Resins, Tars, Natural Glues - Pine, Spruce, Birch - ID - anth >> .
The oldest known adhesive, dated to approximately 200,000 BC, is from spear stone flakes glued to a wood with birch-bark-tar, which was found in central Italy. The use of compound glues to haft stone spears into wood dates back to round 70,000 BC. Evidence for this has been found in Sibudu Cave, South Africa and the compound glues used were made from plant gum and red ochre. The Tyrolean Iceman had weapons fixed together with the aid of glue.
6000-year-old ceramics show evidence of adhesives based upon animal glues made by rendering animal products such as horse teeth. During the times of Babylonia, tar-like glue was used for gluing statues. The Egyptians made much use of animal glues to adhere furniture, ivory, and papyrus. The Mongols also used adhesives to make their short bows, and the Native Americans of the eastern United States used a mixture of spruce gum and fat as adhesives to fashion waterproof seams in their birchbark canoes.
In medieval Europe, egg whites were used as glue to decorate parchments with gold leaf. The first actual glue factory was founded in Holland in the early 18th century. In the 1750s, the English introduced fish glue. As the modern world evolved, several other patented materials, such as bones, starch, fish skins and isinglass, and casein, were introduced as alternative materials for glue manufacture. Modern glues have improved flexibility, toughness, curing rate, and chemical resistance.
A natural resin is the sticky substance that seeps out of some trees and plants. Its purpose in nature is to protect the tree from invading insects and diseases. As the resin hardens over time and becomes waterproof, it will bind materials together. These properties allow people to use natural resins as a source of glue. There are two types of natural resins that are most commonly used to make glue: pine resin and birch tar, with pine being the easiest material to use.
About Pine Resin
Pine resin seeps from the tree anywhere the tree has been injured. It has a clear or slightly yellow look to it. It is often covered in dirt, bark and other debris which needs to be removed before the resin can be used as glue. Pine resin is not the same as pine sap. Sap is the sugar-based substance that feeds the tree. It runs up the interior of the tree from the roots out to the leaves. Natural resin originates from sap but is an entirely different substance.
It has been used as a glue since ancient times, including by the Egyptians in mummification. It is a thermoset glue, meaning it has to be heated to be used. As it cools, it hardens and binds. Pine resin (and most natural resins) are soluble in alcohol, not water, and when dry, pine resin is waterproof.
Making Pine Resin Glue
You can collect pine resin from a pine tree by scraping a bit of the bark until the tree seeps out a bit of the resin. Use an old knife to scrape and then collect the resin. Separating the resin from the debris can be done in any of three ways. You can boil it and as it heats, you can scrape the debris to the side, separating the pure resin from the debris. You can use a metal funnel with a very small opening in one end, through which the pine resin will drip while the debris stays in the funnel. Or you can boil the resin in a cloth bag. The resin will rise to the surface and separate from the debris. When using any of these methods, you can then create a ball with your resin for storage.
Mixing pine resin with charcoal, beeswax or a combination of the two helps to strengthen the glue and makes it less brittle. You can try different ratios to test what works best, but a ratio of 2 parts resin to 1 part charcoal works well.
Birch Resin Glue
Birch resin, located on the bark of birch trees, has been used as far back as the Roman Empire, according to an article in New Scientist. One method used to make birch resin glue involves an outdoor fire. To make the glue, collect strips of birch bark and roll them together until you have enough to fill a round metal container with a small hole punched in the bottom. A cookie tin approximately 12 inches in diameter will work. Dig a hole in the ground about the size of the can. Place a similar-sized can in the hole in the ground, and place the cookie tin full of birch bark on top, with the hole directly above the other can. Collect sticks and pieces of wood and place them around the cookie tin to make a fire which will heat the birch bark. You must know basic fire-making skills to use this method. Light your fire and keep it burning but not too hot for about 30 minutes. As the can heats, the resin will drip into the receptacle. When you notice that no more resin is dripping into the receptacle, carefully remove the cookie tin full of birch bark and then carefully remove the receptacle from the hole in the ground. This is then boiled down, which you can do in a double boiler on your stove, for a few hours until the resin is sticky enough to collect. You can collect it by swirling a stick around the inside of the receptacle and store it, hardened, on the stick.
Read more: Natural Resin for Glue Making | eHow.com http://www.ehow.com/way_5761915_natural-resin-glue-making.html#ixzz1DiBoPxIe
