With an ammo box, mason jar, and copper coil, I constructed an off grid water heater / heat exchanger / space heater.

Important to note:
Notice that this is an "open" system. Meaning that I made sure to leave a vent hole to prevent any pressure buildup.
This system is not for drinking or cooking, as the ammo can and other components are definitely not food grade rated. I designed this as an experimental heater only.
Once the water became hot enough, I made sure to remove the copper coil from the fire, to ensure that the temperature tolerances of the hoses and fittings would not be exceeded.
And of course this is a prototype, meaning that it's not perfect, but something I've been working to develop further.
The copper obviously isn't designed to be set directly in fire, but I simply wanted to see if the concept of heating with copper was possible. Now my goal is find a way to shield the copper from the flames in order to protect it from degradation.

Outsider Store: https://teespring.com/enGB/stores/th...

Here's a list of materials I used for the project:
Copper Coil https://amzn.to/2NJsEFZ
Tall Ammo Box https://amzn.to/2ZHn35A
Metal Braided Flexy Hose https://amzn.to/2zC1Lf4
Rain Barrel Spigot https://amzn.to/2LcdQy7
Copper Pipe Connector https://amzn.to/2Le1iq9
Candy Thermometer https://amzn.to/2MMFiEC
Digital Aquarium Thermometer https://amzn.to/2LcmAV9

Snowmobile Camper Series:
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Other equipment I use on a regular basis:
Trail Cam: https://amzn.to/2Q6MD0B
Wristwatch https://amzn.to/2ZTuTcM
Fiskars Axe https://amzn.to/2EJVdhR
Pocket Knife https://amzn.to/2Udm1MJ
Fixed Blade Knife https://amzn.to/2HnrT2i
Drone https://amzn.to/2IPucxH
GoPro https://amzn.to/2XDHRee
Camcorder https://amzn.to/2HnpLHq
Solar Power Bank: https://amzn.to/2Fgt4Og
Solar Panel (similar) https://amzn.to/2D18amh
Propane Cook Stove https://amzn.to/2CaGXgy
Little Power Bank https://amzn.to/2TeUpui
Handheld flashlight: https://amzn.to/2unfweO
Headlamp: https://amzn.to/2CyEe0u
Camping Wood Stove https://amzn.to/2UA0luc
Backup Camcorder https://amzn.to/2Tb3sMG
Flexible Tripod https://amzn.to/2EIlRrj
Cordless Drills https://amzn.to/2Tb4tV0
Chainsaw (Poulan) https://amzn.to/2IP1fls
Chainsaw (Echo) https://amzn.to/2VykyB2