Skellerns is one of the top foundry’s in New Zealand for Green Sand Moulding, Hard Sand Moulding and Investment Castings using the lost wax process for detailed precision work.

This scope of expertise enables us to be more versatile and flexible when selecting the most appropriate methodology to achieve your desired metal casting outcomes.  

We take great pride in our attention to detail and our customer service.  

Working with Patterns

Castings from Existing Patterns

For bronze, aluminium and other metal castings, when you provide us with your existing patterns the Skellerns team will use their metal casting expertise and skills to ensure the highest quality and economical resulting products. 

Design & Process Guidance for New Patterns

Our experienced Sales & Support team will collaborate with you to ensure they understand all your requirements completely. With their wealth of industry knowledge they provide you technical guidance throughout the entire pattern design process and ensure it is prepared and ready to meet your timeframes.

Metal Casting Processes

Green Sand castings process is performed by using sand moulds formed from “wet” sand which contains water and organic bonding compounds, typically referred to as clay.  The “Green” of Green Sand Moulding is not in reference to the colour of sand but relates the sands state.  The name relates to the fact that the sand mould is not “set”, it is still in the “green” or uncured state even when the metal is poured in the mould.

Advantages of Green Sand Moulding:

  • This is the least expensive process when producing small quantities (normally less than 100) and also boasts with the least expensive tooling.
  • Range of casting sizes – ability to cast very large parts.
  • Flexibility in metal choice – Both ferrous and non-ferrous metals can be casted using this process.
  • Economical – A low production cost due to materials used and little post-casting tooling required.

Disadvantages of Green Sand Moulding:

  • Lower degree of accuracy – dimensional accuracy is less than that delivered by other processes.
  • Tolerances limitations – This process requires large tolerances. Surface roughness – The surface finish for ferrous casts delivered usually requires additional work.
  • Weight excess – Castings produced with this proceed usually exceeds the calculated weight.

The Hard Sand moulding process can have specific advantages over other manufacturing processes, which often lead to major cost savings, not only in the part price itself but also in the overall cost of production. Some of the benefits are in the processes flexibility:

  • Variety of metals able to be cast – ability to use both ferrous or non-ferrous metals.
  • Automated or hand crafted for accuracy – Mould replicates the component with high level of accuracy and consistency.
  • Jobbing or low volume production – ability to produce from 1 to 1000 units per run.
  • Complex shapes – undercuts and hollow centres can be formed and the process is capable of producing very large pieces.
  • Minimal wastage – Scrap and moulds can be and are often recycled