[november 2011]
Trying to make prehistoric birch tar / birch pitch...
+ more information : http://experimental-prehistory.blogspot.fr/2016/01/neanderthal-superglue-from-birch-bark.html
[[[also made a 2nd try, in year 2012]]]
First experiment : trying to find how to make birch bark tar with very primitive technology : fire, cordage, wood, wood charcoal, birch bark, soil / mud, some clay, stone.
After applying heat for some 2 hours, I apparently got some tar (very very few), but it didn't gather in the container.
[Normally, it's a process of distillation, so the gas should also have gone in the container underneath and there it should have turned into tar ... or not ???]
Things to change in the next experiment :
- less time , less heat [or more ??].
- make a bit more neatly the clay enveloppe [while viewing the vid, I discovered that there was at least a hole in the clay enveloppe].
- make a small clay funnel to ensure that the tar will flow down [should not be necessary : the distillation creates a gas that should also go underneath and turn to tar].
- more heat at the basis of the clay enveloppe (and less on top ?).
- have the strips of birch bark stand upright so that the tar can glide down along the strips [? no tar but gas where there is heat ?].
- use more bark (maybe fresher ?).
- use wild cherry tree bark instead of birch bark ?
Things that seemed OK : the 3 layered enveloppe (clay, leaves, mud).
{tags in description : burns burning poix bouleau tar pitch abedul catrame pece betulla alquitran قطران זפת 乾留液 Дёготь 焦油 Берёста Туй neandertal }