I actually did this project last fall and forgot about it until I ran across the subject again on another site.
CAUTION: Alcohol burns pretty clean but as with all flammable liquids and heating sources take precautions with carbon monoxide poisoning other vapors and toxins that come with burning any type of fuels.
What I used and not necessarily what you have to use is the following:
1 gallon paint can
1 quart paint can
1 roll of toilet paper
1-2 bottles of Isopropyl (Rubbing) Alcohol. There are various grades or amount of alcohol in rubbing alcohol solutions running from 70% up to 90%. I haven’t found there to be a very big price difference between the grades. WalMart has a large selection and I am sure your favorite Dollar store also carries Rubbing Alcohol. I think (and I am not a chemist) that a 70% grade or solution just has more water added to it vice a 90% solution. Having said that it all burns the same in the end.
First things first, do not use old paint cans that had paint or stain stored in them previously, also do not use any cans that have a plastic bottom. The fumes from a old paint or stain will knock you out if they are subjected to heat or flame, and plastic? well it burns also.
I bought both the one quart and the one gallon paint cans new at Home Depot for around $5. You can purchase empty metal cans new from any hardware store for around the same price. I just use Home Depot because the GF works there. What I was looking for was a way to prep my cans and be able to seal them tightly until needed. I do not want to be fumbling around in the dark trying to get everything together in an emergency.
For the most part this is pretty straight forward. Remove the center cardboard tube from the toilet paper. Stuff the TP into the quart can, its ok to collapse the roll into the center where the cardboard tube was by squeezing the roll together. It will be a tight fit and you may have to remove some of the paper from the outside roll.
I tied a paint can opener (you can get free) to the handle of the gallon can.
(Sorry forgot to add the bottle of alcohol to the pic)
Stuff all the TP in the quart can after you remove the cardboard center. Or as much as you can physically get in. It should look like this after your done. Pour your rubbing alcohol into the and on top on the TP until it is soaked. It should take one bottle and a few ounces of a second. When the TP is thoroughly saturated you will know it.
At this point you can use a long neck lighter or match to light the alcohol, but this is where your gallon can comes in handy.
Before you light your quart can filled with alcohol put it inside your gallon can. A couple things here. One you can move the unit in whole without spillage, and keep your fingers from getting warm by touching the quart can. Also if you need, you can cook easier on top of the gallon can vice the quart size and lastly by putting the lid on top you can snuff out the flame without getting close to the actual fire. But to each his or her own.
For storage, seal both lids tightly with a hammer and you have two solid leak proof containers ready for the next usage.
The TP itself will not burn down unless you allow the paper to become dry. By keeping the paper wet with alcohol it acts as a wick (only replenish the alcohol when the fire is out and the can is cool to touch, don’t be stupid).
That’s pretty much it. A fairly safe way to heat a small room or boiling water for cooking.
I read an article about a family that lost power during a winter storm (northeast part of the country) a couple years ago. The author wrote that his family retreated into 2 rooms of the house, closed the doors and covered the windows with blankets. His family kept 2 cans burning for the duration until the power returned to normal. With just the 2 two cans the author claimed that he was able to keep the temperature in the mid 50’s for the rooms they occupied while the outside temps were below zero.
There are also articles how some preppers keep a can in each vehicle in the event of being stranded in a winter storm. By cracking a window, keeping a can lit the vehicle will stay warm without running the engine for the duration and possibly running out of gas. Plausible.