View Full Version : Pine tar, in case you did not know.
01-14-2003, 03:19 PM
I found my pot of pine tar I bought 10 years ago or more. Here is what is says."Smoke from Goldex Pine tar aids in the treatment of distemper in horses". (What about us?) "Pine tar is also effective as foot packing for horses. Prevents slipping when used in threshing machine belts, etc. Use for cuts on sheep when shearing, or cuts from wire, etc, on any animal". This just in case you did not know what else to use it for if you don't mix it with linseed oil and terp.
01-14-2003, 04:01 PM
Somebody here once was a having a hard time finding "real" pine tar. The solution? A veterinarian's supply house! ;)
01-16-2003, 09:04 AM
Tar is a sort of a fresh product. I use about a gallon every year for regular maintenance of three small boats and occasional projects. If it's stored in a plastic container, the lightest fractions go straight through the plastic and your tar can looks like a raisin in the springtime.
The difference on fresh and olf tar really can be seen on light wood: fresh tar brings an light amber colour after a few applications and several years old tar would make the surface very dark with the same finish.
Old tar has to be thinned down a bit with pine turpentine and linseed oil to get it soak to the wood as fresh tar. And tar is always applied hot, regardless of wether you have thinned it or not.
Tar can be used old, but it's not the same. My boat was tarred for years with tar that was dug out of 10 year old tarpit. The tar was full of sand and consistency wos closer to pitch but it protected the surface anyway. Ugly it was, but the wood was safe.
Quarts of tar... At the shipyard where my boat is they buy it in barrels for the old ships. You can just imagine the scent around there.
01-16-2003, 10:24 AM
Whew... I thought you were going to tell me it was carcinogenic or something. The hardware store attendant was speculating on why they could not sell as a paint additive only as a horse remedy. Anyway, if someone knows, please keep to self. I prefer ignorant bliss.
01-16-2003, 11:58 AM
Hey Pekka! Im curious and I guess offering up "dingos dumb question 1001 b"... why is the tar applied hot? couldnt it be applied cold? what is hot? boiling hot? to hot to touch? warm to touch? dont touch? just hot? how is best to apply?
Mind here in me younger days as a rouseabout in the shearing teems I used "tar" on the areas of the sheep that the sheerer decided needed painting which was often near on the whole sheep if a learner was sheering and we just had a tin of black tar and whacked it on the cut with a paint brush and that was cold sticky goop same stuff from the discription that was quoted above... but pine tar? Im not so sure now will have to go have a yarn with an old sheering mate and work it out maybe we just used emulsion from road works? :eek:
Take it easy
01-16-2003, 12:18 PM
Speaking of threshing machine belts... smile.gif
I remember my old pappy using tar on the belts in two forms. One liquid which he dribbled on the belt and a solid stick form which he held aginst the belt as it ran.
The feeder to the threshing machine was 25' so the drive belt between tractor and machine must have been some over 50', unshelded of course. There must have been a couple dozen other belts on the machine of one size and another.
01-16-2003, 10:49 PM
I just pulled Wooden Boat No. 142, 1998. There one finds a long article about the demise of the longleaf yellow pine in Virginia and Taxas. It also talks in detail about pine tar, "technically called turpentine", and the way it is harvested by wounding the tree, (like harvesting Maple syrup) and then distilled. The stickey stuff left over is the pine tar we are talking about I think. I wonder whether the turpentine we buy under that name is real turpentine, i.e. from the pine tree. The same article suggests that the real pine tar has now been replaced by "Stockholm tar". Maybe our friend from Finland can clarify some of this. You may have plenty of Pine trees there. I am not aware of pine trees being "sapped" in Canada.
01-16-2003, 11:01 PM
I don't know about using pine tar on the sheep, and I know for sure the horses would give me a great walloping horsebite if I ever tried to get near with that stuff. (for that matter, so would SWMBO, near to the horses that is.) Up here we tend to use iodine when shearing or foot trimming. Maybe this is because when we shear in March it can still be way below zero, so road tar is a little hard to come by. The little beggers shiver so, it's a pitiful sight.
01-17-2003, 07:25 AM
It may not be a cancer agent, but it can cause homerun disqualifications and run-ins with the late Billy Martin....so use with care.
01-17-2003, 07:47 AM
I have to get my hands on that old Woodenboat issue if they say that tar is made as maple syrup. Boy you have some odd habits around there... And at least local pine pitch can hardly be described "sap", it's as close to sap as cask strength whiskey is to light chardonnay.
Tar and turpentine both come from the pine tree, but in these days they come from totally different process. Turpentine comes out as a by-product for paper industry and tar is burned in a tar pit. In the old times it was a different story. The first fraction coming out of the tar pit is called "tar piss". It contains pretty much water and is useless. Next fractions are called "black tar piss" and it's generally turpentine, it's just darker as the industrial product today. After that you get tar and finally 'pitch', tar of a consistency of road bitumen.
In the good old days tar was made by damaging the trees over 2-3 years. The lowest part of a pine was barked and only a hand's width of bark was left to keep the tree alive. The tree created a large amount of pitch, but most of it is inside the wood so just collecting the pitch wouldn't have been too productive. After several years of maltreating the tree it was felled. Also the stump was used, since it is the pitchiest part of the tree. Today the damaging is usually not done, they just get less tar for a certain amount of wood. And the forests are full of pitchy stumps to be used for tar after the trees have been harvested.
The wood is chopped to smaller bits and stacked to a tar pit. A tar pit is originally a cone dug out in the ground and covered with watertight (actually tartight) bottom with a hole in the lowest part to collect the ar. A big tar pit could have been 20 meters in diameter (22 yards). I found a site with original pictures about building a tar pit at http://www.paltamo.fi/koulut/kontio/terva/tervahau.htm . The pit was covered with peat and earth and set on fire so that it would burn with the minimum amount of air. If there was too much air all the tar would burn away, with less air it's like distilling solid firewood. Today usually a metal "tarpit" is used, the air flow is easier to control. A big pit could burn for two weeks and produce 5-10000 gallons of tar and large amounts of charcoal.
So tar is in fact liquid smoke, if you think of that. Pitch and turpentine is what keeps a growing tree from rotting alive, so tar is just the "natural rot preservatives" distilled out of the tree. It works brillianltly with pine, which is not an extremely rot resistant tree by its nature.
I don't know what's the "original pine tar" that was referred in the Woodenboat magazine, but "Stockholm tar" has been made long before they even found the whole America. It was mainly made in Finland (which was a part of Sweden those days) but as it was all sold through Stockholm, the name came and stayed. The poor swedes had burned most of their forests with their iron industry they came over to the periphery (Finland) and bought our forests in form of tar.
As for Wild Dingo's question: tar should be applied hot to allow it to soak into wood better. It's fairly thick as is and at least here the weather is still pretty cold when it's time to tar the boats. If you apply it cold, it'll just form a useless surface on the wood. You want to get it inside the wood, or at least the majority of it. Adding linseed oil helps on soaking in and as a bonus the tar doesn't get soft and sticky in the sun. On the other hand too much oil will destroy the best feature of tar: self-repairability. As tar softens in the sun it melts and fixes any cracks or small dents in the coating.
As an addition to the "odds and curiosities" list I just had a dish of tar ice cream at the local restaurant. We Finns still have a funny yen for tar, we have tar candies, different kind of tar-flavoured liquors, tar shampoo, heck I've even eaten marinated herring with a tad of tar. That tasted like smoked fish anyway.
01-17-2003, 10:27 AM
Thanks Pekka question asked and answered brilliantly! :cool:
Take it easy
01-17-2003, 02:09 PM
How is pine tar safely heated?
01-17-2003, 10:40 PM
Thanks Pekka, that was a great essay. Now I would like to know where my pine tar comes from marketed from Winnipeg. Canada, U.S., Sweden or Finland? Maybe China since the beans I had for supper tonight came, parellel packed, like sardines, in a plastic bag, from China! Dirk
01-20-2003, 08:01 AM
How to heat tar safely? I'd say that any way is safe enough as long as you have a lid for the tar kettle available for extinguishin the kettle. It catches fire every once in a while but you are not supposed to heat it that hot anyway. It has to come to a very slight boil. When light brown bubbles start to form on the surface boil it still a few minutes but not more. When it starts to smoke it's a bit too hot.
I've used open fire collected from the driftwood on the shore, gas cooker, paraffine cooker (which looked like a giant 2-flame oil lamp), kerosene blowtorch, even a disposable barbeque grill. They all worked although the open fire was a bit too much trouble because the high flames tended to light the tar a bit too often. With other methods I haven't had more than occassional problems.
Hard to thell where they make the tar these days. I have seen tar which was made with some sort of pyrolysis, not by burning the wood itself. It was horrid stuff, and it smelled like old burnt newspapers. There are not that many places where they are willing to see all the trouble for making proper tar.
01-20-2003, 09:00 AM
Hey! I remember that tar candy! I guess that's from growing up in the Midwest, where there's a large Scandanavian component to the population.
That was a great exposition on tar. Thanks!
01-21-2003, 08:33 PM
Originally posted by Pekka Huhta:
As for Wild Dingo's question: tar should be applied hot to allow it to soak into wood better.That's the way it goes on my [wooden] cross-country skis. I take a cabinet scraper to the sole of the ski and scrape the wax off. Sand lightly or repair the sole if it's been [inadvertantly] used as a mud/gravel ski. Ouch!
Then paint the sole with tar and take the ubiquitous torch w/flame spreader to it. Keep the torch moving and watch the tar bubble and flare and disappear into the wood.
Then let it cool a bit and take a piece of burlap and scrub any excess off.
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