With propane going up and down and no shortage of wood I have decided to build one or more wood boiler I have a few pictures and I will post some more I used 1/4 inch plate for the firebox and 12gauge for the water jacket I am lining the sides with refractory brick and using it for the grate in the bottom. I had my steel supplier bend the fire box so there is only 1 seem in the water jacket. The fire box is 42" wide 48" tall and 40"deep the water jacket is 4" wider all the way around except on the angles on the sides about 3" there I will have 12' of chimney in the water jacket to recover as much flue gas heat as possible. By my measurements it should hold about 150 gallon of water. I did not copy any boiler on the market but I took the best parts of all the brands and made my own. I was thinking of putting 6" auger flighting in the flue pipe that runs in the water jacket to slow down and disrupt the heat hopefuly making it more efficient. I will have a clean out door on the top for the flue pipes and a forced air blower in the ash pan hooked to the aquastat and a solenoid to control the fire and water temp. Planing on spray foam on the water jacket and some barn steel around it for that nice finished look. I have had about 5 people this week see it and think they want one, Not sure I am up for a mfg business but at the cost of the name brands $5000+ there is some margin there for profit I have less than $1200 in steel and bending
Keep us posted on your progress. I can tell you that some manufacturers have had problems with cracking due to the expansion and contraction of the metal at different temps, I don't know what they did to resolve that. I've heated my home with a wood burning boiler since I built it, except the years that oil was about $1.00/gallon. The savings then didn't justify the work involved. It certainly does today!!
Great looking furnace cowman, is it going to be pressurized? My current one isn't and it's caused nothing but problems, at a little over five years of age, it rusted from the water jacket through the firebox and we had to patch it, the next one is going to be pressurized to solve this problem and having to constantly refill the water jacket manually, when its pressurized I can set up an automatic fill valve on it. What type of steel did you use, basic hot rolled, or a different grade? Keep the pictures coming it looks great so far.
I just used A36 steel for fire box and water jacket regular low carbon steel. I am not making it a pressure vessel as steam is a deadly thing and I am not a boiler maker. I think a round fire box and a round water jacket would be in order for steam. I was reading some info last night about water treatment for boilers and it makes a big difference. Randy are you using well water or do you have rual water? I think the minerels in some well water are about like battery acid around here. I also read that you need to go through a passivation process to ready a low carbon steel boiler for water.
I'm using well water and we treat the water for ph and we change the water from time to time and retreat. As for being open ventilated I've had issues, must not be the only one though, most wood boiler makers have little to any warranty on the furnaces after five years, or about what mine lasted before needing repaired or most around me for that matter after talking to the fix it shops locally. As for the process to ready it for water, I"m not sure what that would be, when I bought mine, we took it home, hooked it up, filled it and started it up, according to the manufacturers recommendations. But I do agree with you on the difference in water's mineral content, but as water is heated, cooled and circulated, air is mixed into the equation, if its pressurized you limit this somewhat, most hot water wood furnaces rust from the inside out, just what mine did, the other portion rust from not cleaning out the ashes and depending on who you talk to, can cause rust in the firebox, some claim its not possible, I wasn't smart enough in chemistry to know the difference as to who's right. I personally don't think there is much difference between a round, square or octagon firebox myself, just water circulated better around a round design I was told and the less seams to leak and cause trouble the better, also round is easier and cheaper to build I'm told, if that's true or not, I don't know. I am curious as to where you got the grates from for yours, did you get them from a manufacturer of wood stoves or out of an old wood furnace, are they cast or did you just make them out of steel yourself? I'm not sure it matters much but I'd consider putting a blower to blow into the back of the firebox somehow, to pressurize it from both ends so to speak, mine is on the front door and isn't enough, it would burn better if the air was both in the front and back and I've seen a few of the larger one's who do just that, have two blowers and as it calls for heat to have the second one kick in on the back as well as the front, with wet wood and green stuff, the more air flow the better, it'll also help with recovery and then it won't have to run as long. Again great job so far.
looks great, we have hydronic floor heat in one of the shops and can switch from electric or wood based on if we want to go outside and screw with wood or not. the shop is about 6000sq with 14' walls and is very cheap to heat. we have a pressure tank with a air venter ( cant remember what its actually called) as well as a low pressure supply valve to keep the system topped off it is suprising how much water they actually use..... beats me where the hell it goes and yes it is important to treat the water we normally test the ph and treat it every year or so. it is a system that has been operating for 10yrs now and hasnt created any problems. the wood consuption went down drastically once it finally got tuned in, the blower runs to heat the water then shuts off and the circulating pump will run till it reaches a desired low temp, then it goes through the whole cycle again. we went from a quard per week to a quard every 3 weeks, it is a large wood boiler with a box thats about 8' long and will handle any size of log that you can pick up, have thought about using a small conveyor to push the logs in and loading it with a skiddy to eliminate grunt, would be pretty cool to saw logs 6' long and press a button to load the stove but maybe this summer we'll build it but right now with neg temps its hard to think about spending too much time outside good luck with the project and keep the pics coming, i like the idea of recovering flu heat, with the thermal image camera you can see how much heat goes up the pipe and it's disturbing as hell maybe your system will cut it down pj
Hey Cowman, Looks good....not sure where your planning on getting the controls, but this place has them and the owner of this company is a helpful guy. Not sure of how his prices will compare, but this might help you out. Their catalog is worth taking a look at, has many interesting items. http://www.altheatsupply.com/blog/Make-your-own-outdoor-wood-furnace/ Outback
Hey Cowman, Nice looking stove. Make sure when you get your chemicals that they are for a non pressure boiler. The chemicals have changed in recent years. I used regular pressure boiler chemicals in my first stove and in 5 years I had a leaker even though it had a stainless tank. The manufacturer warranted it as it had a ten year warranty and I was using there chemical. In the replacement stove they sell me a non pressure chemical and "knock on wood" but after 7 years its doing fine so far.
Thanks outbackrider for the web site but I ordered everything through Grainger I checked prices and your source is about 1/2 price and the solenoid and bracket are already mounted to the blower fan, If I build any more I will purchase the kit from them. I poured the refractory in the bottom of the stove last night I need to get some pictures of it but I do have some other pictures. I have to get the 3 doors made and pour the refractory in the main door then I should be ready for insulation and outer shell. Hoping for a smoke from the chimney next week.
Door seal. Too much fire =bad. Good job. I have just never been productive enough to get one built.
Looks good. Wish I were more motivated. What's the cab over in the last pic?
The cab in the back ground is an old IH 9600 cab over getting a annual inspection and some minor repairs. I have a few pictures of the refractory brick and grates. I used 2.5"X4.5"x9" refractory brick for the grates they sit on heavy angle iron with 3/4" strap for dividers. If one or more gets broke than throw it out and drop in a new one @ a $1.85 a piece they are expendable and I think on edge they are extremely tuff. I also lined the first 22" of the slope with them, hoping to hold the heat in and keep the burn hotter when damper opens and fan kicks on. I also poured some refractory concrete between the grate and the first 45 degree angle so I would not have to miter a bunch of blocks to get them to fit the slope rite. You can see it as the discolored section between the grate and the slope bricks. I am going to try to get the doors made tomorrow. I plan on using spray foam insulation on the water tank
With the frost going out and customer machines starting to pile up the boiler project crept to a halt last week, I did manage to get a little work done yesterday afternoon. The door and latch are now mounted, I gave my hinges a lot of thought, I wanted something fully adjustable for wear and door gasket material wear. I think they are a little crude looking but they are working great and should have all the adjustment I need. The door weighs in around 150 lbs, with 1/4" plate and 2" of refractory cement poured in it.
I had a couple pictures of the door while I was pouring it, I welded 304 stainless L pieces to the door every 5" to keep the cement attached to the door then wrapped 3 layers of black tape to the L pieces, it will melt away as the door heats up and give the cement room to expand and contract without breaking or cracking. I learned a few tips from a friend who builds incinerators for hog buildings and pours this stuff in every incinerator lid. After letting it cure for 48 hours I cut the tack welds on the forms and removed them seemed to work great.
Looks great, I'm impressed with the way you did the refractory brick.
The reason the name brands are so expensive, is that they pay for ASME certifications, insurance, engineering and Hartford Steam Boiler inspections. Entering into the pressure vessel market with self engineered ad hoc designs is like putting all your money on a street corner and walking away. You can also end up in jail too.
This is not a pressure vessel. I also don't think I will sell any, just make one for the house the shop and my parents house
The earlier post mentions that this is not a pressure vessel it is vented to the atmosphere and has no way of building pressure. The water temp will be set a 185 degrees as not to be above boiling. I am open to any ideas to better this design and will except any constructive criticism that anyone has to offer but to call this a ad hoc design, that implies I haven't given this any thought and I am building it with old crap drug home from a scrap yard and that is simply not the case,
Regardless of your feelings, the design is ad hoc and it would be a poor idea to sell them. The law may consider these a boiler regardless, and even you refer to it as a boiler.
I've been kicking around building one too. I'd like to get the wood stove and the mess out if the house but like burning wood. Got a couple questions How are you going to deal with ashes? I was thinking of making it fall to the bottom and use an auger to run it out? How is the top going to work, chimney and what not. I'm a lil confused by the pictures Thanks Looks really good btw
Also what's a pressure vessel vs a vented boiler? And how could it be against the law to build one for yourself??
Joeyslushr, a pressure vessel is just that, something that builds pressure, an open vented unit by design won't, can't and never will, because its not a sealed vessel, they have a vent hole in the top, you can stick a garden hose into the water jacket, or in the event of a boil over, water will come out the top, or wherever its vented, a water heater is a pressure vessel, most commercially made fuel transfer tanks that fit in the back of pickups are not pressure vessels, they are vented, just like cowmans furnace. As for the boiler reference, all outdoor wood boilers or owb's on the market, are called boilers, that doesn't refer to being pressurized, only a few have this certification because they are truely certified boilers, all the rest are non pressurized. Some call them water furnaces, most sales people call them boilers, weather they are or not. I've been told by sales people, most people only understand water in reference to boilers, otherwise they consider them forced air units. As for doing anything illegal, cowman hasn't, anyone can build anything for themselves they want and shouldn't lose a lawsuit to anyone for it, can anyone sue him, me or anyone else for anything on earth,absolutely, but to sue someone is a long way from winning anything in court. If knocker of rock has legal paperwork documentation of anyone building one for themselves, being sued and losing in court, by all means, post it here for all of us to read. If he's designed, built and is using one himself, maybe he should post it here for us to critique as well.
Randy88 My "bromance" just got deeper. I think the only real trouble will be with code enforcement (here anyway, NY has a mountain of rules) and insurance company. OWB as they are known have had fires when they eventually get a shed over them to keep the wood dry. Last trouble will be with the folks downwind. NY got crazy with regulations because of people thinking that if it fit in the door they should burn it. First one I ever saw was a Taylor that a guy had made a re-rod cage (A'la fireplace toaster) for tires. He clamped a tire in and burned it. When reduced to wire and glass he had a handle that clipped on to the cage and he smashed it over a drum till only the steel bead was left rattling in the cage which then went to scrap. His kids all got cancer in their thirties.
Nowhere did I say that an individual could not legally build a boiler for themselves
Looking good SE-Ia Cowman :thumbsup. The only thing so far that I might question is the auger flighting inside the flue pipe . My concern would be buildup inside the flue . But as long as you can remove the auger easy for sweeping it wont be an issue . Understand wanting it to be most efficient . My dad would say " your getting to greedy " LOL . He tells me that all the time We are looking at wood stoves also with the rising cost of propane .
FarmWrench, we don't have the regulations NY does anyhow, hopefully never will, some towns and townships have banned them on their own, but no state laws as of yet dealing with outdoor wood boilers, water furnaces or whatever you want to call them. Thousands of them have been purchased in my area, maybe even tens of thousands over the last few years, along with fireplace units, basement wood burners and a host of other ways to burn and heat with wood. 100 years ago, everyone burned wood for heat in my area, it was cheap, renewable and people couldn't afford anything else, then cheaper fuel came along, and it was replaced with other means of heating, now with fuel costs on the rise, wood is back again. I realize this forum is worldwide, not just locally, every state, area and country has a different view and regulations on burning wood, some feel its bad, others great and everywhere in between, but in the end, wood is burned, if not in a furnace, outdoor boiler, fireplace, camp fire, BBQ pit, or just in our back yards all summer long in cookers, smokers or what have you, unwanted wood is grubbed off, piled up and burned in fields, along fences, in timbers or in forest fires, if it grows and dies, somewhere it'll eventually get burned somehow by someone or something, passing all the laws or imposing regulations in the end, means it'll end up being burned in another form somehow. If pollution is the problem, or smoke is the issue with some, apparently they haven't climbed into an small airplane and gone flying during the different seasons, winter has the least amount of smoke in the air as compared to summer when fire season comes along, all the wood burners everywhere can belch out smoke all winter long and its nothing compared to burning wood via other means, that nobody is utilizing. Just an observation and my two cents worth. I certainly don't want to get this thread too far off its intended purpose of cowman's furnace building project, which looks great so far. I didn't understand if he's putting the smoke through the flue pipes, or around them and water will be in the pipes? My furnace has water in the pipes and we think they are filling up with lime or something slowing down the heat transfer rate, but until I cut them apart this summer we won't know for sure.
How is ur water routed around the flue pipes, im still a lil confused at this. I realize it's to capture more heat. I'm just confused on how it's being done
Similar story here Randy88 .Cities & towns had electricity but My area (rural ) didn't get it until after WW-2 . I want to say 1949 when the power companies got all the polls set & lines run to each home . People burnt coal and wood . Pretty common for older homes to have two chimneys with a coal furnace in the basement & 3 or 4 other stations for stoves on the upper floors and a cook stove in the kitchen . The coal furnace had a heat exchanger on the back of it that ran to duct work above using convection to move the heated air upward . Big changes came after power was hooked up , people went to electric oil furnace , or electric base board heaters . Now with heating costs rising we are moving back to burning wood .
Randy, TD, Cowman, :thumbsup
Update on wood boiler I installed my boiler yesterday and got it operational, a few minor things to finish like the cover that goes on the back of the boiler to cover the induced draft fan. I also included some pictures of the tubing going to the house and my wife's kennel that we will be heating. High quality insulated pex tubing was between $11.00 and $15.00 a foot so I dug the trench, layed the pex between the house and boiler and kennel and boiler and had the guy that came to spray foam the back half of my shop insulate the pipes in the trench, I had a total of $ 3.00 a foot with insulation and pipe, and I think I have 2 times the r value of store bought pipe, It is closed cell insulation so it is a vapor/moister barrier and is 99.9 % water proof. Also included are some pictures of my 11 year old son and his friend and their lessons on hard work and a good work ethic.
More Pictures I included a few pictures of the sidearm hot water heater, the pump and the heat exchanger in my furnace plenum, I still need to insulate the 18" of pipe going up to the boiler from the trench,
When we insulated the pipe we found it was better to kind of spot weld them every 5 feet or so then he went back an really sprayed them. Also I will build a small shed around the boiler next spring but for now I painted the closed cell foam on the boiler with a good quality latex paint to shield it from the UV rays and keep the foam from breaking down and used High temp muffler paint on the doors that will get above 200 degrees
Looks great cowman, I was wondering how things were coming with the boiler. I've been kicking around the idea of building a top loader myself, so I can just dump the wood in with a skid steer, and save all the splitting completely, but that project might have to wait till I have more time on my hands. Keep us updated on how you like it, what changes if any you wished you'd have made.
Very nice work SE-Ia cowman :thumbsup We haul wood in the same way , use a couple of flat bed farm wagons with side boards .
Thanks guys, it was a large project for me as I work 40 to 50 hours a week in my shop working on other peoples equipment to make a living and this was a prototype that I designed and modified as I went, it took time and valuable shop space, the next one will go a lot faster and I will probably make 2 or 3 at the same time to save set up time and do some small production type work.