Processing birch bark

If birch bark is stored correctly, i.e. as described below, and is not affected by external influences, birch bark can be used for almost any purpose. Store indefinitely. Birch bark should usually be used within three years, even if stored correctly.

Like wood and other organic natural products, birch bark is used by Weather, strong sunlight and moisture attacked. It is therefore important to store the birch bark in such a way that it remains as freshly harvested as possible.

It should be noted here that the bark is in a medium to cool room protected from sunlight is stored. Pay attention to a Good air circulation. The birch bark should not be packaged, especially not under plastic sheeting or similar to keep it away from fresh air. The humidity should be as stable as possible and not too dry, but also not too moist. Dry Air humidity deprives the bark of its natural moisture supply, it must then be be made supple again by soaking before processing. Excessive moisture can attack the mosses and lichens that often adhere to the bark and cause black spots on the bark. If the bark has come into contact with water, care must be taken to ensure that it can dry out properly.

Due to its high content of essential oils, birch bark is extremely Highly flammable. What can be of great use in the outdoor area during a rucksack hike when you want to light a campfire, requires great care when storing it. Birch bark should not be stored near hot objects (lamps, heaters and stoves, fireplaces and stovepipes...) and should never come into contact with fire.

For the most part, we supply our bark panels pressed flat. (Small order quantities are usually delivered rolled up.) This has the great advantage that the bark does not constantly roll up again and that it can be stored in a space-saving manner.

If bark is to be stored for a longer period of time, it should be stored flat. Make sure that if there are several sheets the same sides are on top of each otherThis means that the white outer layer lies on a white outer layer and the yellow inner layer lies on its own. This prevents Scratch markswhich can always occur during storage and transport.

Since the bark, even when lying flat, likes to rolls inthe top panels of a package are to be complainso that the rind retains its flat shape. Take particular care at the ends to prevent them from curling up by pressing. It is very difficult, if not impossible, to get rolled-up ends back into the desired shape.

Large pieces of birch bark, such as long lengths for making a canoe from birch bark, must be stored rolled up. This type of storage does not differ significantly from flat storage. As the bark usually loses its suppleness over time, it must be unrolled very carefully and repeatedly doused with hot water as it is unrolled.

Birch bark is as supple as leather, which is why it is often called birch leather. Nevertheless, particularly long, dry bark, from which the white layer is not yet detachedalong the longitudinal lenticels. Here too, tearing can be prevented by careful handling and hot water.

You can make the bark soft and pliable by soaking it in warm water (approx. 50°C). You can then (un)roll and bend the bark without the risk of it breaking. The bark only needs to be in the water for a short time, but you may have to repeat the process several times.

Once Bark soaked in warm water will always curl inwards, against the natural curve that the bark had on the tree trunk. The white side of the birch bark therefore always rolls inwards, while the warm golden-yellow layer can be seen on the outside.

With a little patience, the bark can also be made somewhat pliable in cold water, but never as pliable as with warm water. The bark warps much less in cold water.

Also for other processing stepsWhen punching holes for fasteners and seams, for example, but also when cutting threads and removing the white layer, etc., it is often helpful to make the bark pliable by soaking it in water, thereby making it more flexible. from brittleness.

Birch bark always tears in the longitudinal directionalong the lenticels (the dark slits on the bark) that are characteristic of birch bark. You have to be particularly careful at the side ends to avoid tearing the birch bark.

Birch bark lies in a multitude of layers similar to Onion skins around the birch trunk. At the Removing the bark from the tree the entire cork layer above the cambium is loosened.

Birch bark can usually be split cleanly into several layers over a large area by hand and the white layer removed. To do this, reach between the layers and remove the white layer to the desired thickness.

It is best to hold the birch bark board upright for this purposeThe structure of the lenticels runs horizontally. Now reach between the layers from above, carefully open the bark downwards on one side and finally pull it off to the side.

When peeling, the rind will always stick to the lenticels and become thinner and thinner in one direction. Make sure that this is the side that you do not want to process further (usually the white side).

You can re-grip the stuck areas and remove the excess bark again. Knives, e.g. flat, sharp knives such as pocket knives, Opinel... or even a sharp, only very slightly bent gouge, often help here.

You will also need the knives for the black growths and branches. You have to be very careful here, as protruding bark usually leads to a dent on the yellow side. Make sure that no holes are created here. Carefully remove the bark millimetre by millimetre. If the bark is bent with the yellow side facing outwards, the surface here will be even, but the inner white side can hardly be peeled off in this state.

Sometimes it also helps Warm water when peeling off the layers. However, it is generally possible to clean the birch bark when it is dry - grasp the edge of the bark between the onion skin-like layers and peel off enough to achieve the desired thickness.

We have learnt from experience that it is usually worth taking stronger pieces. This is easier to peel to the desired thickness than bark, which is already quite thin and therefore much more sensitive.

We grab always with strong pieces a few millimetres and then pull them off - This way you can quickly achieve a relatively even surface over a large area, i.e. if you remove a slightly thicker layer, it usually works quite well.

There are very different types of bark. The layers are very easy to remove from some pieces of bark and very difficult to remove from others. This depends on many factors - the nature of the bark, branches, dryness, age, etc.

Basically, you always have to reckon with quite a lot of waste with birch bark, partly because of the natural warping and knots, etc.

Birch bark can be combined with the natural white side outwards on various carrier materials such as Wood glued on be used. It should be noted that

• a) the sensitive surface is not attacked,
• b) Natural unevenness due to the pressure during gluing do not break

and

• c) the glue the extremely strong bark, especially at the edges.

a) Handle the birch bark with great care. The outer layer of birch is extremely resistant to weathering and external influences, as it is also constantly exposed to changing influences in the forest. However, visual changes caused by processing must be taken into account, in particular that the white surface is not permanently damaged by scratches or pressure marks. The white layers are also extremely thin and can be rubbed off easily, sometimes they look a little fuzzy. Make sure that the surface does not lose its natural charm.

b) Protect the birch bark from excessive pressure in the colouring process by adding something Upholstered becomes. To do this, place a cellophane film directly on the bark, for example. Place a very firm foam or similar cushioning material on top. This prevents dimensionally stable unevenness, such as that which occurs in the case of warping, from being crushed. Now apply pressure to the entire glue surface of the workpiece as usual.

c) Glue selectionBirch bark is extremely water-repellent. It only absorbs a little moisture at the characteristic longitudinal lines, the lenticels. Water-based glues (e.g. wood glue / polyvinyl acetate) therefore have a longer curing time than wood. Depending on the carrier material onto which the birch bark is glued, you should use a Use glue or adhesive that holds very firmly.
Birch bark has a tendency to curl sideways, against the natural surface tension on the tree. This means that birch bark always bends in the direction of the white outer layer. It is therefore particularly important that the side parts are glued extremely well and with a strong glue.

Our birch bark is untreated; we deliver them as if they were harvested from the forest. The surface is therefore not sealed, therefore offers absolute naturalness both visually and haptically. If you want a clean surface that does not release dust particles or fuzz, you can coat the outer layer of the birch bark with a non-glossy clear varnish. This will hold the loose elements of the white layers of birch bark.