Please visit our home site at www.TRILOBOATS.com.

Anke and I live aboard WAYWARD, and wrote about it's design and construction at ABargeInTheMaking.blogspot.com.

Access to the net comes and goes, so I'll be writing in fits and spurts.Please feel free to browse the archives, leave comments where you will and write... I'll respond as I can.

Fair winds!

Dave and Anke
triloboats swirly gmail daughter com

Monday, July 8, 2024

Wood Heat for the Lazy

Spike in the Log 


Pulled from the Log


EROEI – Energy Return On Energy Invested


Wood Heat for the Lazy

It’s often said that wood is the fuel that warms us twice. But that’s understated!

Lessee…


  1. Locate, fall and limb tree (standing dead and dry).

  2. Buck into stove-length rounds.

  3. Split to various sizes..

  4. Transport to home.

  5. Stack (store) handy to stove.

  6. COOK and/or HEAT.

  7. Clean stove (periodically).

By my count, it warms us seven times! On our waterborne home, this omits fetching wood in from the woodshed. And I didn’t even mention greenwood seasonin!.

All this represents a considerable amount of energy invested in the energy returned for desired cooking and heating.

Similar to cost/benefit analysis, EROEI is the ratio of the amount of energy we get from a given energy expenditure; the bang for our energetic buck. Without doing any math, it urges us to think about our energy inputs, outputs and benefits in relation to costs. It’s an orienting concept. High EROEI is good; Low EROEI is less good. EROEI = 1 is pointless; EROEI < 1 is a downward spiral.

For fuels such as diesel, gas or electric, our personal EROEI may appear lesser, but money must be made and spent with all the energy investments that requires of us. The equation is more complex, perhaps, but pertains, nonetheless.

From our point of view, a few hours passed weekly in beautiful woods and useful exertion  in return for energy independance has been a good bargain. It has gotten us off our lazy butts and into the wider world. Our blood flowing and our backs strong. But as we age and our store of individual energy diminishes we’re looking ahead. 

What follows are a handful of approaches, resources and tactics aimed at increasing our return and reducing our investment for higher EROEI.



Smaller Volume plus Insulation

Insulation is a lesson we learned better late than never. Higher R-value hull and overheads with double-paned windows have become our standard practice. 

Now we’re looking to reduce volume. The smaller a space to heat, the less energy return is required, which in turn lowers our necessary energy investment (for heating, but also for row/sailing and maintenance).

In WAYWARD (our present boat), the living space is 20ft x 8ft x 5ft in the main, plus a trunk cabin and hatch that end up totalling about 1000ft3. The boat we’re now building for our dotage will be 12ft x 4ft x 4ft plus a small galley extension to total about 250ft3. 

We’ll have only a quarter the volume to heat!


Rocket Stoves

It’s said that the energy lost in woodsmoke is nearly half the total of unburnt wood. Rocket Stoves burn that smoke, reducing wood demand accordingly. With a quarter the volume to heat and (about) half the wood per unit of heat, we’re already talking around 1/8th the required energy investment for the desired outcome.


Furthermore, they reduce or eliminate energy invested in points 1-4 from our list above.


  1. Target small dead limbs – Thumb to wrist size covers cooking to heating. This eliminates whole tree felling and brings the dead limbs of many otherwise living trees online. In our forests, there is a super-abundance of limbs in this range, both among lower branches and windfallen. As a bonus, our coniferous limbs are sap rich near the bole for extra energy density.

  2. Process to length – All methods (see below) are much easier with small diameters than bucking sound wood. Since there is no stove box, we can use longer pieces, reducing the number of cuts.

  3. No splitting! – This is especially helpful as long-fibered spruce, generally our most practical firewood, resists splitting (which make it great for spars).

  4. Transport – Because gathering is such light duty, we can typically keep up by gathering a small amount on our daily ventures on shore, spreading effort over longer time. In our case, the heavy packs we’ve been using over treacherous footing constantly threaten strain or sprain… smaller loads are fail-safer.

These points are hard to quantify, but further increase our EROEI to a substantial degree.


Alternatives to Sawing

Sawing wood is hard work, even with a blade that is well sharpened and set (a process of considerable energy investment!). Nevertheless, it’s the least effort for bucking up rounds which are sound and of larger diameter, and/or of a tough species. For small diameters, however, other methods are faster and take less effort. As a bonus, since small stuff is less stable for sawing, the saw can skitter dangerously… other methods, while not carefree, are generally a degree fail-safer.


  • Lop – A good set of ratcheting anvil loppers (for dry wood) makes quick and easy work of any limb within its range.

  • Chop - With an ax, hatchet or hatchet/maul and a hardspot (stump or log) chop down perpendicular with a single strike on opposing sides (two, four or more according to difficulty) of a limb to create a weak spot (we’re not generally chopping through). Pull the end back to bridge between hardspot and ground and smack it with the back of the tool to break or use any of the following methods. It’s generally more efficient to first chop along the whole log, then break along in one go.

  • Break - Depending on diameter, species, soundness and dryness wood can be directly broken by hand or across a knee, tree, limb, rock, etc.. Holding to either side and striking at the breakpoint impact loads that point for usually good results (use caution to preserve your wrists against that same impact!).

  • Leverage - Leverage multiplies our power, greatly reducing energy invested. Look for a hard point and a fulcrum a little less than the desired length apart. Closely spaced trees or limbs work well, as do rock neighbors, crevasses and overhangs. Insert the stick with its end on the (further) hardspot and break point on the (nearer) fulcrum. Pry until broken. Sometimes it helps to break halfway, turn the stick 180deg and finish the other way.

  • Whack Job - This one only works with punky wood, but is fastest and very easy. Find a hardspot, preferably with a sharpish edge (rock, say). Swing the wood like a bat to impact at your desired break point. Momentum snaps the stick on contact. As with an axe, use effort to accelerate the swing but relax before impact (ride the end of the swing) to reduce shock to your joints.

  • Cudgeling - Again, pretty much for punkwood. Find a soundwood cudgel (usually about the size of a baseball bat), bridge the victim, and whop it in the middle to break. Watch out for flying ends!

All these methods can be mixed and matched as convenient. The ‘tool-less’ methods are especially helpful in the field for impromptu picnics, and help reduce long wood for a smaller, safer fire.

As you can see, the more brittle the wood, the easier it all gets. Which brings us to…



Punky Wood

Punky (rotting) wood has lost a portion of its energy content to oxidation… in effect, it is pre-burnt to a degree. But a goodly amount of energy remains. 

The benefit is that fermentation has weakened the longitudinal fibers, leaving it easy to break by any of the manual means or with ‘found’ tools. In minutes of light effort, armloads of firewood can be gathered with neither lop, chop nor saw. No tools to sharpen, transport or lose!!

While gathering, we look for the rather broad ‘Goldilocks’ point: not too firm, not too far gone. Light and dry. Well-aired in place or partially elevated above the ground, they dry quickly. The woods are rife with low-hanging dead- and fallen limbs in this state. Close to our fire, boat or dory is a plus.

Punkwood is consumed quicker than sound wood. Thicker diameters can be used to slow and cool combustion (which is proportional to engaged surface area). Where sound wood thin enough to break by hand burns away quick and hot, we can go for larger diameters in punky woods that burn cooler and last far longer. This is especially useful for even heat of a cool evening. Thick ‘uns also take up less storage volume than the equivalent mass in small stuff.

In our parts alders line much of the coast. This quick-growing ‘hardwood’ produces many dead limbs which go punky in short order. Other species such as poplars, aspens and birch are similar.

A couple of cons with this approach…

Compared to sound wood, punkwood requires more volume to transport, tend and store for any given amount of heat. Greater throughput means more ash and its clean-out. These energy investments weigh against its other gains.

While punkwood dries quickly, it absorbs water just as readily. In wet weather (which includes most of winter), it’s often too wet to use.

Still and all, for much of the year, it requires substantially less energy invested for energy returned. So low, in fact, that ‘bouquets’ of punkwood from our daily walks generally supply us with all the summertime wood we need.



‘Spikes’

Spikes are the pitchy roots of limbs from a rotten conifer trunk of pitch rich species (e.g., some pines, spruce, fir?). The pitch is energy dense AND preserves the spike AND waterproofs it… spikes are only ever surface-wet and dry quickly. The rest of the limb has usually rotted away leaving stove-length pieces.

Once the trunk of a fallen tree is fully soft, one can walk along it and harvest the limbs, pulling the spikes like carrots. Or walk along many creeks and beaches and simply pick up spikes (which don’t float) from trees long gone. A few days in the sun or behind the stove and good to go.



Bark

Beachcombed fir bark is a windfall, as fir only grows far to the south of us. Ranging from 1 1/2in to 6in thick and up to 6ft long, it is easily broken to length. Quite resinous, it resists absorbing water and dries quickly in any case. It charcoals quickly but lasts long, perfect for warming on a rainy day.

Alan and Sharie Farrell used mostly fir bark, especially in their later years. It became scarce as British Columbia logging receded, and this became quite a problem for them as time went on.

Fir bark works great in a fire-box. We haven’t yet tried it in our Rocket Stove, and I have my doubts. Too smoky? And the Rocket principle is a hot burn. 

But there are other applications…


Coppicing

Coppicing is the practice of cutting a swift-growing species (such as alders, willows, poplars and many fruit trees!) back to a stump trunk. New limbs spring up in their hundreds for sustainable harvest. It was commonly used for prolific woodlot fuel production on farms and commercial stands.

This approach looks to be a promising option for favorite spots…an arboreal guerrilla garden!


*****

There are many things we’ll miss about our current wood-range with oven. But I gotta say, its low EROEI won’t be one of them.


We’ll just have to find other ways to get our exercise!

Thursday, January 18, 2024

Wall Hangin'

 

A Wall-Flower's View


I was pretty far gone, but not so far gone that I thought anyone with half a toehold in reality would think what we were doing was a good idea.

-- Meg Rosoff


Wall Hangin'

For years we would scurry for shelter at day's end. Weather can come up from flat calm no matter the forecast, and we were afraid of the dark.

Over the years, though, we slowly got used to night sailing. Getting caught out gave us plenty of opportunities. With experience, anxieties ebbed. We learned that we could almost always see silhouettes and learned to navigate by them, the lead and echolocation. Anxiety slipped away.

We began to notice that exposed anchorings -- we call them wall hangs -- have their own attractions.

First of all, they're at hand. When the wind dies, we can most often get a hook or two down within fifty yards of shoreline. Often while it's still light and we can enjoy sunset and the last of the day.

And the view! One-eighty degrees of vistas open far and wide, unveiled by the close embrace of  cove or creek. 

The full palette of the boreal maritime rain-country waxes and wanes in intensity from distance muted greens, grays and blues to sunshot opalescences of vermilion and golds against bands of brilliant azures. Illuminated gulls like white fire against the sky, or their fuligin counterparts -- the crows and ravens -- like animated rents in the tapestry to the black, underlying void. Then dimming back to the more somber and twilit purples, perforated by stars uncounted as full dark descends.

Most nights the moon, crescent or gibbous, sails above us, illuminating cloud and fog to shades of ghostly pearl. 

And around us, the wider seaways come alive with bioluminescent script, eloquent of all that move within it; fish and kelp and wave and stone. Porpoise surging along in sprays of light, or the great whales fluking dazzlement in their wake.

We're not yet to the point that we sleep as well while wall hangin'. We doze with one ear cocked for the first ripple of wind. Best to be anchors-up and sailing before the wind comes on to blow.

But we're well compensated for these wakeful nights!


*****


A couple of observations...

  • Much of our coastline is steep-to, falling quickly off to unreachable depths. But for reasons unknown to me, there is often a ledge running along before the drop-off at around 2 to 10 fathoms. Kelp fringes tend to holdfast, along here, giving some indication of a spot to prospect at our preferred depths (about 7ftm max). Where the lead finds decent bottom, we have a contender.

  • Beware of rocks and reefs in this stretch, which are poorly charted, if at all... consider tapping around with the lead from the tender after getting a toe-hold, to confirm a clear spot.

  • Because this ledge is most often narrow, we often put out two anchors to limit swing inshore and along the ledge.

  • Consider setting a loose watch to check position occasionally... holding is unreported and likely to be marginal. We prepare to sail at the first breeze, though once awake and ready, may pause for breakfast at anchor if conditions stay light.

Wednesday, January 10, 2024

How We Got Started

M/V ANNA JACKMAN

Dave’s first ‘berth’ at 6 months



Begin as you mean to go on.

-- British Saying


How We Got Started, OR, Down to the Sea in Slips

My first sail, at fourteen, was with fellow teens in a flotilla of rafts and canoes faring from Hoonah -- in Southeast Alaska -- to Tenakee Springs and back, involving two inlets separated by a high-tide portage. 

This all went about as you might expect… passion and drama, high times and low.

One glorious, fair wind day we rafted our seven slim vessels together, erected a lattice of spruce boughs festooned with tarp and poncho, and sailed a sunny thirty miles!

Sailing!! Oh, it was wondrous, lazing along without a stroke, pushed by the kindly flow of the world! I'd had zero exposure to real-life sailing craft, and had somehow acquired the misimpression that such were nowadays yachts; toys of the very rich. Now this experience planted a seed of another species.

On to college. Strange financial terms meant that whatever I earned in summer came off my aid package. Summer overheads, in other words, translated directly to debt. What to do? Well. I hadn't seen much of the 'Lower 48'. Hitch-hiking was an obvious solution. Which I loved.

On the Road, I discovered the Tao -- that Watercourse Way – and Drift, a pace that suits me. To me the phrase, "sails full and by the wind's whim", are heart and soul of the drifting, dreaming Tao.

I considered hitching on; but the glow of the '60s was fading, and the Road was becoming dark and strange. I considered a 'hippie' bus; but a motor vehicle is no improvement on a motor boat. How to be free and footloose in a world of pistons, cogs and oil?

Musing, I returned to Sitka and signed aboard a salmon troller for a couple of seasons and worked the shoreside fish plants.

And then. And then! Rummaging through a box of Library cast-offs I came across. Sailing the Farm! A Survival Guide to Homesteading on the Ocean!! Independence on Thirty Feet!!! Ken Neumeyer, I exalt your name!

My torch was finally well and truly lit.

But to build or to buy? That was the question! Didn't help that I soon fell head-over-heels with the Pardeys and SERRAFYN/Lyle Hess! Good people; good boats - but well out of present reach.

I more-or-less wasted a few years in research, dither and scheme.


*****

Anke learned to swim before she could walk.

She grew up shoreside along the river Rhein in Duisburg, Germany; the world's largest inland port. Shipping, boats and barges were a constant backdrop. Riverside parks stretch for miles along the banks, and bridges criss-cross the river.

In Schleswig, on the Baltic coast, a family friend would sometimes take her along to join his children in working the nets.

But Europe is crowded. She was drawn to the wide wildernesses of boreal forest. She signed on for a cultural exchange, which took her to Sitka at the dawn of her adult life.

She soon found employment at Patterson Bay, a wilderness research station studying salmon hatchery. Lots of water-work, there, both fresh and salt, ashore and afloat.

And she loved cold water. There were rumors of mermaid sightings.


*****


It was love at first sight.

I was watching a small (live-aboard) sailboat for a friend who'd urged me to take it out. To my concerns that I was a pre-beginner, he tut-tutted. "If anything breaks, you'll fix her, and we'll both be the better for it."

So Anke and I headed off, on the first adventure of our new life together. All book-larnin' and no experience.

We scared ourselves, of course. Despite small, bite-sized steps we occasionally encountered a puff of wind or send of swell. Our first real ‘voyage’ had us up sailing and worrying all night, resisting the motor we had forsworn, the sooner to learn what it takes to go without.

We finally put anchor down, fell into one another's arms, and slept.

Hooked for life.


*****

In those days small, inexpensive wooden sailboats were scarce. In vain, we scoured the Seattle waterfront, looking for a small, sailing liveaboard that we could afford, yet was only moderately challenged (we wanted to learn marine carpentry, but not rebuild!). It also required that certain je n’sais pas quois.

I, of course, had my hopes set on a boat far above our means. Deep draft, ocean capable, classic! Anke pragmatically suggested that I wake from fruitess dreamboating and follow the Pardey's advice that we 'go small, go simple, go now.' Accordingly, our horizons expanded.





We found just what we were looking for in BRAMBLE (formerly TERRAPIN), a salty, gaff-rigged, lifeboat conversion from 1942. Bronze-fastened, larch-on-oak. 26ft on deck by 8ft beam by about 2½ft draft (this was our first taste of shoal draft - both serendipitous and portentous!).

The owner accepted rent-sized installments after an initial down-payment. I took a job flipping pizza, while Anke worked at a small winery. After eight months, we owned our own home, free and clear.

Our first port - while working off our debt - was in the late, great live-aboard community at Eagle Harbor, Bainbridge Island, across from Seattle. It has since succumbed to predatory Bureaucracy, but at that time was truly Magic Harbor. There, many gracious friends patiently mentored us onto the water.

Despite our (or at least my) slow and stuttering start, Anke and I now live aboard among the islands of SE Alaska's Alexander Archipelago. Since BRAMBLE, we've designed, built and sailed a series of vessels.

We sail on a shoe-string, engine-free, and are learning to subsist ever more on local forage.

Goin' on a while, now.


Friday, December 29, 2023

Buying or Selling a Vessel? Tips, Tricks and Traps

 

Illustration by Caroline Magerl of Queensland, Australia
From The Epoxy Book


Caveat Emptor (Buyer Beware)!



Buying or Selling a Vessel? Tips, Tricks and Traps


The market is a slippery, tricky place. Theory is that parties negotiate until they come to mutual agreement. Win-win. Everybody goes home happy. Another view is that it’s an adversarial contest. The seller wants the highest price, while the buyer wants the lowest. All’s fair in love and war.


One piece of advice I was given; Back off at the first whiff of adversity (pressure, hustle, prevarication, coercion). 


If we’re not dealt with in good faith, we’re likely to get cheated or stiffed. On the seller side, I’ve witnessed transactions which include hidden issues, false provenance (the seller didn’t wholly own the vessel), listed gear being stripped after sale. I’ve known buyers to skip payment/s, abscond with gear that wasn’t included in the agreement, wreck the boat and skip town.


Much better to negotiate amicably for that win-win. The waterfront is a small world, and it’s good business to make and keep friends.



Four Traps for Buyer and Seller


These traps don't themselves signal adversity. We’re all human, and these kinds of things often creep in somewhat below the conscious level.


  • Sentimental Value – Sellers often factor their sentimental feelings into a vessel’s price.  This, despite the fact that they are never-the-less unloading their Loved One on the market. No issues with their fond memories, of course, but those have zero market value.

    By the same token, our own sentimental attachments can likewise serve to jack up the price. We’re suckers for pretty, cute, trim, traditional and a host of other impressions which bias our neutral assessment. Rot, nail-sickness, blisters and other infirmities might be lurking… beauty is only skin-deep!

    They say one shouldn’t sleep aboard a vessel before buying, lest one fall in love. Not sure I’d go that far – we want to be in love – but keep a clear, cold eye on how much you’re willing to pay for it! Consider a professional survey as a reality check.


  • Sunken Costs – Closely related, seller’s often wish to make up previous expenses, which have nothing to do with the buyer. Dock and haulout fees, for example. Sellers often wish to recoup their costs, which often ends up on the buyer’s tab.


  • Issues – Just as in buying a house, issues may be dealt with before or after sale, with the price reflecting the agreement.

    Consider a well-written contract based on industry standard templates that spells it all out. Handshake agreements are well-and-good for simple cases, but a fully found vessel is complex by nature, with lots of room for mis-understanding and animosity.


  • Potential Value – Once you’ve fixed ‘er up, you’ll have doubled yer money! Um. Well. You might double the price when you come to sell, but that doesn’t automatically count the time, materials, labor and fees you’ll have supplied.

    The value of a vessel is ‘as is’, not ‘as it might become’.


  • New Prices for Old Gear – Yes, the price is high, but look at that gear list! Think of the replacement value…

    Hmm… that gear is not only used, but has been sitting around in the marine environment. It likely does have value (obsolete gear doesn’t count), but it won’t be the replacement value.


*****


Assigning value is extremely difficult. Supply-and-demand gets us started, but in the world of vessels, supply is very often low (unique or uniquely available vessels), while demand is… personal.


Cost is somewhat easier to calculate:


Consider the state of the vessel as is… take a goooood look!


Consider the time and energy required to repair and outfit to your standard.


Consider the time and energy required for long-term maintenance, including moorage.


Consider alternative options.


If your total cost from all the above plus the price you can negotiate is greater than you can afford or are willing to pay, it’s no-go.


Buyers, consider doing as much of this calculation as you can before starting negotiations… no point wasting the seller’s time and your own if it’s a non-starter.



Good luck, and win-win!



Tuesday, December 5, 2023

A DIY Rocket Stove Smoke Hood

 


Eco-Zoom Rocket Stove with DIY Smoke Hood


Somebody who claims to speak for the ‘hood don’t need no private jet.

– Chuck D



A DIY Rocket Stove Smoke Hood


About half of the energy in wood literally goes up in smoke, and with it, a good deal of our own! If the smoke can be burned, efficiency nearly doubles. The corollary is that only half as much fuel produces a given amount of heat.


Rocket Stoves were developed as a low-tech solution. At their heart is an L shaped, insulated tunnel, wide open at both ends. Fuel is fed horizontally, oxygenation and combustion burn hot at the crux, and what little smoke is left is pushed vertically, up and out the top. Typically, a pot directly atop the stove absorbs heat from the hot, gaseous outflow for cooking.


We’ve been using an EcoZoom Rocket Stove for years as a nearly smoke-free, otherwise open deck fire for outdoor cooking in hot weather, an evening blaze in nice weather and to heat metals for various projects (it easily takes ferrous metals to red-hot). It runs on limbwood from about thumb to wrist size, the former for cooking and the latter for longer, more subdued heat. In short, perfect for easy wood-gathering, especially as we age..


In planning MUSTELID, we hoped to bring this marvel indoors for cooking and heating. It requires far less wood to gather, dry and store within her small volume. Being insulated, wood can be dried directly alongside the stove, warm but nowhere near wood’s flashpoint (we can touch the stove sides without burning!).


To bring it indoors, we must gather and direct combustion gasses outboard, like any other onboard stove. The solution is a smoke hood fit snugly over the stovetop with a stack, which has the extra perk of increasing the cooking surface area. We wanted one more feature… we wanted to easily install and remove the stove for outdoor use on deck or ashore. So we went for a swing-up, cantileverd variation.


This called for some head scratching…



Grate spacer for airflow under,

Ash tray…

Whole thing slides aft behind bulkhead lip

And between heat / splatter shields.



Removed...
Note black fire-retardant pad
protecting carpet from sparks



Swing hood upward to remove


A look under the hood...
a vertical ring fits closely over upper plate
for extra fume collection


*****



Smoke Hood Plan
Not to Scale


Smoke Hood Elements


At it’s simplest, the hood is a flattish box made from sheet metal (in our case, stainless steel from and old stove’s grease trap… a heavier top plate has better thermal mass for cooking, if available. A large hole in the bottom fits closely over the Rocket Stove top, while a smaller hole in the top has stovepipe fit into it, which leads to a standard deck-jack and smokehead. If you leave the stove in pace, this is all you need.


For a swing-up top – allowing removal of the stove – we broke the hood into two boxes, each with an open end:


  1. The far box is fixed (in our case to bulkhead and flanking heatshields), with the flue let into its upper surface. Its near end is open, with rounded shoulders and an under-lip. This part is female, slightly larger than the second part.

  2. The near box is cantilevered (stops may be additionally fitted to help support heavy pots). Its far end is open, with a partial rounded shoulder fairing to 45deg… extending an over-lip, while the angled section limits upward swing. This part is male, slightly smaller than the first part. Insert its open end into the female’s until their respective hinge-pin holes align.


Other parts:


  • The long hinge pin (alternatively, short, opposing pins) are let through paired holes centered on the shoulders. If it binds while swinging upward, grind away from the lower male shoulders till clear.

  • A vertical smoke collar can be used around the stove-top cut–out (not sure it’s necessary). We used a strap of sheet metal, its edges doubled over just short of its outer mid-line (result about one inch wide) and tabbed around its outer mid-line (tabs bent alternately, slightly away from cut-out). When pressed into place, it ‘snaps’ in to lock. It works best to cut the tabs before bending.

  • Rims, rails, bars and what-have-you may be added to secure pots while cooking underway. In our case, we added a low front rim and let that and tall heat / splatter shields along each side contain pots. Watch for swing-up clearance.


Notes:


  • Any gaps allow air to be drawn into the hood. The closer the fits, the more energy is available for cooking and heating. Once the stove is drawing (seconds) there appears to be no leakage, even from wider gaps. We didn’t use gaskets, but they can’t hurt.

  • We sized our male part to be 1/16in smaller than the female’s inside dimensions. Given our crude techniques, we managed between 3/32in and 1/8in. So long as it slides in without undue forcing and the gaps are small, it should work fine. Thermal expansion binding isn’t a problem as we only ever move it out once cool.

  • In both cases, the lips should overlap the opposite part to help close the gap and contain ash. Small tabs may optionally be bent along single edges to help minimize warping with heat.

  • Sizing can be more or less according to your available space. We sized around our frypan plus our small teapot, to cook and heat water at the same time.

  • The smokehead can be lower to the deck than is usual. Although it does induce some draft, Rocket Stove’s generate expansion in their combustion chamber, and actually push gas about 40ft. Still, an efficient draft smokehead hedges our bets in some gnarly conditions.

  • We didn’t have a brake (sheet metal bender), so clamped sheets over a piece of sharp-edged hardwood, then hammered it over. Cutting was with a thin-wheel grinder and touched up with a mill file. We used bent tabs with (copper/stainless) pop-rivets to join. Wear gloves, eye, ear protection and work safe!



Looking Ahead


One of the intriguing possibilities with Rocket Stoves is to make our own from a substance that insulates, absorbs and radiates thermal energy. In other words, which acts as a thermal mass or ‘sink’. Such are easily made from brick, firebrick, concrete, clay, cob and other materials. 


Perlite (pumice) is a light, inexpensive insulator, and can be mixed with concrete for a lightweight aggregate with decent thermal mass. The combustion chamber can be lined with refractory clay. A thick, steel cook surface is easy to install over a lipped smoke chamber for a full sized stovetop / smokehood. Sand makes a good gasket between plate and stove. Alas, this doesn’t sound very portable!


But we keep on thinkin’.