If you have River Birch or Black Birch, you can take some of the bark, and put it in a can, and cover it, or just leave part of the lid on, and place it on some coals, and let sit, till it starts to smoke, and then take some tongs, or sticks, and pour the tar into another can, or container, and let it cool, and then take some and heat it, to a liquid state again, and mix it with bees wax, and bunny poop, or deer, or cow poop, or some other form of a binder. Usually about fifty fifty wax to tar, as rule of thumb, and just enough fiber to help in binding the mixture. You can experiment with different ratios. You may need more wax, if the mixture is too brittle, or less if it is too soft, etc. Black Birch, by the way is what they used to use for Birch beer, and I believe also it was used make an anti bacterial, I can't remember the name at the moment. Try that and see it works for you. any of the Birches should yield tar.
Wayne