I grew up in Bangor.
The Unity area is awesome. Lots of hills, pastures, and trees, trees, trees.
The soil is not as boulder strewn as some parts of the state, workable soil, water everywhere. If it weren't for the snow and short summers, I'd move back.
A fertilizer spreader will probably do the job just fine. I have used the sack of lime and a cup. Dip the cup into the sack, scoop up some lime, then shake the lime gradually out of the cup onto the ground in a manner that deposits a dusting of lime on most of the ground.
Yes, those are what I refer to as big box stores.
Residential water pressure is usually between 40 and 55 PSI. To measure your flow rate, fully open a faucet, put a measured container under it (a 5 gallon bucket will do), measure the time it takes to fill the bucket. Arithmetic can help you calculate the gallons per minute your home puts out.
A simpler method to determine if you are applying enough water is to turn the sprinklers, let them run for a day, then check if the ground is moist at a depth of 1 inch. If it's dry, you need more water. If its making puddles, you can reduce the amount of watering.
If you want to measure how much water is reaching an area in your yard, put out a container to capture water. A 6 gallon bucket will do. Turn on the sprinkler, let it run for a while, then measure the volume of water in the bucket and the area the bucket covers.
Google is a search engine. Click on the link, type in 'big eye bug', then click on Google Search. You'll find numerous links about the subject. I'm suggesting that if you can find a means of encouraging a big eye bug population, they will help to control the chinch bug population via predation.
When I was a kid it was always a treat to eat something in class. For fun I'd eat the pencils!
In 4th grade we did an experiment with peas. We put seeds and soil in cups, sprouted them, every kid had a marked cup. When they were a couple inches high, some aphids that had been ordered arrived. We all got 4 aphids, let them loose on our pea. I may have eaten a couple of them. We measured and recorded the height, any changes we observed, and counted aphids. Within a few days, many of the aphids had migrated to just a few plants. As a science lesson, it was pretty safe. The plants disappeared when the experiment was over.
While this sort of experiment might be a bit much for preschoolers, the notion of starting seeds in cups would expose the kids to the growing cycle from start to finish. Started at the right time will give the garden a head start when it is time to transplant. Quick growing plants (for attention span) would be in order. Edibles will be appreciated by the kids. Peas and beans, are prolific. Root crops are a nice surprise, I'm thinking radish, turnip and carrots. Leaf crops such as mustard for a taste sensation, all kinds of lettuce greens can make an attractive garden to satisfy the administrators.
Some herbs can add another level. Rosemary and thyme can be grown from cuttings (lesson here), but are kinda slow. These plants offer aroma as well as a taste experience. Something faster would be mint, basil, and cilantro. The kids would love fennel.
Next up is flowers. Gotta have more aroma. Some are edible, but it would be your discretion to explain what is and is not edible, and not to wander the neighborhood eating the neighbors azaleas. With the flowers you can talk about bees, pollination, and where fruit comes from.
I've grown it accidentally and on purpose, but not in any significant quantity, a dozen plants to see what its about.
Annual, full sun, grows readily, needs zero attention.
takes heat, drought, and neglect, which is perfect for me.
Spacing 8" does fine for me, rich soil would be expected to produce much larger plants than what I got.
Looks like corn.
My poor production saw 1 seed in, 100 seeds produced. Rich soil should see more, as the side shoots did not produce much in the way of seed heads.
For syrup production, it is my understanding that the plant can be harvested after the seed heads mature. This allows grain production as well as syrup. The stalks need to be run through a press. Considerable pressure is needed to squeeze out the juice. Used cane mills are on Craigslist down here every now and then in the $1500-3k range. Boil the sap to remove water content as you would maple syrup. The baguesse (leftover leaves and pressed stalks) can be used for silage, mulch, fuel or compost. A couple hundred plants will produce a gallon of syrup.
I don't see being selfish conflicting with virtue. There's no rule saying you must be virtuous. Selfish is not a bad thing. You have to look out for yourself. If you can't look out for yourself, you won't be able to look out for someone else. Selfish is a fine starting point. You've taken on permaculture as an ideal and made it your own. You want to live your life by your own ideals and this is somehow selfish?
I'm totally missing the boat here.
You want to steward a piece of the world, keep it natural, help it grow, sustain yourself, plus friends and family, plus the place will have space for others who can learn and propagate these ideals, all the while contributing to saving the planet from the shortcomings of civilization and leading by example.
If that's what selfish is, I'd like to see a whole lot more people become selfish.
I've used mini blinds as well. Put em on the chop saw, cut 75 all at once. I can get 300-400 from a unit. I buy a new unit to replace an old dusty one in a window in the house. The plants don't mind the dust. A Sharpie does the job of marking. The ink will fade in a few weeks, but by then it has already served its purpose for the plant and is ready for the next use. If it has not faded, I turn it over, then upside down, giving me 4 different labellings. If I cant write on them any more, I toss em in a cup, use them when I start the same plants again.
Pencil will work on these blinds. Wet your finger, give it a rub, the old pencil is erased. My eyesight lately calls for the sharpie and BIG letters.
In the greenhouse, I used to put one of these mini blind markers in the front pot in a group on a tray. When people buy plants, they take the one with the marker. This left me with no idea what type of tomato is growing on that tray. I tell ya, they clean me right out - a couple dozen plants, there go all my markers! The solution was to mark each pot. I use disposable 16 and 20 oz plastic cups because the price is right and I can reuse them several times. A Sharpie does a fine job of marking on the cups.
Perhaps the cups would be useful to you. Use it once, give it a rinse, save on dishes. Cut it up for markers.
2) A long knife will do the job. 3"x4" is a reasonable size.
3) Just a light sprinkle. Any more will simply wash out with the next rain. You've got a microbe community in the soil. A massive dose can disrupt their balance.
4) Hard to beat compost. Purchased from the big box stores in bags, you'll be hard pressed to find certified organic. Spread a thin layer, rake it in.
5) for the 2 areas you mention, 1.5" of rain is equivalent to nearly 2000 gallons. Running at 2.5 gallons/minute, it will take 13 hours-assuming the sprinklers do their job evenly. Are you using city water?
7) Big eyed bugs are a natural predator of chinch bugs
Stinky paint is on its way out. You can still make use of it, but time is growing short. In a few months it will get funky, reek, and start to solidify.
Got any fence or exposed lumber? If all you did was freshen up a henhouse you can add life to the wood and use up the paint.
I used to pay 20 bucks for a round bale. We've had drought in this area, enough to limit supply and double the price. The midwest drought increased demand. Folks would buy rolls here for $30-40, haul them to Texas to sell for $100 or more.
Hay rolls are exactly that: hay rolled up just like a jelly roll. These can be unrolled, but after time and the start of some decay, it may not be so easy. These rolls weigh around 800 pounds dry. If they have slurped up some moisture and flattened out, you might want to skip trying to unroll the things. If you are looking for good hay in the center, this would be a simple way to get to it.
I would suggest that as soon as you have them in a desired location you cut and remove the wrap, be it plastic mesh or twine. Once decomposition gets going, it will be a struggle trying to untangle and remove it.
You have 40 of these bales, figure 32k pounds of hay. Various sources list hay the CN ratio of hay anywhere from 25:1 (I'm guessing for fresh) up to 90:1. After a year and a half, with some molding, I'd say the N in the hay is probably already consumed or dissipated. It's a pretty good bet that the hay will need at least some green material added to get it composting. On the high side, you may need as much as twice the weight in green material to get the CN ratio to an optimum level. For this sort of volume, windrows and a bucket loader can make quick work of the task. If you already have a few yards of compost available, it would do wonders if you area able to blend it with the hay and the green material you add. The purpose here is to inoculate the windrow with microbes to give it a head start. If you don't add it, the project will take a little longer is all. Compost happens.
That's if you want to play by the rules.
Left alone, the hay will slowly decompose. Mice and bugs will move in, the rolls will sag, maybe sprout some weeds, but for the most part they will stay right where they are for a while. If you can secure a source of greens in great volume to add to the hay, you can process the whole load all at once. Some machinery would make things easier on your back! If you can't process the entire load all at once, that's no problem either. Draw from the hay as needed to provide the brown material to balance what green material you have available (I'm thinking goat manure).
Using the hay as a mulch around garden plants is a fine use. As the hay decays it will add to the humus around your plants. This is a very common use for spent hay. How big is your garden? This use would not help you to produce a marketable product. It would eventually be incorporated into the soil in the growing area.
It's shoot from the hip month...
What you are describing is a humus farm operation. You want to make lots of compost and sell it. It's a noble endeavor, and the market for the product is growing.
The packaging plan can use some attention. If you are referring to plastic bags, they are not particularly strong. 40 pound plastic sacks can be had at the big box stores for a couple bucks, maybe 4-5 bucks for the premium quality Black Cow brand. If you are referring to the tougher paper lawn and leaf bags, they will probably take more weight, but I think the cost may make them impractical.
I have purchased compost in bags, but buying it by the cubic yard was cheaper. When I got a utility trailer I could handle a load much easier. Now I give a guy 50 bucks to drop off a load in a dump truck. When I bought it buy the yard, I was able to measure the volume. It took me about 50-5 gallon buckets to unload the utility trailer. The math says it should take just over 40-5 gallon buckets, but there is always some fluffing during the work. Prices for a cubic yard of compost have ranged from $18 to $33. That works out to $0.50-$.82 per bucket. Would it be practical for your customers to bring their own 5 gallon buckets? They can pack em down and pay a buck a bucket. This method has no packaging expense.
When I bought a cubic yard, the seller would load my trailer or truck with a 1 cuyd bucket loader or skid steer. 1 cuyd of compost weighs somewhere around 1000 pounds, depending on who you ask and how wet the material is. Those little trucks can only haul about 500 pounds before the start to have suspension troubles. If you don't have a bucket loader or a means of weighing a truck, the 5 gallon buckets can give you portion control. Give em 40 buckets, fill and dump.
I'm concerned about the price you paid. Around here, a fresh round bale runs me $30-40. Spent hay can be had for the taking. Loading and 15 mile delivery for a dozen spent bales would be on the order of a hundred bucks. Pretty much it's just to pay the driver and fuel. The product has little commodity value. If you keep going with this project, I think you'll be able to get feedstock for a much better price.
As Nick said: PVC becomes brittle.
My experience says it will hold up for several years, but an impact (ball/stick/fist) will readily crack the pipe in time. Mexico has more direct sun than my experience, so a couple years is probably about right.
There is the option of painting the pipe. You'll need thick coverage and darker paint would be better. This will extend the life of the pipe.
What you experiencing is called Despair. This is normal. We all encounter it from time to time.
E. Sedgwick wrote:I see only 3 options in front of me
Understandable. The first thing Despair removes is Imagination. There are so many options in front of you it would be difficult to list them.
E. Sedgwick wrote:none are appealing
Also understandable. Working for the man is no way to spend your life.
E. Sedgwick wrote:Option three, which is the best, is to live some kind of permaculture lifestyle, but the problem here is that land is really expensive and I'd still be chained to a mortgage or loan for the rest of my life. Or most of it anyway.
This conclusion is in error.
E. Sedgwick wrote:I can't just quit my job and join an eco-village because I've already accrued debt which I have to keep paying.
You have a resource: job.
E. Sedgwick wrote:I'm stuck in the system, and I don't know how to get out.
Read: I'm in the same boat as everyone else.
I have 2 options
1] Sugar coat a response that says you have your whole life in front of you and not to worry.
2] Shoot from the hip and tell it like it is.
Hey man, you are 19 years old. You have your whole life in front of you. Don't worry, things will turn out just fine.
You have accrued so much debt that you are trapped in a low wage job? What were you thinking? Did you at least get something useful for the debt or did you blow it on parties and shiny hubcaps? Chalk this one up to a growth experience and don't repeat it. When I was 22 I was paying about 200/month on interest. That was around a weeks pay each month for stuff like furniture that offered nothing in return. By the time I finished paying everything off, the stuff I bought was worn out.
One learns from one's mistakes.
About your only advantage here is found in building your credit history. Do what you can to pay down that debt. Make those minimum payments religiously. Go hungry if you have to, but make those payments on time. It would suck big time if you have to work and suffer and don't get a decent credit score out of the deal. If you succeed in securing a good credit rating, you'll be able to use it to your advantage.
Right now you have a job. You're already ahead of a whole lot of people. At least you've got some money coming in. It might be hard work, but it's a whole lot harder when there is NO work. Getting your financial house in order is tough when there's not much to work with, so go after the problem from several angles.
-Bring in more money.
Work hard and focus, if there is more money to be had in your current job, go after it. Hunt for another job that pays more, even if the job sucks. Hunt for a part time job, even if it sucks. Most jobs suck or they would not hire it out. For now, suck it up.
This is difficult because you are already scratching by. If you must, keep a record of how much you spend, where, and when. If you don't need to spend the money to survive, don't spend it. Give it ALL up: soda, snacks, movies, cable TV, cell phone, internet, clothes dryer, turn down the heat, remove the light bulbs, turn off the water heater, no drinking/smoking/drugs, no fun. Do you really need to run the fridge when there is no food in it? Pancakes are cheap. Eat lots of pancakes. If the job is so bad, it would be a shame to waste so much as a penny. Get the most from what you are spending. All too often things are thrown away that can be of use. Fix it before you toss it. When you must buy something, look to the Goodwill and 2nd hand shops first. Instead of running a TV, go to the library.
-Share the bills.
When I was in my mid-20s me and a buddy took an apartment with 4 bedrooms. We worked in a restaurant so it was easy to find roommates. We charged 100/week to rent a room, included all the utilities. Renting the 2 rooms paid the rent, lights and heat. We had it made. Perhaps this is an avenue to pursue. How many people can you squeeze into an apartment? Can you build bunks, share the bedrooms and split the rent with more people? Talk to everyone you know, chances are they are in the same boat and would benefit from a cheap place to live.
You took on some debt to buy something. Can you sell whatever it was? Is there anything else you can sell off, maybe an old stamp collection? I sold my saxaphone to pay the light bill. I don't miss it. Wasn't any good at playing the thing anyway. If the purchase is crippling you, selling it is a chance to recover at least some of the money. You don't get to enjoy the thing, and you'll take a loss, but at least you won't be as crippled.
It is all too easy to fall for the trap of consumption. You can have the world at your fingertips, enjoy comfort and style, be the envy of everyone on your block, travel to exotic places, and all you have to do is flash that credit card. Then the bill comes in. And you missed a week of work with the flu. Then the car got a flat tire. Then you got a speeding ticket. When minimum wage is all you have to work with, there is not much room for problems. There is surely no room for servicing debt. About all you can do is rent a cheap basement apartment, run a light bulb, and eat mac n cheese. I ate a lot of mac n cheese back in the day. You've made your bed, now you have to sleep in it. It won't be easy or quick, but people dig themselves out of holes all the time.
The challenge is to start over, while still encumbered by the mistakes you have made. It takes sacrifice, commitment and hard work to take care of the basics of food, shelter, transportation and debt. Once you have those, Creativity can go a long way towards getting ahead. Understand that the rules of the system are not written in stone.
You don't have to own the land. You only need the use of the land. You don't have to pay for the land either, you may be able to use land by offering something in exchange. If you can produce something from the land, say, vegetables, you would have something to trade. Put ads online, in Craigslist, ask around, talk to everyone you know. There is land out there that is not being used, and could well be owned by someone you already know. "Let me use the land to grow vegetables, you get all you can eat, I can sell the rest." This plan offers income, cuts your bills with food on the table, gives you a chance at real world hands on experience, makes the landowner happy, and puts you in front of paying customers.
Time for some arithmetic
50 weeks/year (2 weeks off for the flu and visiting grandma)
this does not include taxes
A part time job pulling in half that, $7000/yr, would go a long way towards wiping out that debt.
Even if you paid 30% in taxes on that, about $5000 for the year would be a big shot in the arm
Say you grew vegetables on this borrowed land to sell, either at a farmer's market or Pick Your Own.
A price of $1.50/pound is a fine deal by supermarket prices.
If you were able to raise and sell 5000 pounds of vegetables, 5000 x $1.50 = $7500. This is equivalent to a part time job.
At the very least you will need some seed ($50-$100) and a shovel ($20 or borrow one).
For a polyculture of 20 different plants, 250 pounds of each type of vegetable. That's doable.
Tomato, green pepper, cabbage, turnip, beets, cauliflower, brocolli, spinach, peas, lettuce, cucumber, carrots, zuke, butternut squash, pumpkins, corn, eggplant, romaine, onions, celery. That's doable
Done in growing beds 4' wide, 50' long, 200 sqft/bed. You can fit plenty of stuff in there. 1800 onions, 50 tomato, 200 cabbage, 400 lettuce...if you were able to raise 200 pounds in 200 sqft and threw away HALF, all you would need is 50 beds. Even with 4' paths between the beds, all you need is a half an acre of land.
There is information all over these forums on how to raise vegetables naturally, with little or no water, with free inputs, compost, mulch, and pesticide free. If you can't find the information, all you have to do is ask.
During the cool season, make compost. Do it again next year. Pay off that debt. Save your pennies.
Build that reputation.
Do it well, give the people what they want, you can take on more land, even if you have to rent it and pay for pumping water.
How far you can go is up to you. You can follow the path of the CSA, get paid upfront, buy land, move in, set up renewable energy, orchards, chickens, dairy cows...
Concrete driveway technology is fairly simple: roughly level the area, fill big gaps with riprap, add a compaction layer of lime/sand/gravel/and or rocks, optionally add rebar or wire mesh, form with lumber, pour.
You say you have a gravel base, so it was probably a decent installation rather than a weekend warrior slap it together cob job. Chances are you will encounter wire mesh. Simply breaking up the concrete will be difficult. A concrete saw will give you a leg up on the demolition. They are heavy and slow, but will make easy work out of the concrete and the wire mesh.
If there is wire mesh, the cut blocks may not be desirable for repurposing. The metal ends will be razor sharp. If there is no wire mesh, or if you grind the ends down, the cut concrete can become a resource saving you the cost of disposal.
The ground under the concrete will be a challenge. If it was not packed down before the concrete was poured, the weight of the concrete over the years will have packed down the ground. If riprap was added as a filler, you can expect rocks, broken bricks, scrap metal, masonry, and god knows what else. All you can do is scratch and dig. What you will end up with is anthropomorphic soil. Hard to say what is going to grow in it, but with some effort as you described, it can be remediated.
Down here, a concrete driveway is considered a property improvement and is subsequently taxed. You may want to check with the property appraiser to have your property tax adjusted once the concrete is removed.
Being a year old, it will have decomposed to some degree and lost some of the N, depending on how deep the heap is and the amount of air circulation. With a month left before planting, there is still time to amend the soil with this material. If it heats up, it will be a result of the microbes consuming the N and you may yet damage tender seedlings. If it does not heat up, it is not likely to burn or injure the plants, pile it on.
In my experience, at a year old this stuff is probably ready for use in any quantity you like.
If I had free access to unlimited organic dairy manure I'd take full advantage of the opportunity!
At times my job brings with it some punishing physical labor. Parts that you never knew you had will be stiff and sore. Each time I climb a set of stairs I swear they added more steps to it. Lifting, heaving, throwing, pushing, bending, climbing, crawling, cursing and praying. The older I get, the more it hurts, the longer it takes, and the less I enjoy it. It's tough enough getting out of a warm cozy bed on a cold morning knowing I'll spend the day moving a few thousand bricks. It's even tougher the next day when I can barely move.
Don't Overdo it.
Your body will let you know when it's had enough. Listen to your body.
If you need a rest, take a break. You've only got so much energy available in your bloodstream. Use it up, your body needs time to draw from its reserves in order to keep you going. A piece of candy or a cup of coffee will help keep up your energy, but it does nothing about the impact and strain which is what will make you sore and stiff. If your lifestyle has been more sedentary, you will do yourself a favor by gradually moving into the heavy labor- an hour here and there today, tomorrow a couple hours in the morning plus a couple more later on, the next day give it some more. Your body has limits, but you can expand those limits in just a few days.
Get the muscles moving, get the blood circulating. Starting the day like a sprinter is asking for aches and pains. The human body is able to perform for long periods under difficult conditions. What you can do and what you think you can do are often unrelated. Give your body a stretch, go for a walk, rake up a wheelbarrel load of leaves. These are not strenuous activities and can be enough to help your body move fluids around and get its housekeeping in order. You'll be able to do more than you think.
I see new guys come to work with a pouch of ramen noodles or a McYummy and expect to get through a 12 hour shift. They can do it for a day, but it does not take long to learn that long term performance is directly proportional to diet. I give them a mnemonic: Bread and Meat, Salt and Sweet. Bread and grains are quickly digested and offer energy. Meat brings protein to keep up muscles and bulk calories to carry your energy for the day. Salt keeps your fluids in balance. Sweet, more than anything dietary, keeps up your attitude. Your entire body is involved in the work and not all parts of your body have the same needs. A diverse diet feeds your diverse parts and allows your body to take care of itself.
If you are not sweating or peeing, you are not drinking enough water. Everything you eat is water soluble. Every muscle, nerve, organ, tissue, and bone, is bathed in fluids. If you drink too much, your body will get rid of it. If you don't drink enough, your body won't function as well. You'll stiffen up, undernourished muscles will ache because they are not being flushed properly. Way too little, you'll cramp. A little gatorade can be a treat, but if you are drinking more than a couple of them in a day you are asking for trouble. A little coffee, sure. Coffee all day, not so good. You dont sweat soda, milk, tea or energy drinks. Your body needs water. Drink water. If your diet is diverse, you probably have the nutrients you need. All that is required is water for delivery.
Rest and Breaks
After a couple hours of steady humping, take a break, drink some water. 15 minutes for a snack, half an hour for lunch, longer if you are old and busted like me. When it's time to get back to it, get your blood moving again-walk around the house, go check the mail.
The right tool for the job can mean the difference between work and torture. Personal experience is limited. Use the forums to ask about different tools. You can access the experience of thousands of people.
Everyone has their own level of acceptance regarding contaminants. Is a tiny amount of preservatives in a few loaves of commercially produced stale bread going to make you lose sleep worrying about your compost heap? Do you support the ideal of organics to the extent that Zero Tolerance is what you live by?
Are there ways to process the grocery store material in a manner that mitigates the contaminants? Feed the stuff to chickens, use the chicken manure to raise worms, use the worm castings to raise flowers to attract bees to pollinate your organic crops.
It is up to you to determine what you will accept.
What would I do?
Would I consider the action a violation of my ethics?
Would I proceed to violate my ethics?
Are my ethics for sale?
With this is mind, what would you do?
Setting aside personal ethical issues for a moment, you have the opportunity to observe how easy it is to place faith in technology. You also have the opportunity to gain an objective viewpoint on why the owner of the operation made the switch from organic to chemical agriculture. In order to avoid temptation, it can help to know what sort of temptation is out there.
To get the material to move tightly into corners, use a poorman's vibrator.
Place a small board on top of the mold. Apply a random orbit sander to the board. The vibration of the sander will work with a thin casting.
The mold can be covered with plastic or a towel for easy cleanup.
Refractory is not concrete. You'll want to cure the cast in the manner for which it is designed.
Refractory moves the heat through the mass. Concrete is a poor conductor, heating unevenly.
Let it dry for a while before you burn, 24-48 hours is a good rule of thumb for this size. Longer won't hurt a thing. If not fully dried, several burn cycles would promote cracking rather than prevent it. If you want a more gradual cure, start a small fire, increase its intensity gradually, but get it roaring and keep it going for several hours, cooking the entire casting in one continuous burn. All of the moisture wants to be driven out before it cools or you will have an incomplete cure which will invite thermal fracturing. Burn it all day.
If you do get cracks, don't be alarmed. Some cracking will be expected. During the first burn, these will allow the exit of steam out of the casting. When the casting is heated, it will expand, shoving those cracks back together.
I'm thinking this out a bit more.
Sonotubes can be used as a form. They can be left in and will burn out without causing injury to the casting. The casting will handle those high temps as well as the abuse of flame contact. The burning of the sototube will actually help the casting cure before it is burned out and the flames reach the casting surface.
If you want to go to the extra effort, you can mix a small batch of portland into a slurry. Just before you pack the form, use a paint brush to apply a thin coat of this slurry to the burn chamber form, a little at a time just before you pack that spot. If using sonotubes, apply this slurry to the outside of the sonotubes. Here's what happens...as you pack in the castable material, the portland slurry is still moist. It will hold onto the refractory but won't be stirred in. The added moisture will be insignificant. Any flaws in the form material will be smoothed out, giving you a smoother casting. When you fire the unit, the portland won't survive the heat, but will serve as a sacrificial coating, protecting the castable for that first firing. The thin portland will simply flake off within the first couple of burns. You will have some fine cracks no matter what you do, but this thin slurry will minimize them. With a smoother casting on the surface of the burn chamber, you will gain durability, particular at the corners and higher abrasion points.
Exposed surfaces can be smoothed with a moist brush, moist sponge or trowel. Same idea as the slurry above, except without the portland. This is more for aesthetics than anything else. Makes the surface a bit less rough
Expansion Joints are probably not needed for this small size. Where you do opt to use expansion joint, packing them with mineral wool or fiberglass will help to cushion the squeeze as the 2 expanding sides come together. If covering the core with cob, you would be well advised to cover the core with a thin layer of mineral wool or fiberglass. You won't need much-you're not trying to insulate the space between the core and the cob, you just want enough to be compressed as the core expands so as not to crack the cob.
Hi Thomas. That's my video you linked to.
I just now caught this. Well done! I've seen Pros do sloppier jobs.
I just watched the video:
The fiberglass he shredded up-that's the crystalized silica I mentioned. If the material is already in the dry mix, it will be small particles rather than clumps. His recipe will improve the finer he shreds it.
Water-use as little as possible to get the material to hold together. In my experience, the mix in the video is on the wet side. Minimal water translates to minimal cure time.
Method-I see nothing wrong with what he has done in this video. Form build, mix, cast, burn...all looks good to me. I project he will get excellent service time from this casting. I would add 2 tips:  Mix well-you want as uniform a blend as possible.  Pack the material in TIGHT. In the places where you can only access with your hands, press the material in just as hard as you can. In the areas where you access with a tool, pound it in with a 2x4 or hammer. Leave no air pockets to weaken the casting.
-When mixing dry refractory castables: WEAR A PARTICULATE RESPIRATOR OR N95 PARTICULATE MASK.
The crystalized silica is highly abrasive to lung tissue and a known carcinogen. You don't want to breath this stuff all day.
-In the video, take note of the gloves. You will be pressing HARD on the material to get it into the corners and pack it solid. The stuff is abrasive to your hands. Rubberized gloves will protect your soft, delicate hands. As an added bonus it lets go of the material as you work with it and cleans up well with just water alone.
I'm a foreman and sometimes field supervisor for an industrial refractory contractor. I'm not a mason, but I work closely with them (as in 'no room for car keys').
The industrial refractory industry has been changing over the past 20 years. Where firebrick was once the dominant material, castables and monolithic slabs have been gaining in use and effectiveness. Castables in particular have been developed which offer as much or more durability as firebrick, but with an installation time of a few days rather than a few weeks. Rather than a crew of masons laying brick at a rate of 500/shift, plus labor to get the bricks and material in place, the procedure is handled with a couple of carpenters and a pump.
The recipe above looks like it will work just fine in the environment described. AP Green or Harbison Walker puts out a product called Online 70. It's primarily applied as a shotcrete. We've used it as a castable repeatedly in kiln and boiler repairs. Another product is KS4 which is primarily applied as a castable material. These will both perform far beyond residential demands. Once the material is applied, we'll put some heat to it for 24 hours-a bigarse propane burner blasting all day and night to cure the job, at which point the vessel is turned over to the plant ready for use.
Refractory mortar differs from portland cement because of the addition of alumina and or crystalized silica. These allow the heat to penetrate rapidly through the material such that it heats uniformly. This prevents one side being substantially different in temperature which would result in thermal fracturing. The mortar would disintegrate rapidly with each heating and cooling cycle. Castable refractory material has these same heat transfer properties.
I have a Magic Chef which operates on 1.4 amps for cooling, 1.76 amps for the defrost cycle. I think its 10 cuft. Plenty of space for me.
Sunfrost is a brand that produces highly efficient appliances. I don't know much about them but I believe they offer DC models.