My homemade OWB

[swerner]

Hello! New to this site and have been doing a lot of reading here over the last couple of weeks.

Thought I would post some pics of my owb I built last summer. This is my second winter using it and couldn't be happier. I have noticed that everyone here likes to see pics of the other members projects so here it goes.

Hopefully I wont have any problems attaching pics as I have noticed that some have.

 

[swerner]

It seems the pics worked fine. It might not make sense until I add all of them.

 

[TFPace]

Nice

Swerner,

Nice photos.

Is your door water cooled? What do you use for gasket material?

Your design is a cylinder within a cylinder of course. What size pipe are you using for your cross-over piping? Schedule 40 or 80?

Please explain the pressure tank on top....

Are you going to use some type of baffle in the rear of the firebox to slow the flame/fire before it exits the chimney?

Will you spray insulation on the exterior or place this OWB inside a shed?

I really appreciate the pictures. I'm gathering as much data as possible.

Did you roll both tanks/cylinders or are these sections of pipe?

'Sorry for all the questions but I am excited to see this new post

Thanks and continued success!

Tom

 

[Rookie1]

Very Nice. I like to see fabbing. Nothing like saying I built it myself. Keep the pics and info coming.

 

[gwiley]

Beautiful! Next time throw in a yardstick or something for scale. That looks big enough to hide a body in

I can't wait to hear how well it performs. What did you make the auger out of?

 

[kyle1!]

When you are done building that one don't stop until you build one for me as well. Just throw the whole tree in and heat the house for a month. Curious as well on dimensions and costs to fab.

Brian

 

[swerner]

Thanks and some specs.

Here are some specs.

The two tanks are both 5’ long with one being 4’ dia and the other 5’. They are 3/8 plate that was rolled. I used this because it was new metal and I got the two for $250. The fire box sticks out a foot so there is a 1’ water jacket between the two, which also allows the chimney to be surrounded by water for that foot as well. It is 8” schedule 40 and once it passes the water jacket it t’s up into ss stove pipe.

The baffle is 2pcs 6’x10” 3/8 wall stacked on top of each other. It is located 15” from the back of the firebox. I used the tubing so water could pass through the baffle.

The door is not water cooled although I had planned on it. I got in a hurry and didn’t take the time. I started building the owb in mid September when I knew we got the house. We moved in October 1 and I had it installed at thanksgiving.

The door is 28”x32” and I used a force draft fan. The ss beer keg is a water expansion tank that I installed a sight glass on. It is vented through a exhaust flapper for a tractor. I used the ss tank so it wouldn’t rust with any condensation that would form in it.

The firebox sits 3” off of the water tanks floor. In one pic I show the pcs of flat stock getting some holes in them. This is what the firebox sits on and the holes allow the water to flow under it.

I made a frame that is welded to the front of the firebox with a .5 milled slot using a ball em. I used gasket rope to fill the groove and have a 3/8 round stock frame welded to the door. This seals it very well. Door is ¾ thick.

In some pics you can see a 6” pipe running horizontal from the firebox through the water and out through the water jacket. It is plugged off right now but I plan on fitting it with a waste oil system later. Central Boiler sells one with that option and I have a friend who has one. He purchased the waste oil system from a guy in Indiana and loves it.

It was insulated by two retired union insulators. I had nothing to do with this and I think they said it is good for 1200 deg. Then they wrapped it with al lagging and ss bands. It looks great and they did an excellent job. The cost? I had to take them out drinking the night I picked it up and invite them to the house warming party. Not bad huh?

Let me know if you have any more questions. I will post some more pics, although they are from my phone so the quality may be shady.

Oh yeah, I heat a 2500 sq’ home and 30’x40’ shop with it. Temps yesterday were 30/0 and I had 12 hour burn times. I am pleased with it. I have estimated about a 3,000 year savings in LP.

Thanks!

 

[gwiley]

Thanks for all the details - fascinating. The heat in your house is so much sweeter knowing you built the thing - my son and I did the install on the 5036, can't imagine what it would feel like if I actually built the unit.

rep coming your way

 

[swerner]

Here is few more.

 

[gwiley]

Here is few more.

Pictures in-line:

 

[TFPace]

Thank you

Swerner,

Thanks again for a very thorough explanation of your build.

I like the square tube that is serving as your baffle/heat exchanger combo.

Did you consider adding additional cross over tubes to the firebox?
It sounds like your current design is working great.

Have you calculated the water capacity of your stove? I come up with 358.5 gallons

I got the two for $250

That is the deal of the year!
By my calculations those 2 cylinders weigh 2162. lbs * $.4295/lb. = $929.45
That doesn't include the shop time to roll either.

Sounds like the 3/4" door is doing well too. I was thinking that the water cooled was must have for this big of a stove.
What are you using for a water treatment?

Thanks again,

Tom

 

[joecool85]

I'm honestly impressed. Very cool to see people building their own stuff like that. I have a small wood stove I'm working on, but nothing like that!

 

[Circle B MN]

Very impressive fab work....

 

[swerner]

Thanks to all for the kind words!! Yes it does hold about 350, I did the calculations on my cad program when I built it. The steel rings are a funny story. I have a good friend who owns a fairly large scrap yard with his father. They bought a semi load of steel plate from a semi wreck. He had the intentions of making one(owb) and had them rolled. However, he lost interest and I caught him at the right time. He sold them to me for what he had in them. Steel =free, but he paid the local metal shop to roll them.

I should also mention that I welded 2.5” flat stock at 90deg angle off of the inside of the door. This made a frame work for me to pour in refractory for the insulation. I also welded in about 9 steer horns to help hold the ref. in.

I am using water treatment from Central Boiler, they have great stoves just too cheap to buy one from them! I don’t think I’ll ever add any more cross over tubes. Reason being I can’t weld both sides. It would be hard to add some now. I would have to drain the water then cut the firebox. There would be no way to get in between the firebox and tank w/o totally removing the firebox.

I never really kept track of the cost, but I would guess the complete total with everything around 4-5K. I still had to buy a lot of steel. I also didn’t have the luxury to wait and accumulate it, I was in a hurry. This also includes pump, fan, and insulated pex line from the CB dealer. The welding wire, gas, fittings, heat exchanger all added up. A friend and I trenched (Vermeer trencher) in the line and I installed the boiler and heat exchanger which saved some $$.

Next project….wood splitter. I’m still kicking around some ideas. I have one but am thinking of making a larger one with log lift, adjustable wedge, etc…

 

[swerner]

gwiley, how did you repost my pics in line? btw, thanks!!!

Also, one of my favorite pics from the whole build.....cooler of beer and two rings of steel! Gotta love drunk talk because thats how it started!

 

[TFPace]

I got set up as a dealer for CB 8 years ago and never moved forward. I too was too tight and I had to buy 5 stoves...

I feel better knowing your friend hooked you up on the 2 cylinders. He was very kind... I'm surprised he hadn't got you to build him one.

The refractory for your door makes more since too...
You mentioned an end mill and have it pictured also, where did you use this? Wasn't it for the gasket?

Did you use couplings or weld-o-lets on the back to pipe up your supply & return lines? How many? Position? I am guessing the upper LH & RH sides?

I agree on the cross over tube?

As best as I can imagine, welding both sides of your system is near impossible except for the inner cylinder? How did you perform a leak/pressure test?

Man, I bet you had no idea that we'd cover you up with all these questions

Thanks again,

Tom

 

[joecool85]

Next project….wood splitter. I’m still kicking around some ideas. I have one but am thinking of making a larger one with log lift, adjustable wedge, etc…

Yup, you're gonna fit right in here.

 

[gwiley]

gwiley, how did you repost my pics in line? btw, thanks!!!

Also, one of my favorite pics from the whole build.....cooler of beer and two rings of steel! Gotta love drunk talk because thats how it started!

There is a row of icons at teh top of the message composition box - the one with a picture of a mountain and the sun will let you insert a link to an image in-line. Use the preview button to make sure that you have it right.

 

[joecool85]

There is a row of icons at teh top of the message composition box - the one with a picture of a mountain and the sun will let you insert a link to an image in-line. Use the preview button to make sure that you have it right.

Yeah, and you have to get the address for the images first. So upload your image, then right click on it, copy the location, go to the mountain icon, paste it in.

Simple, right?

(I'm a web professional and think it could have been built much more eloquently)

 

[swerner]

The questions don't bother me at all. I just hope this helps someone. I wish I had found this site when I was building mine.

I didn't get a pic of milling the slot for the gasket. The pic you see is when I notched the pipe for my auger system. If memory serves me correct that was a 1.5" coated roughing em in the pic. I think it is 4" dia pipe. I just programed it to cut a 2" radius in the end so it would fit up nice.

As far as the pressure testing, I just used a low pressure gauge. In the firebox I tapped a hole for a air quick connect and filled it. Then shut the valve off and made sure it held 15psi. This hole was made before I cut the opening in the door. I just tig welded in 3/4 pipe couplers for the fittings. That is were I installed the gauge for the final test. The returns went close to the bottom and pump/aqua stat both are close to the top.