I’ve decided to make my own coad, from scratch, using local ingredients.
Step 1: forage pine resin, refine into rosin.
I spent a few hours wandering the woods where a new hiking/biking trail had been built. As I suspected, there were plenty of pruned and injured trees from the construction activity. I gathered about a fist sized amount of very dirty resin, about half of which was bark, bugs, and debris.
I melted it down in a mini-crock pot from the thrift store, one of those tiny “little dipper” crock pots. At first it bubbled a bit around the edges as the terpentine boiled off, but that quickly subsided. I ended up with a honey-like molten syrup with lots of debris floating on top.
I discovered the perfect strainer was one of those kitchen sink drain strainers. This rested perfectly on top of the melting pot. I scooped out the molten ball of resin coated bark in the strainer, with the lid on, for about an hour, and allowed the resin to slowly drip down to the pot below. This got all the bark and bugs and pine needles out, but there were still lots of tiny specks and crumbs. Hopefully those won’t be a problem.
I poured the melted and filtered rosin into a tray lined with parchment paper, and it hardened into a brittle, but slightly flexible transparent sheet.
total yield was about 40g of rosin. the debris was mixed with wood chips and chopped straw and molded into balls, placed in egg crates, to make fire-starters.