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[Fourced]

I am using a 500 gal tank with a 120 gal propane tank in side it.

Does anyone have any pics of the process of putting the smaller tank inside the big one and building the door opening and the door?

Chimney, is bigger better? I am thinking 6" but I can get 8" and 10". How tall?

Do you use a grate or let the wood sit on the bottom of the burn chamber?

Forced or natural draft?

I am sure I will have more questions, thanks in advance!

Ben

[RSI]

I would go look at as many brands as you can find and try to use the best feature of each.
A 6" chimney should be good if you are going forced draft. If you do natural draft you might need larger.

I like grates with air blowing under. The fire just burns better that way.
You could just make a drop in grate and not need to do any extra welding if your inside tank is large enough. Otherwise, putting a grate out the bottom will keep the firebox full size but require a lot more welded seams. Here is an example of a drop in grate: http://www.bruteforcewoodstoves.com/stoves.html

[benj1975]

The one I Built with the 120 gal propane tank inside a 300 gal tank has a 6" chimny 55" long. But my neighbors are very far away so I wasn't worried adout the smoke. I have no grate in the bottom and it is forced air in the door. Just make sure when you put the 120 inside the your tank you leve it a inch or two off the bottom to let water between the two tanks. Good luck with the build!

[Fourced]

Is forced air better than natural draft? I have a fan that would be perfect, Maybe a bit large, but I already have it.

How far off the bottom is too far? I have it marked to be about 2.5" right now. If I made a trough under the firebox it would be like 6" off the bottom.

I haven't decided on a door design yet, I carefully cut the end cap off my 120 gal tank and I could use that as a door.

I will take pics and post them of my progress tonight.

I have lots of interesting pieces to choose from, I have been planning this for a while. I have a jail cell door that would make a nice grate, just add some expanded steel.

[benj1975]

Well as far as one being better than the other. I would say that both have pros and cons. I went with forced air gets up to temp a lot faster and can get a fire going after being idle for hours.                                           And as far the space goes at the bottom 1 or 6 would be fine just make sure you have at least 6" or more on top!

[jackel440]

I would go with forced air.
I would locate the burn chamber up about 2" from the bottom
I would use a 6" stack diameter.
I would use an insulated door on the burn chamber.DOn't waste your time with a water cooled door.just my opinion.
I would also make you door way opening as large as you possibly can.you'll thank yourself later
good luck

[Fourced]

I can use the end cap of the propane tank as a door, it would be the full 30" opening.
I can insulate it.
I can make it forced air.

That was kinda what I was thinking, thanks Jackel.

I just have to figure out how I am going to join the two tanks, mount the door, etc.

I was thinking I might add a piece of plate to the front of the tank to help strengthen it.

Is this a good choice for an aquastat?   http://www.pexsupply.com/Hydrolevel-3150-HydroStat-Universal-Temperature-Limit-Low-Water-Cutoff-for-Oil-Boilers

[Fourced]

[benj1975]

Are you going to add a baffle plate in side to force the smoke down bellow your stack?

[benj1975]

I see that you are going to draw the hot water from the top. You might want to drop that down to at lest the middle of your tank. So if your water level get a little low you won’t burn up your pump. I drew mine close to the bottom back and put my return at the top front to help it circulate a bit.

[Fourced]

I see that you are going to draw the hot water from the top. You might want to drop that down to at lest the middle of your tank. So if your water level get a little low you won’t burn up your pump. I drew mine close to the bottom back and put my return at the top front to help it circulate a bit.

I drew it a bit fast, I will be placing the outlets more near the middle and short.
The inlets will be more tward the bottom and longer.
I have not thought about the baffle, I chose to run the exhaust horizontal for three reasons, I can weld both sides at the fire box and still slide it in the tank, I will make a T at the back of the boiler with a cap so I can clean it out if needed, and to keep as much of it under water as I can.

[benj1975]

I think your ideal of keeping the stack in the water as long as posibal is a good ideal.

[Fourced]

OK, got the water jacket hole cut, and found this table.

Horizontal part of the stack test fit in the firebox.


 Set Everything in place, getting the hole placement in the back of the tank was kinda fun, but I got it right on the first try.


Had to throw in a few logs to get a feel for it.

[Fourced]

Got the bungs welded in on the back today.


Out on the bottom return to the top. Aquastat is the one in the middle on the left.

And for anyone who wonders, yes I use a 110 volt mig with flux core wire. It is a Lincoln 125 HD, and I have no issue welding 1/4".

[willieG]

with your aquastat low and near the side you might like to have a thermometer on the very top of the stove so you can see the real temp there. the astat may not give you a true reading and could be a cause for boil over on occasion? you may find you need to have the stat set lower? Maybe not, but knowing what is really going on is nice.