Things you will need:
Coffee can (I used a small one)
Couple of bolts, washers and nuts too.
Drill and bit to make hole the size of your bolts (also a step bit to make the hole for the torch.)
Scrap piece of metal for base
Plaster of Paris
Sand ( I cannot stress enough the importance of sand)
*I am going to assume that all of you on this site are competent human beings and do not need to be reminded to wear your PPE (Personal Protective Equipment) i.e. safety glasses and such. Then again we should never underestimate the power of the idiot to slip in here and do something foolish. So......... Wear the proper safety equipment and use your tools safely. PSA over.
Step 1: Attaching Coffee Can to Base
You will need a base to keep your coffee can upright while heating. Find a piece of scrap that is big enough to support the can plus 5 pounds. I recommend some channel or square tubing.
Decide where you want your holes on the coffee can and mark that distance on your base. Drill the holes to accommodate the bolts you will be using. I used 1/4" no need to go nuts here.
Once the holes are drilled, attach the can to the base with the bolt heads inside the can. I used lock washers, because I didn't want to have to worry about the bolts coming out of the base and making a hot melty mess.
Step 2: Adding the Torch Port
I used a 1/2" pipe for the torch port.
To accommodate the 1/2" pipe I used a step bit to drill through the coffee can.
Just thread the pipe in and mark where you will need to cut it off. I only left about a 1/2" inside the can and 1/4" outside.
Now the hard part is over.
Step 3: Plaster the Inner Walls.
To plaster the inner walls I used a ratio of 1/2 Plaster and 1/2 sand with just enough water to get a good mixture (about the consistency of play-doh.) Line the bottom and inner walls with about 1/2" of mixture. Try to smooth it out as much as possible. Clear the torch port of any plaster debris and you are done.
If you got the mixture right, there is no need to wait. You can insert the propane (I used MAP) into the torch port and heat away. It will take a while for the plaster to cure, but when it does it will get red hot.
Remember to use heat protection when using this thing it is small but very functional. Also the can will still get hot. I am thinking of adding some fiber insulation around it. Good luck and be safe!