Buy Birch pitch, one ounce by weight. This is hard at room temperature, melt with heat to apply. Comes on a fish leather wrapped stick for easy application, the fish leather is from Salmon and Cod that I veg tan in the same way that Russia leather was tanned and oiled.
When not using you should keep in a sealed container to prevent from further hardening and drying. Hardwood charcoal is added for additional strength during the refining process. Birch pitch is a finer pitch then Pine pitch and offers better performance and strength at hot and cold temperatures, does not get brittle in cold temperatures.
Larger amounts are available, please use the contact page and let me know if you would like larger amounts. Fibers can also be added on request, this enhances flexibility and strength but dries rougher.