Instructions for processing: Birch bark handles with the help of a Birch sapling stakes Make yourself.
View through a microscope
First, a look through the microscope, specifically at the „forehead edge“ of the bark:
Birch bark consists of a variety of individual layers. Layers of large, honeycomb-shaped cells with thin walls alternate with layers of smaller cells with distinctly thicker walls. This so-called „sandwich structure“ makes the bark relatively light, as well as exceptionally elastic and tough.
If we look at the bark from above / outside, we see the characteristic black streaks, the so-called lenticels. These are very large cells that make the bark breathable.
To protect the tree from pests even under the worst growing conditions, the bark contains, in addition to waxes and oils, various ingredients that can very effectively ward off fungi, bacteria and viruses, and also make the bark water-repellent and weather-resistant.
All this gives birch bark technical properties that allow it to compete with many modern plastics.
The cell structure and ingredients described above lead to some particularities that need to be considered during processing.
Machining the blank
The bark is relatively easy to split between the individual cell layers. For the blank, this means that excessive shear loads in the direction of the layers (i.e., at right angles to the inner bore) can lead to breakage. You can avoid this by fitting your product with a core. This can be the tang of a knife blade, the blank of a fishing rod, a metal tube, or simply a wooden core. The higher the expected load, the stronger the core should be chosen. If you only want to assemble your product after shaping, we recommend working with a provisional core during processing, for example, in the form of a round rod.
Connecting blanks:
Several blanks, or parts thereof, can be glued together with simple white glue (wood glue) or bonded with epoxy resin.
Machining
Due to the elastic flexibility of the bark, we recommend working with a sharp tool. All woodworking tools are generally suitable.
Grinding
Due to its high oil and wax content, birch bark tends to clog abrasives relatively quickly. You can quickly clear abrasive pads, discs and belts of sanding machines again with a piece of rubber. For hand sanding, especially if you want to achieve a final, velvety surface, we recommend wet sanding with water or oil.
Surface protection:
Technically speaking, the bark does not require any surface treatment, as its natural constituents already provide excellent protection. However, with the right treatment, both its beautiful texture can be shown off to better effect and care made easier. In this case, please use only products that a) are not too thick and b) do not seal the surface!
Tip: Nappy care oil
We recommend nevi care oil. This oil harmonises excellently with the ingredients of the bark due to its very high-quality components. Due to its very small-molecule structure, it penetrates the bark's capillaries exceptionally well without sticking them together. It remains breathable.
You only need a very small amount of this oil. It can either be applied with a soft cloth or used directly as part of a final wet oil sanding process. This will give you a very attractive and low-maintenance finish.
Care
As a natural product, birch bark ages depending on the intensity of use and environmental factors. Over time, it develops an amber-coloured patina and gradually darkens, much like well-used wood. Where this patina is undesirable, occasional cleaning with lukewarm water, mild soap and a soft sponge is usually sufficient.
However, please do not use harsh cleaning products! In strong UV light, on the other hand, the bark lightens in colour, becoming similar in hue to ripe grain. After several cleanings, we recommend lightly re-oiling the surface with nevi care oil.
Refit: For more significant signs of wear due to prolonged, intensive use, or after extended exposure to UV light or weathering, a refit can be carried out by lightly sanding with a fine-grained wet sandpaper. Of course, we also recommend nevi care oil for this purpose.
Tip: Leave natural
Technically, no maintenance or refitting is absolutely necessary. The durability of objects made from raw blanks of nevi quality will continue to bring joy to your great-grandchildren, even without any care, within the intended scope of application.
Resistance to moisture:
The resistance to salt water and moisture is extremely high. However, we recommend avoiding prolonged exposure and allowing the material to dry out regularly. In principle, use in damp rooms is possible. Standard ventilation is sufficient here.
Birch bark handle blanks can be found in our shop on this page.