Hempstone

Hempstone is an organic material that forms a solid body by only using hempfibers and water. It was developed and patented in the 90’s.

 

It was used and perfected by Norbert Schmid from austria, who makes mainly Didgeridoos and Djembe out of Hempstone.

 

He has worked with the material for over 13 years and he is very interested in working with designers, artists and instrument makers

 

You can learn more about him and his work on his website: Drumparam.at

The remarkable aspect of Hempstone is not only the strengt and hardness, that compares to woods like hardmaple and ebony, but also the absence of any artificial binders.

It consists purely out of ground hemp fibres and water. There is no artificial binder needed.

Mineral pigments can be added to acive the desired colour.

The secret that turns hempfibres into this solid material lies in the way it is processed.

By grinding and splitting up the fibres to a very high extend, the surface is enlagred expotentionally.

“When water is added intermolecular hydrogen bonds are formed between the fibres.” (Norbert Schmid).

It is the same effect, that makes Paperfibres stick together, even thought to a much stronger extend.

The fibres are sprayed on a mold in serveral layers.

When the pulp dries the hydrogen bonds are formed and the material shrinks up to one tenth of its volume, creating a very dense material.

Norbert Schmid and Jakob Frank at the Drumparam Workshop in Lafniz, Austria

Hempstone bodies at the Drumparamworkshop in Lafnitz, Austria

The molds have to be shaped round. Any sharp edge or irregularity in the material can create tears in the material.

Additional pulp is sprayed to the bottom of the mold to compensate for the pulling forces created by the immense shrinkage.

After drying several days the bodys are ready to be seperated from the molds for further preperation.

When dried, the Hempstone is quiet rought.

Because of the shrinkage and application process craters are formed. Through further preparation, these crates are smoothend creating the typical hempstone surface.

If desired, the body can be sanded to create a smooth surface.

 

The Hempstone is so hard that an anglegrider can be used to sand it.

After some steps to further enhance the colour with oil paint and drying oil the bodys are finish using some shellack.

The finished bodies consist out of hemp fibres, water, pigments, oil and shellack. Because of the applying method the colour has a lot of depth and complexity.

The textured bodies aso are very resistant against any kind of scratches or impacts.

hempfiber pulp after grinding process

Hempstone sprayed on mold by Norbert Schmid

Hempstone bodies in drying camber in Lafnitz

raw Hempstone body

warping as a result of high shrinkage

finished body

colour depth and spectrum

plane surface

structure on the inside