For anyone that follows my instructables, you’ll know that I have an affinity for traditional tool making and paleo/meso craft stemming from my childhood with a parent who worked for the Museums of Canada. I’ve delved, like many, into weapon making such as the bow, atlatl, flint knives, etc, but found that these items represented only a nominal percentage of what early humans were capable of. Many of the greatest advancements, made by early humans, weren’t the tools themselves, but the materials that went into tool making, and none, in my mind, is more profound than the advent of resin.
The use of resin dates back to the late palaeolithic era, and specifically birch tar is found in archaeological finds from all over the world. More than just a glue, it was used to seal boats and water containers, a water proofing material for shelters, an antibacterial for wounds, an antimicrobial for treating water, a flammable fire source, and was even known to be used as a chewing gum, the suggestion being that it was used to prevent tooth decay.
Pine Vs. Birch;
Many paleo crafters are known to use pine resin in their works, and it does function rather well, but there some serious advantages to using birch. For starters it doesn’t need to be used solely as a gum. Pine tar needs to be reduced, over a fire until it becomes a gum and is worked much like putty. Birch tar, on the other hand, can be left as a syrup, applied like a liquid glue and let to set as the natural ‘turpentine’ evaporates, albeit it can take a week or more to do so. It has a higher boiling point than pine tar does, and so arrow and spear points were less likely to come loose on extremely hot days, but most of all, it doesn’t become brittle like pine tar and retained some flexibility.
Gathering Birch Bark;
Generally, when I’m gathering birch bark, for resin making, I prefer to get my material from dead or ground fall trees. There are two reasons; 1) I don’t disturb a live tree and risk it getting infected by taking its bark, and 2) The bark tends to be much dryer and produces more resin with less turpentine.
**Note on conservation** If you intend on gathering from a live tree, the best time to collect it is in the spring or summer when there is a lot of sap in the bark, allowing it to peel off in layers. When you remove bark, you want to make sure you leave a few layers on the tree, AND NOT, peel it down to the bare wood which could cause an infection in the tree thereby killing it. If you’re collecting in the fall or winter, stick with dead fall trees, where bark removal isn’t an issue.
**Caveat** This instructable uses fire and hot materials, and though I shouldn’t have to tell anyone to be careful, I wouldn’t be doing my due diligence if I didn’t. If you’re building a fire in the city, use a fireplace with a good spark arrestor around it and wear gloves to protect your hands.***
Step 1: Tools And Supplies
- Good sharp knife
- Fireplace with Spark arrestor
- Gallon paint can with lid
- quart paint can, lid optional
- Birch Bark (enough to fill gallon paint can)
- plant fiber (will give further details later in instructable)
Step 2: Premise Of Tar Extraction And Prepping Your Materials
Premise of Birch Tar Extraction;
Basically, birch tar is extracted from bark by slowly ‘baking’ it in an airtight container, allowing its gasses to escape through the top, and letting it’s constituents drip into a lower container that is kept out of the heat. In prehistory, this was done using clay pots, but today we can do it much more effectively using metal. The end result is a thick syrupy liquid that is as flammable as gasoline (until reduction takes place) and as sticky as gum.
Prepping Your Materials;
As you can see from the photo, I didn’t use paint tins for mine, as I didn’t have any on hand, and ended up using old gallon coffee tins. I do, however recommend using the paint cans since keeping them air tight is a large concern, however if all you can find is recycled tins, they can be made to work. For mine, I simply cut the bottom out of a second tin and used it as a lid. Coffee tins come with a wide inner lip that provides a good, though not perfect, seal for air. For the smaller container, I simply used an old soup tin. I didn’t bother burning the plastic liner out of it as it would happen anyway during extraction, and wouldn’t affect the end product.
For starters, you’ll need to cut an ‘X’ in the bottom of your gallon tin and bend the points of it outward. This provides an outlet for the tar to drip into the lower container. Next you’ll want to punch a small hole in the lid, roughly 1/8″ wide. This is to vent the flammable gasses that will build up in the can. Interestingly, these gasses can actually be used to power small engines in the form of a wood gasifier, but that’s another instructable entirely. Finally, you need to fill your can with birch bark. I’d recommend layering it and rolling it up like a newspaper before inserting it as it will allow your tar to drip to the bottom more freely.