The Cubic Mini is a teeny-tiny wood burning stove built for small spaces — tiny homes, vans, RVs, and yes, even boats. It’s one of those products that we probably spotted on Instagram. At any rate, we had it picked out before we picked out our boat. It is, in a word, cute.
Like so many things, the Cubic Mini is a stellar product, but it is certainly not for every boater. Here’s a look in detail at how this heater has worked out for us after six seasons of use, with the good and the bad.
What Is the Cubic Mini? And Why?
The Cubic Mini is a new brand of wood burning stove built for small living spaces. I’ve seen pictures of them in tiny homes, vans, campers, and other boats.
The Cubic Mini comes in two sizes: Cub and Grizzly wood stove. They are both very small, but the Grizzly is just slightly less small. The Cub is marketed as 14,000 BTU, while the Grizzly is 18,000 BTUs of heat output.
Even though it might sound ridiculous to some (and boy, we have gotten some looks!), operating a wood-burning stove on board a boat is nothing new or novel. So long as it is properly installed and has a marine flue fitting that protects your wood and fiberglass, you should be just fine. There are marine solid wood stoves that do the same thing, like those made by Dickensen.
Of course, it requires careful monitoring and operation. Personally, I would never operate it while underway, and I would never leave it unattended.
The Cubic Mini Installation on a Boat
Installing anything on a boat means doing homework and looking at various possible installation options. Remember, the Cubic Mini is not designed explicitly for boats — it’s just been installed on many of them. There’s nothing wrong with that, but don’t expect the company to provide every part you need (or know that much about how to do it).
Here are the parts we bought for our installation:
From Cubic Mini:
- Cubic Mini Cub wood stove
- Stainless steel wall mount
- 2x 24″ sections of double-wall 3-inch flue pipe (sold by Cubic Mini, you cannot use other brands, length depends on your installation)
- Cubic Mini matching miniature tool kit
From Defender or marine supply store:
- Charlie Noble deck fitting — Dickensen marine through-deck chimney exhaust fitting 3″
- Dickensen Round chimney cap 3″
- Dickensen H-style chimney cap 3″ (for high winds)
- Dickensen rain chimney cap 3″
From Amazon or a hardware store:
- Fire extinguishers, smoke alarms, and CO detectors (hopefully already on board as part of your safety scheme and new boat outfitting!)
- Grill lighters
- Generic stove-top heat fan
- Wood stove temperature gauge
- 5-inch hole saw for cutting through the deck
- Thickened epoxy filler (i.e., West System Six10 or TotalBoat Thixo) for ‘potting’ installation hole
- Teak blocks to make the fitting sit flat on the deck
- Teak trim for interior fit-and-finish
- Stainless screws + sealant for deck fitting
- Ryobi cordless mini-chainsaw or sawzall for cutting wood
Using the Cubic Mini: A How-To Guide for Beginners
We had a bit of a learning curve with our Cubic Mini because neither of us had ever operated a wood stove. Like building your first campfire or lighting a fireplace, it seems easy until you try to do it! Even if you have experience with a wood stove, we’ve found that the tiny size of this one makes it unforgiving of errors. Slight differences in fuel, draft, and damper settings make significant differences in the temperature and length of burn.
What follows are some tips we’ve learned from doing. But start by reviewing all of the documentation that comes with your stove. No matter what, there will be some trial and error as part of the process.
Installing the Cubic Mini Wood Stove on a Boat
Like many things on the boat, where you put the stove will depend on many factors.
The first thing to think about is the flue and chimney piping. Ideally, it should be kept completely vertical. On a sailboat, you’ll want to make sure the chimney caps aren’t somewhere that will get tangled in lines every time you sail. The hole for the chimney is huge, five inches in diameter. So you’ve got to have that much space to cut out, plus room for the flange of the through-deck exhaust fitting.
Of course, the location you pick also has to work with your interior layout. Boats don’t have a lot of wall space for this sort of thing. The wall space you do have might not be ideal for a heating appliance.
If you look at our installation, you’ll see that it blocks the traffic flow a bit. I was concerned about this enough to bolt the stove onto the wall on a trial basis to ensure we didn’t bang our knees on it. It works fine, but is definitely in the way and taking up space. In all other respects, it’s the perfect place, so that’s where it stayed.
You also want the stove at the right height. Too close to the ceiling, and you won’t get any hot air at the cabin’s sole. Ours is waist-high, and it works fine.
Fuel for the Cubic Mini Wood Stove on a Boat
The first challenge for us was figuring out how to readily get fuel for the stove. Sometimes, we’re in rural areas with woodlands where we can find natural wood. But other times we’re in the city, or protected areas, with no hope of collecting our firewood.
We are hesitant to carry a lot of firewood on board because we don’t want to bring bugs into the boat. We found numerous references to people using pressed sawdust logs and commercially available fire logs, but in our experience, only one type works in wood stoves. More on that in a moment.
A woodworking friend who is obsessed with our tiny stove gifted us a bunch of wood for it. He has a shop, often with tons of wood lying around and a table saw to cut it. He kindly sawed us a bunch of the world’s cutest logs, dried and perfect for burning, of cherry and cedar. They were the ultimate fuel and worked great, but we had to develop a more sustainable approach than the friend-gift system, especially since we travel far from this friend most of the time!
Lighting the wood is another challenge. Ultimately, we found that using commercial fire starters was the best. Ideally, we like the Royal Oak Tumbleweeds (available at Walmart), which are just bunches of thin wood strips soaked in a wax that burns for a long time. They’re sold to help light charcoal grills without chemicals.
I bought a small hatchet with the idea that I could use this to either chop deadwood in the forest or dried store-bought firewood. It was a complete disaster — it’s impossible to do much of anything with a small camping hatchet. A full-on axe would be better, but I didn’t want to carry that around. A friend gifted me a Ryobi sawzall (reciprocating saw), which he wasn’t using. It matched the Ryobi batteries I already had, and they make some long, coarse-toothed blades that do well cutting wood down quickly. It’s slow, though, and I think a little battery chainsaw (or chair pruner) would be the best solution.
When I’m walking around wooded areas, I’m now always on the lookout for the perfect downed trees. For the Cubic Mini, the ideal branches are between one and four inches in diameter and cut into four to six-inch-long sections. You want to look for the tree or branch that died a while ago and fell, but it’s not lying on the ground and rotting. That will give you the most dried-out, long-burning wood. I avoid pine, although it works in a pinch. Hardwoods are always better.
But cutting our own wood doesn’t always work out, so we also keep some of those store-bought fire logs around, too. When shopping, you must read each package because most say “not for use in wood stoves. The only exception we’ve found are Enviro-Logs, which are often available at Walmart. A box of six logs costs about $23, enough for about 20 fires. They’re just wax paperboard scraps, like old cereal boxes, pressed together into a log shape.
You have to cut the Enviro-Logs into quarters to fit in the stove. They last the longest if you cut them cleanly without breaking them apart. You can do it with a good bread knife. I’ve also just torn them apart by hand, which is faster. The results are messier and they burn quicker, however.
The Enviro-Logs work great as fire starters, too — they quickly get the stove up to temperature and never fail to light. They’re about the easiest, least fuss fuel we’ve found. My favorite mix now is to start the fire with a quarter of an Enviro-Log and one or two hardwood pieces. Then, you can just add more hardwood as the fire burns.
Drafts and Backdrafts
Any heating appliance requires creating a draft — constant airflow in the form of hot air rising out of the appliance and leaving through the chimney must be supplied with fresh air from somewhere else. If not enough fresh air feeds the fire, outside wind will come down the chimney, smother the fire, and fill the boat with smoke. That’s called a backdraft. No bueno.
The first problem we had was supplying enough air. Boats are much more air-tight than you might think. Our boat has two dorades in the main cabin, and I believed (incorrectly) that these would allow enough air to feed the fire. I now always open one of our small portlights up near the V-berth. This hasn’t failed me yet, even in very windy conditions. It seems nonsensical, letting cold air pour in through the open portlight when you’re freezing. But thankfully, this particular portlight is small and does not channel much wind into the boat, so it does not cool it off that much.
The next problem is that the stove was tough to light. If there was any wind, it was hard to start the draft. Strong gusts of wind would backdraft. We switched to the H-style chimney cap, and that problem is almost completely solved. The marine round chimney cap is sexier, but it doesn’t work if there’s any wind at all.
Getting a Fire Going with the Cubic Mini
So, with the H-cap installed and the small portlight open, we are ready to get in business. If there’s ash left in the stove, I clean it out. I also usually scrape the glass window clean with a razor blade scraper. Cubic Mini recommends cleaning it with ash from the stove on a paper towel, but I never had much luck doing that. I also sit my heat fan on the stove top, aimed where I want it (the far side of the salon, or down the hall toward the V-berth).
Then, we load the stove with a quarter of an Envirolog and a few pieces of hardwood, if we have them. If we have no hardwood, we use a third of an Envirolog at a time. We light the bottom corner of the Envirolog to get it going.
We open the primary damper completely (full right) and the secondary damper is closed completely (in all the way), and we leave the door open a little until the fire is burning well. With the door closed, the fan starts spinning in about five minutes. Once the fan is spinning, we close the primary damper until it’s only about a third the way open, and we open the secondary damper about a quarter of the way.
For the Envirologs, this seems to be about the perfect setting every time. Hardwoods and mixes require playing with to find the optimal settings.
It is actually surprisingly easy to overheat the Cubic Mini. I accidentally clocked more than 700 degrees once during the early days. Honestly, I’m probably lucky nothing blew up, and the boat didn’t burn down!
I don’t have a magnetic wood stove thermometer, but I think it’s worth having. I’ve learned my settings using my infrared thermometer on the cooking surface. With practice, I’ve gotten where I can pretty much tell if it’s in the correct temperature zone. Wood stoves should be about 400-500 degrees for the best burn. Anything more than 600 is considered overfiring.
The temperature controls are pretty straightforward once you get the hang of them. The secondary damper has the most significant effect — opening it makes the fire burn hot, hot, hot. If it’s too hot, start by closing it all the way.
The primary damper is much the same. Opening the damper supplies more oxygen to the fire, which will get it going more and more — in other words, hotter and hotter and faster and faster. Closing the damper starves the fire of oxygen and will eventually smother the fire.
The optimum setting is somewhere in the middle, where the fire has enough oxygen for the fuel and is burning steadily and cleanly. But there’s not enough oxygen for it to roar away and eat through all the fuel quickly.
If you’re having trouble with the draft, you want the primary damper open a little more to ensure there’s plenty of air flowing into the fire and up, out of the chimney.
How Long Does a Cubic Mini Wood Stove Burn?
With the above formula, the burn time is usually one to two hours. We find we add a log or two every hour. We seldom pack it very full, so you might be able to do better than we do. We’ve found that it takes longer to light if you overload it initially. And it isn’t easy to wrangle decent-sized pieces of wood into such a tiny stove while it’s on fire.
As the fire begins to peter out, we tend to use the poker to stir it a little and then open the damper to let more and more air in. This way, it keeps the draft going as long as possible and uses as much of the fuel as possible. We are often impressed by how little ash is left in the stove.
How Many Square Feet Will a Mini Wood Stove Heat?
Our boat is a small 38-footer, and the Cubic Mini Cub is more than enough to stay warm on cold winter evenings and mornings.
Still, because of its boaty shape, everything outside the salon is cold. The stove top fan helps circulate the heat, but it is not enough to reach the far end of the boat. I think this is more a problem of the hallway and small door into the V-berth, more than the stove’s limit on how much it could heat.
After Six Years, Would We Recommend It? Cubic Mini Wood Stove Review for Boaters
So, here’s the $64,000 question (thankfully, the stove is much less than that!): Do we recommend the Cubic Mini, or any wood stove, for that matter? It depends!
Would we do it again? Probably. We enjoy the wood stove, which does what we ask it to. It’s best used on cold evenings or mornings for a few hours, making it perfect for when you’re out at anchor and it’s just a bit chilly or damp.
But using the wood stove is a whole process: finding firewood, lighting the fire, and cleaning the thing. As a full-time liveaboard, it would be nice to flip a switch and have hot air.
The wood stove is not sufficient for long-term cold-weather cruising on a boat. Boats get so cold and damp during the winter, and keeping a tiny wood stove going 24 hours a day isn’t practical. It doesn’t circulate the heat enough, you can’t use it underway, and leaving it burning while you sleep is not great.
We’ve overwintered in Chesapeake Bay and North Carolina several times and get a dock to plug in. This enables us to run our reverse-cycle air conditioner on heat and a small space heater. The reverse cycle only works if the water temperature is above 40, and even then, it isn’t very effective. But it circulates the air, and with the space heater on low, it keeps the boat comfortable.
Who Is the Cubic Mini Right For?
I think small wood stoves are more for ambiance than a full-time heating appliance. It’s great if you aren’t out in the cold often, or you have another heating system in place for those times you are.
A cold-weather cruising boat really needs to have a forced-air diesel heater, like a Webasto. If you’re considering one of these, read up on the possible dangers of the Chinese knockoffs. Even at the dock, a diesel heater is invaluable for keeping the whole space warm and cozy, and it doesn’t have the water temperature limitations of a reverse-cycle.
Pros of the Cubic Mini Wood Stove as a Heat Source
- Looks good and provides a cozy atmosphere
- Easy installation — all you need to install is the flue/chimney
- Dry heating reduces moisture in the boat, which is very helpful during damp days
- Could be used as a cooking appliance, but we find the Cub to be a bit small (if you want to cook on it, consider the Cubic Mini Grizzly)
Cons of the Cubic Mini Wood Stove
- Not really for use underway or to be left unattended
- Dirty — you must clean the ash every time, soot off the window, and clean the chimney pipes of creosote
- You have to carry fuel for it, and you have to be able to cut fuel into small pieces
- The idea, and the smoke, freaks some boaters out, which might limit your use inside a marina
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