Cast-on technique or “Überfangguss“: examples from the Middle Bronze Age in Denmark and Northern Germany.
‘Cast-on’ means the mechanical connection of two cast pieces by embracing or clasping these two parts through a third part that is subsequently cast on. This technique is mainly used to produce large, complicated artefacts and often viewed as a repair technique. In most cases, however, the cast-on technique is deliberately chosen to craft such special items more quickly and easily, where otherwise it would need an extraordinary mould construction.Drescher 1958 (translated by H. Nørgaard)
Casting on a perforated plate:
The perforation of the belt plate from the back seemed to be the preferred mode of operation. The resulting slight ‘throat’ on the reverse side served to engage the eyelet in the disc and was occasionally used as a limitation for the modelling of the eyelet. On the belt plates of Vognserup Enge (see above VM1680KD and VM1680KC), Svenstrup (see above, NM 10931) Langstrup (see above, NM B2307)) on Zealand and Gollern (see above, LMN 4753) in Lower Saxony the traces of connection between the eyelet base and the already cast disc are easily recognisable. On a few artefacts traces are documented that leave questions on how the perforation of the disc was performed. On the belt plates from Gerdrup (see above, NM11459-2) and Frankerup (see above, NM CMXII) the eyelet was very well prepared before it was attached to the cast plate. The cast was exemplary in both cases. It can be assumed that a very large hole (in the centre) had to be filled, especially regarding the belt plate from Frankerup (NM CMXII), as the cracks on the edges are still clearly visible. Additionally, it can be assumed that the attached spike and eyelet could not meet the weight of the disc and consequently that the first attempt had to be repaired (like on the Frankerup plate).
On some artefacts, the impression of the tool that attached the malleable material to the metal disc, probably a wooden spatula, is partly visible.
A feature recognisable on all examined bronzes is the leakage of surplus material due to a slightly larger cavity. On the Rye disc, the surplus material was cut off post casting.
The direction of casting the spike:
For a DANISH version see my article “Bronzealderens Mesterstøbere“
Conclusions could be drawn concerning the direction in which the casting occurred. The spike of the belt plate from Grabow is cast from the eye, as Drescher states, whereas the spike of the Langstrup plate was probably cast from the tip of the spike.
Upon closer examination of the specific discs it could be detected that the surplus material on the belt plate from Grabow does not come out at the reverse side but between the base of the spike and the disc. A contrary picture occurs with the Langstrup plate. Furthermore, the spike of the belt plate found in Svenstrup displays clear traces of reworking on the tip (removal of the sprue) and confirms the casting from the face side.
Here, also, the surplus material comes out between eyelet and disc. Consequently, a cast were the sprue was attached to the spike can be assumed for the belt plates from Vognserup Enge (1680 KC and KD), Svenstrup, Langstrup, Rye, and possibly Frankerup (CMXIII) on Zealand. Presumably the second belt plate from Frankerup (CMXII), the second belt plate from Gerdrup (B11459-2) and from Annebjerg Skov (B997) on Zealand are cast from the reverse side (the eyelet), similar to the plate from Grabow.