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[cdie]

i think i'm finally pulling the trigger this summer on my 3 year quest for a owb.  main issue has obviously been the up front cost as i have perfectly useful oil boiler but cant afford it any more.  my last remaining question as to whether i buy or build is why cant i just heat my boiler water with a coil and store it inside my basement? my stove will be +/- 10' from my house with +/-25' crawlspace run then +/-10' in the basement. is this just an efficiency issue or something else?  the biggest drawback i see on the forums is the risk of water jacket leaking. if my thought is correct to use a large amount of coil and no jacket then it seems like a good diy project whereas the jacket may cause me to lose faith in myself. i did try to answer this myself searching existing threads and i'm sure it there but i couldn't find it. thanks for your thoughts.   

[slimjim]

 What would you use for a coil, copper would give you the best heat transfer but is expensive

[cdie]

def copper and i agree with the cost but cant believe it would come close to the $8k i need for a new boiler.  if its doable, i have propane tank available and think i would get away with $1k cost to build. (stove only)  not even trying to say i would build a product that compares in any way to a purchased unit but still attracted to the cost if it would do the job

[Scott7m]

With proper water treatment a water jacket shouldn't be concerning in a conventional design stove

[Sprinter]

I don't ever recommend building yourself. 1% of those who do succeed with a viable boiler. Copying an existing proven design is your first step to being a 1 per center. It really takes a skillful person, and unless you already have the right materials, it can get expensive fast. I would only think of doing it, if I had the materials for free. With the prices of used units or even a starter model in the ridge wood line, it's really hard to justify home built , from a cost or ROI point of view.
Besides all that, I think I would copy a garn type design. It's what most do, a barrel in a barrel, or box in box. If you can add the extra flue pipe inside the unit to extract more great.  Copper coils are great, but 3/4" soft copper is over $600 for a 100' coil. And for good heat transfer 4gpm@40degree rise is about 65' long coiled up. Rough estimate, there's a calculator for this.

Good luck, but your time is worthy too

[slimjim]

Ditto Sprinter, good post, has anybody seen my like button, seems along with my mind, I've lost it!

[fryedaddy]

I agree with Sprint & Slim, my father-in-law found a deal in an older stove with 1000gallons for $1,000.

It's not the most efficient but it's also cheap as dirt and operates as it should.

[ITO]

 Around here there are quite a few used units on Craigslist, I think with some looking around a person could do well going that route.

[mlappin]

I don't ever recommend building yourself. 1% of those who do succeed with a viable boiler. Copying an existing proven design is your first step to being a 1 per center. It really takes a skillful person, and unless you already have the right materials, it can get expensive fast. I would only think of doing it, if I had the materials for free. With the prices of used units or even a starter model in the ridge wood line, it's really hard to justify home built , from a cost or ROI point of view.
Besides all that, I think I would copy a garn type design. It's what most do, a barrel in a barrel, or box in box. If you can add the extra flue pipe inside the unit to extract more great.  Copper coils are great, but 3/4" soft copper is over $600 for a 100' coil. And for good heat transfer 4gpm@40degree rise is about 65' long coiled up. Rough estimate, there's a calculator for this.

Good luck, but your time is worthy too

man, glad you weren't around back in the day to support henry ford, we'd all be using horse and buggys yet.

I'll agree doing it yourself could and can get expensive in a hurry, but it also fulfills a need some people have to create something useful with their own two hands. To take something in their minds eye and make it tangible. Something that this country is lacking greatly these days.

[Scott7m]

 

Amen, finally

Yes it is possible to build a good working boiler yourself.   From my personal experience, most used units on Craigslist are on there for a reason

To tell someone there better off gambling on what could be a rust bomb vs building there own out of new steel, well I donno

I see both sides but a little bit of want to can go a long way

[Wood Nutt]

When I was going thru the decision process  to buy or build, I bought a set of plans for several stoves that laid out the parts of a stove.  I pulled out the handbook that told me weight of each piece and got the approximate price of mild steel and calculated what it would cost to buy all of those pieces.  It was cheaper than buying a commercial one, but when I figured I would have an estimated 80-100 hours of welding and fabrication time, I went with a new commercial one.  Getting up and burning was worth the extra cost to me.  If you have most of the parts and pieces available other than buying everything new, might make it worth the effort.

Since putting in my stove, I have come up with a 500 gallon galvanized water tank, best I can tell wall thickness is 1/4".  When my store bought Shaver rusts thru the water jacket as so many predict will happen and if they me snub me on the warranty, I may try to build my own then!   Who is going to be first in telling me to get started with the new build first!

[mlappin]

Well the thing is, when I built mine cash was extremely tight. Just married etc.

Had less than a third of the cost of new in building it myself. That was everything included, have our own mini excavator so no cost to bury the pipe either.

When I ran the numbers to finance a commercial unit it was going to cost me more in monthly payments than my gas bill was.

I already have all my controls off of ebay for less than a hundred bucks including a bellimo damper control.

The place that forms my steel uses drops off of other projects and bends my stuff as they get time, they cut me a real good price for materials and labor. May be three months before I get all the pieces but my time is limited for projects anyways.

Have stacks of barn metal around and a flashing brake, have a rather complete shop as well. Bridgeport, lathe, old cast iron pedestal drill press, plasma cutter, two wire welders, etc.

If money was no object now, I'd most rather take the cost of a new gasifier and invest in more insulation for the house, get the rest of the single panes changed out and buy a new 90+ efficiency gas furnace.

[cdie]

no offense guys but my question is not buy vs build per se.  my question is can I build a unit with a coil in the firebox to travel 10' underground and 30' in crawl and basement to an existing oil boiler that already uses circulator pumps to 2 zones of water/air heat exchangers.  I see far fewer threads and replies about 10+ years of no rust out units than the number of first and second year complete rebuilds and warranty fails.  and I am in the camp that used units are for sale for a reason so, I would rather build an outdoor stove with no jacket than risk $8-$10k on a boiler but only if the coil only works.  only material purchase would be coils (1 heat, 1 dhw) , therms, switches, and 50' underground (if I decide to run it all the way to the oil boiler).  I don't think I have enough knowhow or material  to build boiler economically.  thanks so much for your help

[mikemike]

looks like you asked a question that all these dealers dont want to give an answer to. I dont know alot but my experance with copper I would never put it into a fire box. I would use a sch 40 pipe running through the fire box insted if u want to use copper i think you would need a water jacket to keep it cool as to not over heat. but im stupid when it comes to all this so its just an opinion. the other thing i would ask is can u build one? if the answer is yes than why not

[Scott7m]

Were not replying because we either dont think it will work or we dont know if it will and wonder why there is such a fear of water, most companies who have leaks on a common basis can be named quickly