- (AKA Rumbler bells, sleigh bells, or hawk bells)
By: Jurgen Weiter von Landstuhl
Crotal bells have been used throughout Europe, and have been found in digs from Roman territories to Scandinavia. They have been used for many different purposes, such as falconry, horse bridles, fashion accessories, and even pilgrimage souvenirs. An example from Gotland, Sweden, was found attached to a seneschalate style chain. In the 14th century Richard II started wearing them attached to his belt (a fashion borrowed from continental Europe). Crotal bells were also worn in times of festivities and as an expression of courtly romance. Bells of this type have also been documented as being worn by pets and hunting dogs, and in one 13th century example by the horses participating in a joust. The bells I have made are of a construction method dated to the fifteen hundreds, but the usage would have remained similar to earlier examples.
They have been found having been produced in Tin, Copper, Brass, Bronze, and Pewter, and occasionally in more rare circumstances in metals such as Gold and Silver. I have chosen to cast mine from Pewter. Bells were manufactured in several different ways throughout their history. They were sometimes cast as multiple pieces, and then welded together. Sometimes they were cast as just two pieces (an upper and lower half) that were then either welded or crimped in the middle. These parts could either be cast or made by hammering sheet into forms. Some bells were also cast as one piece then bent closed after the pellet is inserted. The method I chose was pioneered in the fifteen hundreds, and consists of casting a one piece bell that has the pellet already in the centre by way of sand casting, creating a stronger bell overall.
The method of casting one piece bells is as follows;
First, a bell form must be made, consisting of a solid bell carved or cast. It will be used to form the sand around. This form must have indentations in the upper part of the bell, to form the braces for the core, as well as the bottom slit for the core to rest on. A removable pouring sprue must also be made, which will allow a loop to be included in the cast.
After making a mold box or form, the bottom half is then filled with foundry sand and packed tightly, mounting the bell blank halfway into this layer. Then a layer of talc is dusted onto this, to allow the halves of the mold to be separated easily. Then the top part of the mold is placed onto the form, and also packed with sand around the top of the bell and the sprue. At this point, I also added vent holes by pressing wire forms into the top of the mold, and added two pins (which will stay in place during the casting) through the indentations in the top of the bell form. These will be used later to secure the core.
Next, the mold is separated, and the vent pins, sprue, and bell form are removed. Any excess sand is blown away as to not contaminate the mold. I then at this point added a personal modification to the process by adding two clipped pins to the mold straddling the slit brace at the bottom of the mold. I used these to secure the core from moving within the mold. Additionally, after the separation of the molds during the mold making process, but before the core is introduced, designs can be pressed into the bell’s face using punches and tools if desired.
At this point, a round sand ball is formed around a tin or steel pellet and packed tightly. This will be used as the core in order to cast the hollow bell and allow the pellet to be cast inside the bell. This core is then inserted into the mold (onto the pins I inserted) and the two halves of the mold are placed back together. At this point, the two pins I added that go through the upper indentations are pushed gently into the core. The purpose of this is that after many failed casting attempts, I discovered that as the pewter was poured into the mold the sand core was attempting to float on top of the metal and bringing it to close to the top of the bell. These pins hold the sand core down and in place.
The mold is then ready to be used, and the bell is poured in the usual fashion. After being poured and cooling, the bell is drilled in the proper places, and the slit widened at the bottom to the appropriate size. Then using some tool (in my case a bent wire scoop with a round loop at the end that I made), you break the sand of the core apart and knock/blow it all out, leaving the bell’s cavity clean and the pellet behind and unable to be removed. The bell can then be cleaned, filed, additionally drilled, and polished as desired.
Egan, Geoff, and Pritchard, Francis, Dress Accessories c.1150-c.1450 (MoL 1991) ISBN 978 1 84383 351 2
Mitchiner, Michael, Medieval Pilgrim & Secular Badges (Hawkins Publications, 1986) ISBN 0 904173 19 4
UK Detector Finds Database: http://www.ukdfd.co.uk/pages/crotal-bells.html