternoon all! I’ve just been away in the tipi for the last 5 days and by outbacker stove pipes are CAKED inside with thick tarry sticky soot. This isn’t something I’ve experienced before and they were basically clean when I set up. I did use a little bit of slightly under seasoned wood but it was primarily shop bought “kiln dried” birch stuff on this trip.

Can anybody recommend a good way to clean this? It’s literally like birch tar!!

Thanks

Dan
Hi Dan, what's the inner diameter of the pipe ( in inches)? There should be a good option available. I have a number of flue cleaning tools - just considering which will work best
 

Dan1982

Full Member
Jan 14, 2006
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Cumbria
Hi Dan, what's the inner diameter of the pipe ( in inches)? There should be a good option available. I have a number of flue cleaning tools - just considering which will work best
Hi Red, hope you’re well matey. Thanks for your reply, I don’t have callipers but I measure at 2.1” inside diameter.. it’s hard to tell with the amount of tar!

What would you recommend??

Cheers

Dan
 

Dan1982

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Jan 14, 2006
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Cumbria
A large bottle brush or something like. Birch bark is a known culprit for sticky soot.
I feel something a little more aggressive may be required unfortunately….. I’m considering and old carving gauge to scrape it all off.

Flip side, I’m strangely growling fond of the smell… every cloud!
 

Nice65

Brilliant!
Apr 16, 2009
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Something like this? And a tub of solvent. The brushes can be attached to extensions. There might even be ones that’ll fit into a drill chuck.

 

British Red

M.A.B (Mad About Bushcraft)
Dec 30, 2005
26,887
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Mercia
Hi Red, hope you’re well matey. Thanks for your reply, I don’t have callipers but I measure at 2.1” inside diameter.. it’s hard to tell with the amount of tar!

What would you recommend??

Cheers

Dan
Dan, for lined flues & piped, I use flexible rods with a loose brush on the end. The end rod goes into my drill and it spins fast dislodging soot and creosote. Those brushes are usually 4" to 6" in diameter. I don't see why you couldn't do the same with something like this

 

TLM

Bushcrafter (boy, I've got a lot to say!)
Nov 16, 2019
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Vantaa, Finland
I feel something a little more aggressive may be required unfortunately
Depends on what kind of brush you find, sometimes it does take some scraping. High resin pine sometimes causes the same problem.

I have always assumed it is the high wax content in birch bark that causes the problem, Robson Valley might know more.
 

birchwood

Nomad
Sep 6, 2011
461
108
Kent
I have a wire brush on a stick, the brush head is 2” wide and 2” long, sort of fan shaped. Has a double twisted wire handle about 9” long.
I have an Ozpig stove and the chimney sections are not that long so just work from both ends and spin it round.
Can’t do pictures unfortunately so you will have to use your imagination.
 

Erbswurst

Bushcrafter (boy, I've got a lot to say!)
Mar 5, 2018
4,079
1,774
Berlin
Did you try to scratch it with a straight branch? Just push the tar through!

If I get such problems it works for me and afterwards I burn out the rest of it with the most possible heat.
 

Mesquite

It is what it is.
Mar 5, 2008
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~Hemel Hempstead~
If they're single skinned flue pipe then build a nice hot campfire put the pipes in it and let the tar burn off. What's left will either flake off or be easier to scrape out as it's not as sticky as before
 
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baggins

Full Member
Apr 20, 2005
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Once you've gotten them clean, i just use a cheapo toilet brush after every 2 or 3 burns. Stops the build up of tar. Also, what wood are you burning? Green wood or High tar type woods such as conifer are more likely to soot up the narrow chimneys of tent stoves. Maybe modify the wood type you burn if you can.
 

Robson Valley

On a new journey
Nov 24, 2014
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McBride, BC
I suspect you liked to have the stove damped right down, not much above smoldering. Those little stoves chill out (surface area/volume) far faster than a much bigger stove like and AirTite. Your chimney was cool to the top and the wood oils as smoke condensed all over the insides of everything.

Mesquite has the right idea = you are going to have to burn this out. Birch tar is very hard to vaporize, particularly from less that bone-dry wood. Leaving the bark on may look pretty but now you pay the consequences for it.
Plan B: Have one hell of a hot fire to get the tar volatile and smoke that out. No twigs, no bark, just cabinet work shop offcuts for HEAT.
Plan C: Do nothing. Promise yourself to have many more really hot fires from now on. You do have bragging rights. Obviously, you have made many fires in your stove. I hope that you make many, many more.
 
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