Birch bark resin/tar is a dark tar like substance that is flammable and can be used as a natural bug repellent. It is a concentration of the oils found in the birch.
Step 1: Supplies
For this project you will need the following
A dead birch tree that is not super old
A popcorn tin or other tin with a lid
A mason jar
Step 2: Prepare the Tin
First you will need to poke a hole in the bottom of your tin. To do this I set my tin in the grass and used a mallet to pound a screw driver through it. The hole was about as big as my small finger. Also, try to dent the bottom so that the resin will run into the jar.
After the tin is ready you will need to collect birch bark. Always use the birch from a dead tree as to not damage or kill a living one. Peel off strips of bark and stuff them into the tin vertically. Try to fill the entire tin.
Step 3: Prepare the Fire
First you will need to dig a small hole to set the mason jar. Dig the hole just deep enough so that the opening of the jar is flush with the surface. Then set your tin full of bark on top of the jar, ensuring that the hole is over the opening. Then put the lid on the tin and begin to build a fire around it.
After the fire was adequately surrounding the tin I let it burn for close to 40 minutes before removing it. To remove I simply and carefully knocked the wood back. Then I gently got the lid off and was able to grab the can with a deer skin glove and move it off the jar. After a few minutes goes by the jar is cool enough to quickly remove from the hole.
Step 4: Uses
In the Paleolithic era birch tar was used as an adhesive for fletching arrows and lashing rawhide. It can also be used to waterproof leather. It's main use is as a natural substitute for bug repellent. Simply apply to the neck and arms and you're ready for a hike in the woods!