Birch Tar that didn't set hard

[Hartung]

Some interesting points have been raised yesterday that I’d like to comment one by one.

Pipistrelle:

You suggest to mix “some hot pine resin” into the birch bark tar. How much is “some”. Could you give any, even approximate, percentage tar/resin? I would be grateful too if you could give us some more details concerning your experience with that mixture.

I once accidentally mixed “some pine resin to birch bark tar. I didn’t experiment with that mixture but here is a pic of it. After cooling down, the surface had lots of small crater like holes. Did your mixture had the same holes?

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[Hartung]

Jon:
You asked how to filter the pine resin. You need two pots, one metal sive with very small holes, a scoop and a spoon.

First heat some of the resin in one pot. Two to three minutes before filtering the resin put the second pot on the “fire” and the metal sive on top of it. That will heat both of them sufficiently for the filtering procedure because the sive has to be hot or the resin will occlude the sive.

Than take the scoop and slowly pour the resin in the sive. It may be that the resin passes very slowly. You can than take a spoon and push the resin through the sive. That should work quite well. The heat that comes from beneath the sive will keep it hot so that the resin will continue to pass through it.

Every now and than remove the impurities from the sive.

How to do it:

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Resulting pine resin:

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[Hartung]

Toddy:

Thanks for your nice comment. You say “It's usual to mix it [birch bark tar] with fine charcoal if it's to be used like a glue since this helps to stop it shattering.”

That is the first time that I hear someone taking about adding charcoal (powder/dust). I always heard that the birch bark tar should or could be mixed with “some” of the remaining birch bark ashes.

It is true however that the “Indians” used charcoal powder dust and added it into their pine resin-fat mixture they used to water tighten the seams of their birch bark canoes. Last year there was I time when I really did not understand how the charcoal powder would prevent the seal from shattering/breaking. So I asked someone who builds birch bark canoes for a living and he told me that the only reason why some people would add the charcoal powder is to hide “badly worked seams”. He does not add charcoal powder to the resin.

I did a small trail with adding charcoal powder to the resine and left it for more than one year but I would not say that it prevents the resin from shattering.

I also added birch bark ashes to my birch bark tar and would not say that it has a noticeably impact on the tars ability not to shatter. Its capacity not to shatter, to my opinion, is much more a question of how long you simmer it than of how much ashes you add to it.

Of course I did not add charcoal powder to my tar but birch bark ashes which are by far not as fine a dust as the charcoal. That might make a difference but I’m in doubt.

I do hope you could add more to this subject.

Left birch bark ashes, right charcoal powder dust.

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