Outdoor Wood Furnace Info
All-Purpose OWF Discussions => General Outdoor Furnace Discussion => Topic started by: savebigmny on September 12, 2019, 08:39:48 AM
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Hi, I bought a house with what I think is about a 6 year old Cadillac 3600 OWB. The one corner of the opening that the door gasket closes against is corroded and thin. I am guessing the door gasket had a leak which caused this but maybe someone else has a better idea.
My question is would there be any problem with building it back up by welding and grinding to get it back close to the original shape?
My other question is maybe a dumb one but there is a blower in the filling door and also one in the ash removal door down below that appears to blow air up through the grate. Are those supposed to run at the same time or staged? Any other boilers like that? The wiring looks to have been tinkered with and I want to make sure it is set up how it was supposed to be. The company closed down that was making them so I can't find much info.
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The thin spots can be built up or just cut em out and replace with new steel.
I know nothing of your brand, is there a schematic or wiring diagram on the stove or in the manual (if you have one)?
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No manuals or schematic on anything unfortunately. I will have to take some pictures, it seems like a very heavy duty unit I saw another one at someones house about 10 miles from me, I might have to stop by and see if he has a manual.
Thanks for the comment on welding, it's a pretty small area so i will break out the Hobart and see what I can do. Not sure why it corroded away there, is that typical if the door gasket is leaking or does it mean something else?
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I'm not familiar with that model, but most others utilize a single fan either in the door, or in the back that blows up through the grates sp having both is interesting. Crown Royal uses an updraft through the grates with a "turbo draft" that's basically tubes with holes drilled in them over the top of the fire blowing down at the same time the air is coming up so it may be similar to what you have going on. Too much air isn't usually a good thing as it will push more heat out the chimney instead of into your water, but not saying 2 air sources is bad. I think the 2 fans could be very beneficial, if tinkered with and balanced for optimal burn. Is there a rheostat somewhere on the unit to adjust fan speed? A few pictures of the boiler would be awesome, if possible
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I would think both fans would need to come on together or else the top would become a chimney if it's off. I'm guessing it has a simple aquastat that cycles the fan(s) based on water temp?
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Thanks for the replies. I found out a little more information, I was browsing craigslist and happened to see an OWB that looked exactly like mine but had "Johnson" branding. I thought maybe they bought out or took over the Cadillac brand so I found their website and called. https://johnsonoutdoorwoodfurnaces.com/index.html (https://johnsonoutdoorwoodfurnaces.com/index.html) Howard the owner was very helpful and told me what actually happened is a former employee pretty much took the design and started making them on his own which is the Cadillac brand. In spite of that he was quite helpful.
He told me that yes both fans should run at the same time when the aquastat calls for heat, the second aquastat in the back should be set at 200 as a high temp cutout. Also that I am lucky mine was before the Cadillac brand ones switched to a digital controller because the one that was installed had a lot of failures and is no longer available. I believe the fans are 70cfm each. They are Dayton blowers with flaps over the inlet to block air when shut off. He also thought building the rusted spot up with weld and grinding it smooth would be the best approach. He has a fairly small operation, he said he builds about 75-80 units a year.
I will have to take some pictures.
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I got this fixed up last night, here are a few before and after pictures. And some pictures of the boiler in general. Next year summerization I will make sure it is dry inside and spray it down with some Fluid Film or oil. The welding isn't beautiful, just a Hobart 120V with flux core wire.
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More pictures, I don't quite understand how the baffle thing in the top works. There is a part that moves back and forth when I pull the handle out the front of the stove. You can see the rod in the picture of top. Also is water in the flat part that crosses the top?
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Last couple pics, and also 2 of my 3 little helpers :)
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More pictures, I don't quite understand how the baffle thing in the top works. There is a part that moves back and forth when I pull the handle out the front of the stove. You can see the rod in the picture of top. Also is water in the flat part that crosses the top?
I'm assuming it has a smoke baffle that slides open and closed. Closed sends the smoke the long way around to go out the chimney, pulling the rod let's it go straight out when loading.
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More pictures, I don't quite understand how the baffle thing in the top works. There is a part that moves back and forth when I pull the handle out the front of the stove. You can see the rod in the picture of top. Also is water in the flat part that crosses the top?
I'm assuming it has a smoke baffle that slides open and closed. Closed sends the smoke the long way around to go out the chimney, pulling the rod let's it go straight out when loading.
Ahh, thank you. That makes sense.
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I filled the unit with water on Friday night and fired it up. I saw a little water but thought it was condensation so I started the fire. After a couple hours it warmed up, I have it set to on at 180 off at 190. It seems to burn nicely with very little smoke, burning some white ash that has been dead standing I assume a few years.
I got the basement slab warming nicely, it took a couple days to get heated up.
Bad news, I noticed the water was down a little on Sunday morning and added about 12 gallons to fill it back to full. I'm pretty sure I can see a drip once in a while from the top baffle area inside the firebox. The stove is only around 6 years old as far as I can tell. But when we bought the house in June it hadn't been used for the whole previous season because the people got divorced and the lady just used the LP furnace. Well it still had a load of half burned wood in it and the chimney wasn't covered so it was pretty much festering soggy mess for over a year.
How bad is it to just keep topping the water off for now? I realize I am not going to be as efficient because I am losing 970 BTU for every pound of water leaked into the firebox evaporating. But am I going to make it worse? I need to let it go out and inspect with my scope camera to see exactly where the problem is. I hope it isn't in some unreachable area up above the baffle thing. :(
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I wouldn't see it as doing much more damage for a few days of burning- but you don't want to tackle a repair mid-winter. Access up in the top might be a challenge judging by the pictures.
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What about instead of a few days i run it through the winter just keeping it topped off?
Yes I agree access might be challenging, depending on where I might have to cut off the chimney and reach down from the top and then weld the chimney back on. No fun either way.
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Since you found a possible leak, I would check that out but running at 190 could be boiling it out. That is cutting the buffer to the boiling point kind of close. If there is any air leak, it could be boiling at random times depending on how the cycles and loads line up.
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I would agree with RSI.
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Thanks for the advice guys. I did find that my water level sight tube is dripping. I'm going to use some pipe nipples to extend it away from the heat a few inches and then use silicone tubing. It seems to be a drip every couple seconds which could add up to a significant amount of water. It was hard to see because it evaporates so quickly. I'm going to let the fire go out on Saturday and use a bottle of CF205 cleaner from altheatsupply.com and then refill and add the right amount of their A200 Corrosion inhibitor. So I will fix the leaking sight tube then and also look for any other possible problems.
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Found my leak, the sight tube was leaking so I addressed that. The clear tubing that was used was not good enough at high temperatures so it got hard and brittle. I extended the sight tube away from the water jacket by 4" with some pipe nipples. And then also used silicone tubing which should be much more heat resistant.
Then i found the real leak. On top of the baffle near the back was a rusted spot that was just dripping but once I cleaned it up with a wire brush I found one tiny hole and one about 1/4" and an area that was about 1"x6" that was rusted down pretty thin. It looks like it started at least 1/4" thick steel. It had no cover on the chimney when I bought the house so it was getting water in the top and this is right where it would puddle.
First I tried high temp JB weld that comes in a little jar that says good to 2400F. It said cures in 2-4 hours at room temperature. So I wire brushed it clean, wiped it down with brake cleaner and then smeared it on. It is more of a paste which worked well and didn't drip through the holes. I kept it warm for 4 hours until it felt hard and then refilled the boiler. At first it held but within minutes it was leaking bad. :bash:
I kept the fire going to get some heat back in the house and let it go out by next morning. Once I got in there I discovered that the stuff "unset" I don't know what to call it. It turned right back to the paste it started as and wiped right off. So I cleaned it all off and used some original JB weld which says it's good to 550F and being on the water jacket up high I doubt it will get that hot, it does not face the flames. Of course that drips through holes so i used some coated screws with a washer type head stuck through the two holes and then covered them with more. I spread a decent layer in the rusted thin area. And then kept it around 80F with a space heater for 24 hours. I'm past 24 hours now but I won't fill it and start it until this evening after work.
I'm sure others have done this. Will it hold? The only way to access for welding a new piece in would be to first cut a hole in the bottom of the baffle, or possible to take the roof apart and cut the chimney off and reach down from the top and then reweld the chimney on after. Picture shows an arrow to where the leak was.
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I feel for you, that's a tough place to get to if you need to weld. Hope the JB weld works.
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So far so good. I filled with water and started a fire last night. No leaks so far. I stuck my arm down the chimney when it was burning hard and the spot with the JB weld was only about 330 F so well within the 550 F rating. Actually all over inside the firebox the metal wasn't that hot. I think the firebox is 1/4", the water just pulls the heat away well. I turned down the temp just a little, it's on at 170 off at 180. Which my White Rodgers aquastat numbers are useless because it indicates about 30 degrees low compared to my drywell thermometer and temp gun readings.
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Still no problems. It sure uses a lot less wood now... Which makes sense. About 10 gallons of water x 8lbs is 80 lbs of water. 970 BTU/lb to flash into steam means almost 80k Btu's a day wasted.
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JB weld is holding fine. I'm loving the wood heat. My house is from 2013 and is all 2x6 walls and well insulated. I have the basement floor running on medium speed with the mixing valve as low as it goes which is about 90F. We typically need 2-3 windows cracked open to keep the house below 75. I've never needed the furnace blower to run although some radiant comes from the furnace HX anyway because it constantly circulates. Conveniently it is directly under the master bathroom so the floor is nice and toasty. And the potable water is super hot as well. The plate HX heats the well water to 155 on the way into the tank at a flow rate of about 2-3gpm, that brought the electric bill down significantly.
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I had a drain valve to decide to start leaking about mid winter last year and a drop or two adds up to a bunch of water loss. It iced over but being it was hot it still dripped.. Rigged up a plug on the puppy till this season :)