Decoking the Stove

[Plain Peter P.]

A condition of the house insurance that we carry requires that the chimney above the woodstove in the large living room be cleaned periodically. This is to minimize the probability of a chimney fire at the very worst time of the year. In January or in February, when every damn drop of water within a hundred miles is frozen solid, except what we draw from the well, a chimney fire might have us running around outside in the snow in pajamas without a cell phone or a clear idea of who to call... Not a nice thought to entertain.

This year in nice weather I figured I would not only clean the chimney, I would junk out the stove as well. The evil chimney was easy: twenty-five bucks worth of brush and connectible fiberglass rods was a good investment some years ago. Everything screws together, nothing to break, scrub-scrub-scrub, big plastic bag, shopvac half full of crap - all takes less than an hour. Put away all the stuff, dump out the vac drum, rinse out the filter, another half hour.

Just for the hell of seeing it, I lay on my back under the pipe and looked up. Nice and bright. As clean as a Christian conscience.

The move of the stove needs more thinking. The thing weighs probably near three hundred pounds. Before I had pasted in a lining of firebrick, it was carry-able. Afterward, nowadays, it is only walkable out through the front door on a couple of slabs of plywood to protect the flooring on the way. That takes a while. Just myself. I chased every other live thing out of there. I didn’t want a whole lot of discussion of how and why.

Outside, the task is to relieve this monster of all the baked-on gubbins of the last who-knows-how-long of burning cordwood. There is a lot of it. And, with a couple of cheap wire brushes and a scraper and a nice sunny day, it takes a while. But it doesn’t ask much from my mind. So, chip-chip-chip, I get to thinking about decoking generally.

Throughout the early decades, up until about the 1960s, motorcycle engines, cars too probably, needed decoking. It was rare for a motor to go more than about twenty or thirty thousand without a teardown. To remove the junk. Petroleum technology being what it then was, lube oils were pissy imitations of what we use now. Hydrocarbons were chancy. Metallurgy was likewise sort of Made in Taiwan. (Taiwan wasn’t Taiwan then, it was Formosa.) Motors would routinely need new rings and a valve grind at the same time as this biennial decoke. Valve springs would get sloppy and unpredictable. Does ‘valve float’ still happen? It happened quite low down on the rev counter … er, tachometer … back then.

The only time I have heard lately about someone doing a decoke was on a hard-used race bike. And that, it seems to me, might have been counter productive. Tell me why? Carbon pasted on to the interior surfaces of the combustion area will bump up the compression (to some precisely immeasurable extent). It seems unlikely that a motor
running for most of the time at near maximum load would suffer from pre-ignition, running-on, or bad starting. Which were the stated reasons back then why bikes had to have regular decokes.

A copy of The Motorcycle in about 1953 carried an article about a Vincent V-twin whose owner had ridden it a hundred thousand miles without a decoke. (But with many ‘tyres’, chains and sprockets changed.) Amazing! No bike could do that. But if any could, a Vincent could. And nobody - I was an apprentice in those days - except a rich kid could afford all those parts.

I think of all the reports which nowadays are often heard and taken for granted: bikes which have run over two hundred thousand miles without serious mechanical intervention. And no decokes. The guy in California whose Gold Wing is into its fourth hundred thousand. (He changed the water pump and a stator.) I think of how much better value for money bikes generally are now. I think about how it would have been great to be born fifty years later. NO, I TAKE THAT BACK: let’s keep things the way they are…

This stove has had enough of decoking. With most of the afternoon gone, I wire brush the outside with an angle grinder. Then I wash it down with solvent and three of my T-shirts, and lay on a coat of manifold paint. Sixty bucks for an American pint. Battleship grey. Its metal hot from the sun, the solvent blows away and the paint dries in an hour.

Tonight I’ll fire it up outside with coal in it. Hot. Tomorrow, it’ll be cool enough to walk it back in. The provenance of this piece of primitive engineering is, as far as I can discover, that it came from Montreal to Alberta sometime in about the late 1940s. The top casting has Warm Morning embossed on it. With an overhead fan running slow and blowing down, the heat will make its way into all of the upper floor of the house. When the temperature outside is minus thirty, I will decide again whether decoking was a good idea.

[Plain Peter P.]

The above will piss off some who are bike fundamentalists. Also some one-word posters. It keeps my brain alive to write some words now and then. You don't have to read it.

Uwe, I can't get the Italics to work. Likewise, I can't dick around with font sizes. This site is slick, compared to the rust-bucket it used to be. But it needs some tweeking here and there...

Best regards.

[TimP]

Dear Peter,

Please continue "(keeping your) brain alive". It keeps mine alive, too.

[RickO]

As a fettler of old British bikes for a few years as well as a burner of wood in three previous houses, I can see some connections here.

As nice as the stove you are nursing along probably looks, it sounds like it belongs on display beside my old Norton. Modern air-tight stoves are light years ahead of the old cast iron models. The last stove I had was a Cartier, built in Quebec where they also know about cold. It was welded steel construction with a removable firebrick lining. It featured a secondary combustion chamber at the top of the main firebox formed by a tightly-fitted layer of firebrick directly above the fire.

Two additional necessities are a glass window in the door -- which allows inspection of the fire without opening the door -- and a probe-style stack thermometer in the double-wall smoke pipe about a metre above the stove.

When starting the fire (nice dry hardwood, of course) a damper at the back of the firebox is opened, allowing smoke to travel straight up the stack from the back of the firebox. Once a good draft is established, stack temperature starts to rise. When the thermometer shows 500F (just above the magic 451F kindling temperature of wood products) and the glass in the door clears you are almost in business. A peak through the glass up at the bottom of the firebricks forming the secondary combustion chamber should show the firebrick free of soot and beginning to turn white. At this point the damper at the back of the firebox is closed and smoke from the firebox is forced to the front of the firebox and up through a port where it is has to double back over the hot firebrick at the top of the firebox and through the two-inch high space that forms the secondary combustion chamber. Fresh air from an adjustable outside duct is injected at this point, causing the smoke itself to burn. Stack temperature quickly climbs to 1100F. A visual check of the top of the chimney outside shows just heat waves rising -- no visible smoke. Inside of the stack and stove remain "coke-free".

Modern bikes feature precise air and fuel control and may even include a catalytic converter that acts as an "afterburner". The results are better performance from a smaller engine along with cleaner combustion and better fuel economy. Modern 600cc sport bike engines are at the same hp/litre ratings as Formula 1 cars of a few years ago.

One reason that wood stoves plug up is that people often have a stove two or three times bigger than necessary to heat their house and it ends up "idling" with a slow, smokey fire most of the time. It is better to use a smaller stove and run it "wide open". It will stay cleaner. Modern bike engines like to be revved too, and will perform better at a steady, high rpm rather than being "lugged".

[metalredneck]

"Coking" has been replaced with "Those gummy deposits in your injectors & on your valves". I work at a GM dealer and see this crap every day. For a while, it wasn't so bad, but when gas hit the magic $1 per litre, we saw a dramatic increase, due to poor fuel, and people choosing to use poor fuel. Garbage in, garbage out.

Keep writing, PPP, on topic or not. Refreshing comes in many flavours.;)

PS: Are you burning birch out in L.A., or poplar? I hafta say, the maple out here lasts all night. Unlike me.:confused::mad:

[Plain Peter P.]

to Rick for the education,
to MRN for the encouragement, see 'Your Notifications',
to TimP for being TimP.

[KZDon]

As a fettler of old British bikes for a few years as well as a burner of wood in three previous houses, I can see some connections here.

As nice as the stove you are nursing along probably looks, it sounds like it belongs on display beside my old Norton. Modern air-tight stoves are light years ahead of the old cast iron models. The last stove I had was a Cartier, built in Quebec where they also know about cold. It was welded steel construction with a removable firebrick lining. It featured a secondary combustion chamber at the top of the main firebox formed by a tightly-fitted layer of firebrick directly above the fire.

Two additional necessities are a glass window in the door -- which allows inspection of the fire without opening the door -- and a probe-style stack thermometer in the double-wall smoke pipe about a metre above the stove.

When starting the fire (nice dry hardwood, of course) a damper at the back of the firebox is opened, allowing smoke to travel straight up the stack from the back of the firebox. Once a good draft is established, stack temperature starts to rise. When the thermometer shows 500F (just above the magic 451F kindling temperature of wood products) and the glass in the door clears you are almost in business. A peak through the glass up at the bottom of the firebricks forming the secondary combustion chamber should show the firebrick free of soot and beginning to turn white. At this point the damper at the back of the firebox is closed and smoke from the firebox is forced to the front of the firebox and up through a port where it is has to double back over the hot firebrick at the top of the firebox and through the two-inch high space that forms the secondary combustion chamber. Fresh air from an adjustable outside duct is injected at this point, causing the smoke itself to burn. Stack temperature quickly climbs to 1100F. A visual check of the top of the chimney outside shows just heat waves rising -- no visible smoke. Inside of the stack and stove remain "coke-free".

Modern bikes feature precise air and fuel control and may even include a catalytic converter that acts as an "afterburner". The results are better performance from a smaller engine along with cleaner combustion and better fuel economy. Modern 600cc sport bike engines are at the same hp/litre ratings as Formula 1 cars of a few years ago.

One reason that wood stoves plug up is that people often have a stove two or three times bigger than necessary to heat their house and it ends up "idling" with a slow, smokey fire most of the time. It is better to use a smaller stove and run it "wide open". It will stay cleaner. Modern bike engines like to be revved too, and will perform better at a steady, high rpm rather than being "lugged".

Ah. Kevin Cameron of the wood-energy set.

Good and interesting writing one and all, especially considering the rushing feeling toward snow and cold.

It used to be my job, around March break every year, at my grandparents' farm, to remove all the stovepipes from the big white-enamel stove in the kitchen. It was a lot of fun to set the individual sections on the snow covered driveway, stuff them with some newspaper, then light them up to burn out the creosote.

Sitting in the old black leather tub chair next to that stove was one of the best things ever. Grandma always had a kettle kept warm on it, that acted, I learned many years later, as a humidifier, but was always ready to boil up for tea, coffee, gravy (mmmm!!!) cleaning the milk/cream separator, thawing the pump, or other fun boiling water pasttimes.

[Hayabusa]

Big diesels used in ships still require decoking. Apparently...

[Plain Peter P.]

Peter,
I thoroughly enjoyed "Decoking the Stove" on at least two levels. To begin with, it combines meditative and practical elements, colour and readability. On the second level, it struck a deeply resonant chord: I remember as though it were yesterday "running around in the snow in pajamas" while our house on the outskirts of Steinbach, Manitoba burned to the ground during the winter of 1962. I was seven, the morning fire began at the chimney of the kitchen woodstove that was the sole source of heat for our house, and it was bitterly cold the whole winter (or so it seemed to me).


However, (and here's the shame) the story has already appeared on the Cycle Canada forum. Unfortunately this qualifies as a piece that has been previously published by our number one competitor. I realize that forum content has a slightly different context, still I must respectfully decline. I would most certainly have published the story otherwise. It's excellent. Actually, I wonder if it might be worthwhile pitching "Decoking" to Canadian Geographic. They have a back-of-book department called "In Habitat" to which your essay seems well suited.


Let me reiterate one point: the charm of "Decoking" is that it combines the mediative with the practical. By this I mean you've created a subtext that speaks to the seduction, and the folly, of nostalgic deliberations ("No, I take that back: let's keep things the way they are ...") yet the message is delivered in an illustrative essay supported by hard, crunchy detail: ("Then I wash it down with solvent ...").


There's short story by the American writer Scott Russell Sanders called "The Inheritance of Tools" in which the author explores the significance of family through the medium of carpentry tools handed down father-to-son over four generations. He wrote: "My grandfather used to cut down hickory trees on his farm, saw them into slabs, cure the planks in his hayloft, and carve handles with a drawknife. The grain in hickory is crooked and knotty, and therefore rough, hard to split, like the grain in the two men who owned this hammer before me."


Decoking triggered my memory of that story, and, in my view, it's the Sanders style of writing that you are experimenting with. I would encourage you to continue exploring that vein.


All the best,
John




John Campbell
Editor

Canadian Biker Magazine

edit@canadianbiker.com

www.canadianbiker.com

[Plain Peter P.]

John, that was about the nicest letter I could have had from anyone, short of news that I had won the lottery. Very encouraging, good for my ego and a nice birthday present. Thankyou. I will reprint it (the letter) on that same forum with your permission. Some of my buddies there will take an interest. I will also round up whatever has been written by Scott Russel Sanders and get into a study of that. Should auld aquaintance be forgot.... Peter P.

[KZDon]

It would probably do well in Cottage Life too...unless, of course, Harrowsmith is still being published...

[TimP]

It would probably do well in Cottage Life too...unless, of course, Harrowsmith is still being published...

It is. So is "Hooking" (or something like that about rugs). My wife gets them all. Dog mags, too.

Not sure how the dog mags would taker to the decoking story, Mr. P., but the others are definitely worth a shot.

[Ivor biggin]

It is. So is "Hooking" My wife gets them all.

Plain envelope?
I.B.

[TimP]

Eco-friendly brown wrapper.

Lots of phone calls after 10, too. Weird.

[Neil Graham]

Peter,

I've had a few friends who've needed to be decoked, but now they're clean and carrying on with their lives. If they relapse I'll send them west to you. Wonderful piece, though, please send it to our editor with my encouragement. Happy birthday, too, I can only hope that I'll be as cantankerous should I make it to your age.

Regards, Neil Graham

[Kootenanny]

A well-written piece.

In connection with RickO's comments on the contrast between old and new technologies, I will have to say I recently installed a "newfangled" heat system to my home, a Ductless Air Source Heat Pump. These units are common in other parts of the world, but not here in North America--especially not here in the Great White North. However, the most modern ASHP technology now allows heat to be pumped even during very cold weather (-34 C, anyone?). Mine is rated down to -18 C. We'll see how it works.

The thing is, even with this gleaming piece of ultra-high-tech technological wizardry installed, I'd still like to install a woodstove in my home. Not only will this ensure that the house will remain warm and comfortable during the coldest weather (I do have my concerns about the ASHP...), but there is a certain, undefineable cachet that comes from wood heat. The stove doesn't have to be, or even look, antique--I prefer the sleek, modern designs myself--it's just that a wood fire in the home seems to be part of the Canadian consciousness. Especially a rural home like mine.

However, when I do go shopping, I'll stick with the more modern burn chambers, thanks. Decoking? Uh, hopefully not...

[Ivor biggin]

Before moving to Canada in 1980 I lived in a mining town in the north east of England and at that time nearly every home in the community had a coal fire. I could go on with this but I`d rather reminisce about scraping diamond hard carbon off the aluminium, notice the spelling, cylinder head and piston crowns of my Triumph T100. These deposits were supposed to be removed with a hardwood scraper but I think that most people, like me, reverted to something a bit harder. Like a knife or a screwdriver. Of course, after the soft aluminium had been attacked by steel, the gouged and scared parts had to be lovingly polished before reassembly. You`ve never lived if you havn`t sat at the kitchen table shining up pistons on a Friday night while the wife bathed the kids and got them ready for bed. They were the good old days when you could tell a motorcyclist by the crud under his fingernails and by the fact that his wife wasn`t speaking to him on Saturday morning.
My story about cleaning the sludge out of a pair of Ariel Arrow silencers is best left untold.
I.B.

[Hayabusa]

...Stack temperature quickly climbs to 1100F. A visual check of the top of the chimney outside shows just heat waves rising -- no visible smoke...

That's pretty damned hot!

To put it into perspective, the Sun is generally the hottest object we think of. The surface of the Sun is believed to be just under 5800° K (9940.73° F).

That's only 1/9 the surface temp of the Sun, however the Sun is a hydrogen gas star undergoing constant nuclear fusion whereas the 1100° F in question results from burning wood, in a chamber in your living room...:D.

That's just how my mind works...:o

[Plain Peter P.]

>Wonderful piece ... please send it to our editor with my encouragement.<

Will do. Have done. I owe you.

[Plain Peter P.]

You said a mining town on the northeast coast. I'm guessing Sunderland or Newcastle. My wife is a Geordie. From Swalwell. When she's having a second drink, I can't make out a word she's saying...

You write a nice yarn. Please tell us about the Ariel Arrow silencers. The crud under the fingernails left me a bit damp-eyed.

Geordie bumper sticker: Divven dunshus mar, war Geordies!

[Ivor biggin]

You said a mining town on the northeast coast. I'm guessing Sunderland or Newcastle.[/I]

Close Peter but we don`t mention Sunderland in polite company. Actually I`m from Ashington, a town of 30,000 gentle souls in the Kingdom of Northumberland that survived my leaving and the ravages of Maggie Thatcher. Now I would love to know how the hell you managed to capture the heart of a sweet geordie lass.
By the way, for anyone who doesn`t know that part of the world, Northumberland is inhabited by hoards of insane 250 riders who enjoy terrorising and humiliating any rider on a big bike who is foolish enough to venture away from the main roads.
I.B.

[Sidecar Bob]

When we moved to the place in Beaverton the only firewood I could find for sale in January was offcuts of 6" x 12" kiln dried pine from a place that built log cabins. It At temps below -20 it made a rather satisfying and musical sound like breaking glass - not the crash of a shattering window, but the "tink" of a glass cutter making a clean cut. I think it was the resin frozen inside the wood.
Never having had anything to do with a fireplace before, I did some reading, lined the fireplace with fire brick and bought a glass door for the fireplace to improve combustion and improve the ratio of heat produced to heat lost up the chimney.
I also learned that Pine wouldn't work the same in the fireplace as hardwood. To get the most out of it I had to light the fire as soon as I got up in the morning and let it burn really hot until the stones of the fireplace were hot to the touch and then let the fire go out (actually a fairly quick process if you are burning kiln dried pine) and close the vent & damper. The "thermal mass" of the pebble stone fireplace would continue to give off heat for 8-10 hours after that. I would do the same thing again in the evening and it would still be warm in the morning.
The next fall, when we called the chimney sweep in again, he looked at it and said "You have to pay me for coming out anyway, so I might as well sweep it, but it's pretty clean now."
The short, hot fires had kept anything from building up.

In later years, when we were burning hardwood from the trees we had cut down when we built the garage, we had to do the usual cooler, longer fires and keep it damped down overnight so the stones would still be warm in the morning, we also had the normal deposits in the chimney that had to be cleaned out every year.

BTW: The CX/GL500/650 Web resource has a page about decoking your engine, so I guess it is still common practice over there.
It must be the quality of the fuel - I just did the head gaskets on my '84 650 (I'm changing all of the gaskets in an effort to make it stop leaking like a HD wannabe) and the thin layer of carbon on the pistons & in the heads was easier to get off than the gasket sealant the last guy used.

Oh, and I have crud under my fingernails too these days. And black rings around their edges.