Creosote remedy, wood stove installation, thimble assembly.

So, I heard a “tip” from the country folks. Word is, put an aluminum can in with a hot fire, about once a month, and you’ll never have a creosote build-up problem. I tossed one in there a little while ago ’cause it was getting pretty clogged, and I did hear lots of crackling and other strange noises from the stove pipes. It sounded similar to creosote falling off when you tap the pipe. Hm!

Seems to be flowing much better now! Who knew? Probably something in the can is released when its hot enough, releasing this gas causes the flaky creosote to dislodge somehow. I’m interested in knowing more but as of right now, its a mystery until we get some chemists up in here.

wood stove burning

In other news, the wood stove is indeed installed, woo! What a great heat source; it warms objects like space heaters wish they could. We used a stove from Four Dog Stove Co., the model called the “Two dog,” as it is the smallest. Honestly probably could have used the three dog, but it doesn’t really get cold enough to need a stove that big. When the Two Dog is crankin’, full up on wood and blastin’ out smoke, it is literally way too hot in here! Good thing we have two roof vents. (The covers of which were decimating in a hail storm way back in June. I will be posting a video and blog post about replacing the covers.)


Why did we go with this stove?
-Stability during travel

Well, for one, its under 50lbs. I’m always looking to save weight in the bus (for mpg, and overall longevity.) Even a tiny cast iron stove can weight in the hundreds of pounds.

Also, I read on some skoolie forums that the cast iron ones will tend to break or “snap” if tweaked in a weird direction, whereas steel will give a little, not “snap-break” under pressure. The example of this would be an iron stove that is bolted to the floor; when driving on roads, the odd bump/pothole is hit, and in the jarring, one of the stove’s feet breaks away from a bolt. The iron will just snap under this kind of stress.

This situation doesn’t happen with the Two Dog stove; its just too light to care! The feet don’t have to be bolted at all. It scooted around a bit in travel, but suffered no damage. The pipe passing through the widow was secure enough to keep it from shifting much during travel; though it moved a little, this was not sufficient to damage to anything but a few seals. Those were easy enough to re-run; I only did the inside, and its drawing just fine. Especially with that aluminum can additive. I love the sound of creosote crackling!

I’ve had this thing cookin’ pretty good before, and its never turned “cherry red,” which can also apparently happen with the cast iron stoves. That sounds pretty scary, if you ask me. We do not have any firebrick in there, nor any sand. The Four Dog Stove Co. claims that these things are not needed, so I use the entire space for fuel. Overall, extremely pleased with this choice, as it also weighs in at about 75% cheaper than its competition at the cast iron stove stores (typically a tiny stove will run you about a grand, no kidding! And it goes up from there.)


So, for installation, the biggest problem to solve was where to pass the stove pipe through the bus. Many people suggested just drilling a hole in the ceiling, or even in the wall. I am always resistant to making holes in things, especially if they’re made of metal and happen to be my home. Instead, I decided the easiest thing to do would be to pass through an open bus window, as it was already a perfect height for it with 24″ stove pipe sections, and to fabricate what is called a “thimble,” for passing safely through the space, and insulating that opening into the outside.


The window was also an ideal choice for the bus because it already has a drip edge that follow the tops of the windows. This ensure I won’t get any leakage from rain and other weather into my thimble, or my bus.


My thimble consists of two sheets of metal, sandwiching about an inch of insulation. I used a regular ol’ coffee can to make a passage through the thimble; the stove pipe I’m using is 5″, which fits perfectly in the coffee can. This acts like “double wall” stove pipe, only its free instead of $100. Plus, you’re recycling*.You’re welcome.
*(that’s technically wrong, as its more like reusing. So that would be step 2, not step 3 of the reduce-reuse-recycle triangle.)


I used a traditional HVAC method of mating the metal sheet with the coffee can. This setup also allowed me to stabilize the stove pipe so well that I didn’t even have to take it down for travel. The option for removing this setup for the summer is there, but it isn’t necessary.

Just cut fins, then bend them in opposite directions, going around. The fins can be screwed down onto the stove pipe and the metal sheet.
(HVAC sheet metal was used. This fabrication is small enough, you might be able to buy some scraps from an HVAC shop, or have them cut dimensions for you; this stuff is difficult to cut through, much thicker than flashing.)


Try to grab the fin in a way that the tip of the pliers is where the metal will crease. I used need-nose, but if you have something long and flat enough to cover more of the fin, it would work even better. This seemed to do alright, however.


Bend one forward, then one back, and so on around your circle.
It’ll look something like this:


Now check that your coffee can fits in there nicely. You want it a little snug, its better. Anyway about it, make sure the coffee can fits!
If you’re having trouble, you can gently “hammer down” the circle where its too tight; I used my neednose pliers for this, as a hammer is almost overkill. You don’t want to overly widen the circle either! Just enough that the can will sit in the circle.


Now, to attach the coffee can to the HVAC metal. I used some 1/2″ self-tapping screws from my local farm n’ feed store. The self-tapping bit makes them a bit longer than ideal, but they are quick and accurate because they drill themselves.


Be careful not to over-tighten, as this “strips” the hole for the screw. Metal is very delicate, not like wood where you just drive it in there ‘n its good. When its almost tight, back off a lot on the drill, or even hand-tighten. It will make the pipe much sturdier to ensure the holes don’t get stripped during installation. You can even just turn the drill (while its off) as a kind of right-angle screw driver for the very last part of driving down the screw.


Kristy wants to cautiously remind you: Don’t forget to install your damper before moving on the the next part of the installation!

Damper Installation SidequestGO!!!


Set the damper on top of your first section of vertical pipe. We used 24″ length coming right out of the stove collar. Mark where each end of the damper exits the wall of the pipe. You want to make sure you go down far enough from the 90′ so that the damper can swing uninhibited. Four Dog Stoves use 5″ stovepipe.


You’ll need a drill bit to make the holes for the swing-rod. Select a size based on the diameter of the object you’re installing. You want a tight fit, but its not super critical, as you can seal it with stove pipe sealant. Ensure its at least the same size as the swing-rod.


Install it! The mechanism removes from the damping plate by compression. You push in, the spring compresses, and it allows you to turn it 180′ out of its locking tab in the damping plate. Then you slide the swing-rod out of the plate. Set the plate inside of the stove pipe (careful–easy to drop. May even be worth tying a little string on it or something if you’re doing this alone,) reinstall the swing-rod and off you go! Now you have a damper.


Okay, now its time to push the pipe through the coffee can, and hold up the interior side of our thimble so that we may attach it to the wall. This will give the thimble a lot of stability because you’re attaching the HVAC metal to the metal frame of the bus. Its held from all four sides, very strongly.


Make sure everything is seated well, all the legs of the stove are on the ground, nothing is crooked, etc. Then you can screw the remaining fins into the stove pipe, and attach all the stove pipe together. It is recommended that you put at least three screws into each connection/joint of the stove pipe. Trust me, you don’t want this stuff coming apart on you down the line!


I have already put the insulation in, here. You can see the inner section of the thimble; this is the area we will cover with our second piece of metal. Yes, it requires cutting and bending fins again! Getting plenty of experience with shears in this project.


In the bus, everything is metal. This means you have to pre-drill. Sometimes, you can get away with a high-quality “self-tapping” screw, but sometimes it just won’t do. The end dulls before it gets through the metal. Using something called “tapping fluid” or any other kind of drill bit oil will help with this. It is especially important to use this oil when using a drill bit as once you’ve dulled it, well, its dull. While it is possible to sharpen a drill bit, the tiny ones are difficult and its barely worth the effort for what you can buy one for these days–all the same, its worth keeping your tools sharp as long as possible.

Self-tappers, with weather-guard washer

Strong nail and drill bit:

Hammer + Drill, and of course, the step ladder I’m on:

I also used this nail and a hammer to make a little pre-dent for my drill bit. This ensures you get that hole drilled exactly where you’re wanting it to go. The drill bit can move around quite a bit on these hard metal surfaces.

Here is the metal underneath the drip edge I mentioned earlier. This was one reason why I chose this method and placement for installation.


I placed the upper screws as far under the drip edge as possible.


There we go! And in this shot, I’ve already started layin’ down some stove pipe sealant!


This is what I used:

Purchased Habitat for Humanity for $8 a tube. I’d hate to see what it costs retail! Really though, no complaints about it. We used it inside to stop a terrible collar leak, and its been great ever since.
I sealed all joints and seams. The stove pipe is the snap-together kind; that’s the seam I’m talking about. So far, no leaks at all.

Seal every seam, hole, or connection in the entire installation, as best you can. Inside and out, to get the best draw.


Nice one! Now we can stay warm on a Two Dog night.

Ready for fire.



3 thoughts on “Creosote remedy, wood stove installation, thimble assembly.

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