Making Colophony (Pine Resin)

There's a cemetery near my house where I regularly walk my dog, and in it there's a Norway spruce tree that produces a lot of resin. 

Over time, I've collected it, thinking that it could serve when we make casting wax. Here's a nice, clear piece:

Our recipe for casting wax is 70% beeswax, 20% paraffin, and 10% resin. In the past we've used store-bought gum arabic or damar but this time, we decided to use this cemetery pine resin. (We tried using a resinous substance from a Kentucky Coffee Tree once, but it didn't work.)

First, we needed to get the resin ready, cleaned up as much as possible, purified of bits of bark, insects, and the like. I heated it up with a double boiler, assuming it was safest to use gentle, indirect heat on it. 

It didn't take too long before it started to melt.

There were some chunks, though, that took much longer to dissolve than others, even when I put the pot directly on the heat. 

In the end, even when everything was boiling away (and I was probably burning the resin), these bits wouldn't liquify. We're not sure why that is, or what those bits might be, if not resin like everything else. But we took them out and then filtered the liquid resin through cheesecloth.

The cheesecloth was probably too fine because the liquid took too long to filter through and it ended up cooling into a chunk (now with bits of cheesecloth stuck to it, to be scraped off on another occasion). So we ended up with this:

The stuff on the left didn't get filtered through the cloth and the stuff on the right did. And here's some of that material that never melted down—looks like a nice, crispy snack, no?

To make the new casting wax, we took 29 g of this resin and added it to 200 g beeswax and 57 g paraffin. It all melted down nicely, and smelled great.

And then we cast... a pinecone! 

But it didn't quite work. The silicon mold material couldn't handle the gaps between some of the scales of the cone, so neither could the cast wax. We'll make another mold with a better pinecone pattern soon. The acorns we cast turned out all right, though.

They're a little small but I like the image of natural fruits like pinecones and acorns made of bronze. Plus, some pinecones have an interesting relationship with fire, and in fact need the heat of forest fires to open them up so their seeds can be released. Jack Pine, Pitch Pine, and Lodgepole Pine cones, for example, are tightly sealed with a resin that only melts in the heat of a fire. No fire, no new seedlings - no new life. It's a wonderful allegory to keep tucked away in a most interesting part of your mind.

a little bit of resin

not sure what kind of Pine this is but I really liked these holes where old branches used to be(?)