Wednesday 4 January 2012

thanks very much, tar

thanks very much, tar.

really its thanks very much ray mears, as it was through an episode of bushcraft in sweden that i found the answer to a problem that had been troubling me.

i had first seen the programme a long while back and was struck by the use of pine roots and stumps to make pine tar. if you wikipedia pine tar, at (www.http://en.wikipedia.org/wiki/Pine_tar) you will find a whole history about its use. from buildings to baseball, ships to sheep.

it was, as they say, the beginning of the story.

whilst i understand that some out there, who may not know me, may think i am a little eccentric, or wholly mad, and perhaps even some people who do have an idea about how i am may also think this? i would like to try and alley your concerns as best i can. i would like to think, that what i do is just that. think. think and then think some more and then when i'm done thinking, think about it some more, and then do it. however, sometimes with all the best will in the world it doesn't turn out that way. sometimes there's still not enough thinking, and there is going off not entirely cocked.

for those of you still convinced of the madness theory, who might argue its not the lack of thought but the choices, i would say that my choices are generally not driven by the ease or speed with which a thing can be accomplished. few things, in my opinion are better because they were accomplished quickly. better to do it properly.

my choices here are driven by how well i believe they are integrated in the scheme of what we are trying to accomplish overall. which, in this instance, is about how we relate to our immediate environment, and live within it, as part of it.

it means not being wasteful, but trying to utilize every conceivable part of a thing, and then trying to think up more and better uses. particularly for resources, which are never limitless and frequently require great physical effort to obtain. this i would argue is the guiding idea of permaculture or self sufficiency. make the smartest choices you can based on what you are able to obtain and the ways in which you can use them.

what we don't have is any money, and what we do have is a fair bit of experience, knowledge and tooling, and these are probably the principal and defining reasons why i do the things i do. yes, if the things were available here and we had money i would, i'm sure, like everyone else end up buying some of them. however, we are living in a third world country where there really aren't many things or access to things other than what is available, and it necessitates being inventive, resourceful, and capable. three of my favorite things, to mis-quote mary poppins.

intelligence isn't about your ability to pass aptitude tests, its about your ability to recognise the correlation between things, and to use that information in ways that help your practical understanding of it. trying to be self sufficient is all about that. how you find more and more inventive ways to use the things around you that involve less expenditure of effort and money.

in terms of resourcefulness, and use of resources, pine roots are a good case in point. following felling the tree, there is always an amount of waste, the brashings and the stump and roots. i found an answer for the brashings, the great fonds of needles on branches too small to cut for firewood, are great to burn in the bread oven, after all there is only so much pine needle tea you can drink. but what about the stumps? well you can cut them close to the ground for firewood, but that still leaves the roots, you can let them eventually rot into the ground, but the more resin they have within them the longer this takes, in the great bogs of the world they get preserved for thousands of years, and generally you would do best avoiding burning them in your stove or fireplace because they are too resinous, so what better way to use them than making pine tar, and one further thing, as a by-product of the process of making pine tar you get charcoal. two for the price of one.

several times i had been asked how i was going to treat the timber frame to prevent both insect and fungal attack? although i had planned on using diesel and have used it, it was only ever to be a temporary stop gap solution, so to speak. i wanted something that would be a more permanent answer. having the timber pressure treated was never an option, nor was the possibility of buying timber that was more durable than the stock i had. that would have been going against the whole ethos of what i am trying to do here. build a house, the old fashioned way, with the materials available. which meant using timber from our section of the forest. it was also unaffordable. the cost of sufficient timber that was more durable for the basic frame was over £5000 and pressure treatment was way over the £1000 mark. so far the pine tar treatment has cost me about £10 in turpentine and linseed oil, and i expect it to cost less than £100 in total.

so how do you prevent insect infestation and how do you deter rot? essentially they are two different questions, that can often have two different solutions. in our situation, where we have no budget, i needed to find one answer, that was cheaper than affordable, that was essentially free. and pine tar was the answer.

the question came to me a while ago, how did people treat their buildings 4 or 5 hundred years ago or more? if you take a look around south eastern england you will see that there are a lot of ancient timber frame buildings. how did they survive so long without using treated timber? or having damp courses? or even foundations? how did timbers survive placed directly on the ground? well if you look at the foundation-less buildings that are several hundred years old a number of them will have had sill repairs or replacements or be suffering from some kind of settlement or collapse because of rotting. no matter how hard oak or any other timber becomes with aging, it is difficult for it to withstand the effects of constant contact with moisture indefinately. similarly, areas where water or moisture gather, valleys on roofs, roof plates, chimney carcassing, window sills and transomes, become hotspots for decay. however, timber that has been treated with pine tar on a regular basis during its lifetime holds up better. very much better. the very existence of ancient timber frame buildings is testament to that. finland's oldest church (www.http://en.wikipedia.org/wiki/Borgund_stave_church ) , over 800 years old is a great example of this, its pine shingles on the roof are tar coated.

pine tar is a biocide, which means its a natural active preventative to rot and infestation from insects. the resin from which it is made is the thing that keeps the tree free from rotting or being eaten.

as for the process, its pretty simple.

gather a pine root mass or stump,



if its roots, ideally you want to leave them in the rain for a bit to wash off the worst of the dirt and clear out any stone before you take your chainsaw to them, or use an old chain, and then you want to cut it up into bite size pieces to allow the process of destructive distillation to remove the tar from within.



get two tins, one with a lid that fits. make a drain hole in the bottom of the lidded tin, and place that over the other tin (the catcher).



dig a hole, and place the catcher tin in it, and backfill around it. fill the lidded tin with bite size bits of resinous pine either the stumps or root mass, (the smaller you cut it up the easier it is for the tar to be released).



set a fire around the top tin and let it burn for a couple of hours.



by the end of the burn all being well you should end up with an amount of liquid tar



word of caution, you need to make sure the top tin with the resinous bits in is as air tight as possible (other than the drain hole), or the gases from the destructive distillation will ignite, and reduce the amount of tar you get. it is also advisable to keep the catcher tin out of the fire or the tar will ignite also. leaving you with nothing, but a burnt mess.

so far, i have found that if you can directly light a strip of wood from the stump with a match, then it has a reasonable amount of tar in it, and if you can't light it, don't bother cutting it up for tar making. this is a quick time and effort saving test.

to make a coating that you can use on timber i would recommend cutting the pine tar with spirit of turpentine, and linseed oil, in roughly 1/3rds, using more or less turps depending on the viscosity of the tar and the penetration into the timber you want. for the first coat you probably want more turps than tar. you be the judge. do some tests. how long will it be effective? i don't know. how soon does it need reapplying? i don't know. like creosote it depends on the situation.



i thought i was going to need a large amount of tar. after todays test with 100ml or so i've changed my mind. a little goes a long way. ta.

1 comment:

Anonymous said...

nice article and blog thanks, i read that the u.s pioneers(invaders?) used to mix linseed oil and charcoal dust -boil this mixture for 10 mins,then use as creosote.i read this in D.C Beards book shelters,shaacks and shanties.
enjoy yr project
peace and solidarity
k