At the scratchin-my-noggin stage. Hasn't been built yet. Hoping for others to weigh in.

Simple pocket rocket design build using a 20-gallon steel drum. Put SAND in the bottom of the barrel for weight.

cut a 55-gallon drum to slightly shorter than the 20-gallon pocket rocket.

Put the 20-gallon pocket rocket inside the 55-gallon drum

fill the 55-gallon drum with water

use a small pump and pump your boiling water through a radiator

reh neh. steam stove

I would mount the pocket rocket outside and simply pipe water for circulation.

I was thinking to use a toilet control valve to control water levels. But it won't handle boiling water. Any ideas on how to auto-fill the water reservoir?

any other ideas you guys might have. I'm all ears.

That will not work, you're cooling the burn too much, expect a smokey, sooty burn.

so what if instead, I build the 20-gallon pocket rocket inside a 55-gallon drum filled with sand. And then submerse the whole thing in a 400-gallon tank? Would that slow things down enough to get the results I'm looking for?

Don't realy know.

Sand is insulative, but also a heat sink. Do you necessary need to heat from the top?

Couldn't a 55 gal barrel be welded in a cutout in the bottom of your 400gal tank. And used as the barrel on a normal J tube rocket? Or even a batch rocket? That's not for bathing? Make the exhaust from the previously described barrel coul in the 400 gal tank too! Be sure do stay with a shortish pipe! like may be 20ft for a 8 incher J! You will have condensation problems. But that can be dealt with.

The reason I was wanting to feed from the top is that I was going to have a welder friend of mine build a funnel that could be loaded for auto-feeding. I live on the edge of the woods, so there is more deadfall out there than I could ever hope to burn. All looks like free heat and free hot water to me

I love the concept of an outside wood boiler, but those suckers are **expensive**. So I was hoping I might get the heat i want without emptying the bank account to do that. (hence, build my own). I was sorta borrowing the idea from a snorkel stove

Instead of a tank full of water inside the drum, how about a copper coil? A recirculating pump will transfer the water from the coil to a holding tank and from the tank to the radiator.

Bear in mind that if you want to protect the coil and tank (with a pressure relief valve and a fill valve) from internal corrosion you should use at least antifreeze as your heat transfer liquid.

Plain water once heated will have salts and minerals precipitate which in turn can corrode or plug the system.

Well, let's start from the begining.

What are your heating requirements?

Have you built a J tube rocket or a L tube rocket?