SAND MOULDINGS & INVESTMENT CASTINGS

Skellerns Foundry - Metal Casting Process

Skellerns Metal Casting is one of New Zealands top foundries for Green Sand Moulding, Hard Sand Moulding and Investment (Lost Wax) Castings using the lost wax process for detailed precision work.

Investment casting or Lost wax casting

As one of New Zealand last remaining investment casting operations we offer the full range from one off castings to high volume scale lost wax castings. From one off 3-D printed patterns to high volume parts through lost wax moulding we cover the range in 30 different casting metals either in non-ferrous or ferrous metals.

3D design and printing service

Skellerns Metal Castings also offer an inhouse 3D design and printing service for low volume economic investment cast patterns or high volume aluminium lost wax moulds. Our staff have more than 30 years’ experience in the investment casting process so there isn’t much we haven’t cast over this time.

Sand Moulding

At Skellerns Metal Casting Ltd we use 3 different types of sand-casting methods ensuring we match the most economically way to produce metal castings to your requirements.

Our casting methods in sand cover:

High Volume Shell Moulding
Medium Volume Green Sand
Low volume resin Hard Sand

Sand casting can produce metal to any size or shape eliminating the need for expensive engineering fabrication and wasted metal. Better still it is good for the environment as much of the metal is recycled metal.

Skellerns offers pattern services to help produce your patterns, we also have our own 3-D printer for those that want a low volume production pattern at low cost. Our casting range is from 20 grams to 500Kgs. We cast both ferrous and non- ferrous metals.

Sand casting is a versatile and creative technique that can be used for various purposes, from art, engineering and industrial parts. If you are interested in learning more about sand casting.

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.

At Skellerns we take great pride in our attention to detail and providing high quality metal castings and 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 Moulding

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.

Hard Sand Moulding

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

Investment Casting or Lost wax Casting

Investment Casting is a more accurate method for creating more precision for intricate castings. It would be used for small engineerings works, artwork and items that have under cuts.

Slightly more expensive – This method utilises high quality wax which is more expensive than Hardsand or Greensand.
Higher quality output – The use of wax creates greater precision in the metal casting end product.
Less additional work – the resulting metal cast product is more precise therefore less finishing is required