If your laboratory uses a Claisse fluxer for borate fusion sample preparation, choosing the right platinum crucibles and molds is essential for accurate, repeatable XRF and ICP results. Claisse fusion machines — including the popular M4, TheOx, and LeNeo models — require precision-engineered platinum labware that meets exact dimensional and alloy specifications.
In this guide, we cover everything you need to know about selecting, maintaining, and sourcing Claisse-compatible platinum labware — whether you’re outfitting a new instrument or replacing worn crucibles and molds in an existing setup.
Why Claisse Fluxers Require Specific Platinum Labware
Claisse fusion machines are engineered with precise heating profiles, pouring mechanisms, and crucible cradle dimensions. Unlike generic laboratory crucibles, Claisse-compatible labware must match exact geometric tolerances to ensure proper seating in the heating position, consistent heat transfer, and reliable automated pouring.
Using incorrectly sized or poorly manufactured crucibles can lead to:
- Incomplete fusion due to uneven heating
- Spills and sample loss during the pouring cycle
- Accelerated crucible degradation from improper fit causing mechanical stress
- Inconsistent glass disk thickness that affects XRF measurement accuracy
This is why laboratories should source their platinum labware from suppliers who manufacture specifically to Claisse specifications — not generic “one-size-fits-all” crucibles.
Claisse Fluxer Models and Their Labware Requirements
Claisse M4 Fluxer
The M4 is Claisse’s high-throughput workhorse, capable of preparing four samples simultaneously. It uses standard Claisse-profile crucibles (typically 30–35 mL capacity) and flat-bottom molds designed for the M4’s specific pouring and cooling stations. The M4’s automated tilting mechanism demands crucibles with precisely formed pouring lips to ensure clean, consistent pours.
Claisse TheOx Advanced
TheOx Advanced is designed for demanding applications including loss-on-ignition (LOI) determination and fusion in a single instrument. Its labware requirements are similar to the M4 but may include specialized crucible configurations for LOI workflows. If your lab performs loss on ignition testing, ensuring your crucibles can withstand repeated high-temperature LOI cycles is critical.
Claisse LeNeo Fluxer
The LeNeo is a single-position fluxer popular in smaller labs and educational institutions. While it uses the same Claisse crucible profile, its single-sample design means each crucible sees more thermal cycles per unit of time in high-throughput environments, making alloy selection and crucible quality even more important for longevity.
Platinum Alloy Options for Claisse Labware
The alloy composition of your platinum crucibles directly affects their performance, lifespan, and compatibility with different sample types. For Claisse fluxers, the most common options include:
Pt/Au 95/5 (Platinum-Gold)
The industry standard for most borate fusion applications. The 5% gold addition improves non-wetting properties, making glass beads release more easily from molds. This is the recommended alloy for most borate fusion sample preparation workflows.
Pt/Au 97/3 (Platinum-Gold)
A lower gold content option that offers slightly better high-temperature mechanical properties while still providing adequate non-wetting behavior. Some laboratories prefer this alloy for applications involving higher fusion temperatures.
Pt/Rh 95/5 (Platinum-Rhodium)
Rhodium-alloyed platinum offers superior mechanical strength at elevated temperatures and better resistance to certain aggressive sample types. However, it lacks the non-wetting benefits of gold-alloyed platinum, so glass bead release may require additional attention. For a deeper comparison of alloy types, see our guide to platinum crucible alloy selection.
Custom Alloy Compositions
One advantage of working with a specialized supplier like SIB Fusion is the ability to order custom alloy compositions tailored to your specific application. Whether you need a unique Pt/Au ratio, Pt/Ir blends for extreme-temperature work, or other precious metal combinations, custom alloys can optimize performance for challenging sample matrices.
Crucibles vs. Molds: Understanding the Difference
Claisse fluxer setups require both crucibles and molds, and each serves a distinct purpose:
Crucibles are where the actual fusion takes place. The sample and flux mixture is loaded into the crucible, heated to fusion temperature (typically 1000–1100°C), and agitated to create a homogeneous melt. Crucibles endure the most thermal and chemical stress and are the labware component most likely to need replacement.
Molds receive the molten glass bead after pouring. They shape the fused sample into a flat disk suitable for XRF analysis. Molds experience less thermal stress than crucibles but still require high-quality platinum to produce smooth, defect-free glass disks. Learn more about recognizing when your labware needs replacement.
Key Specifications to Check When Ordering
When sourcing replacement or additional platinum labware for your Claisse fluxer, verify the following specifications:
- Dimensional compatibility: Outer diameter, height, and lip profile must match your specific Claisse model
- Alloy composition: Confirm the Pt/Au or Pt/Rh ratio suits your sample types
- Wall thickness: Thicker walls last longer but cost more; typical range is 0.8–1.2 mm
- Surface finish: Smooth interior surfaces improve glass bead release and reduce cleaning time
- Weight tolerance: Consistent weight ensures reproducible fusion conditions across multiple crucibles
- Certification: Material certificates confirming alloy purity and composition
Maintaining Your Claisse Platinum Labware
Proper maintenance extends the life of your platinum crucibles and molds significantly. For Claisse-specific labware, follow these best practices:
- Clean after every use with dilute HCl (10–20%) to remove residual flux and sample material
- Inspect regularly for thinning, pitting, or deformation — especially at the pouring lip
- Avoid contact with base metals (iron, nickel, copper) which can alloy with and weaken platinum
- Never use metal tongs directly on platinum surfaces — use platinum-tipped or ceramic-coated tools
- Store separately in individual padded containers to prevent scratching
- Rotate crucibles in multi-position fluxers like the M4 to distribute wear evenly
For a comprehensive maintenance protocol, refer to our complete platinum crucible care guide.
The Value of a Platinum Buyback Program
Even with excellent maintenance, platinum labware eventually reaches the end of its useful life. Rather than discarding worn crucibles and molds, laboratories can recover significant value through a platinum buyback program. SIB Fusion offers competitive buyback rates on used platinum labware, which can offset 30–50% or more of the cost of replacement pieces.
This is particularly relevant for Claisse users running high-throughput operations where crucible replacement is a regular operating expense.
Why Source Claisse-Compatible Labware from SIB Fusion?
SIB Fusion manufactures Claisse-compatible platinum crucibles and molds to exact OEM specifications, ensuring perfect fit and performance in your M4, TheOx, or LeNeo fluxer. Key advantages include:
- Exact dimensional compatibility with all current Claisse models
- Multiple alloy options including custom compositions for specialized applications
- High-purity materials with full certification documentation
- Competitive pricing compared to OEM-branded labware
- Platinum buyback on your worn-out crucibles and molds
- Global shipping with responsive technical support
Whether you’re replacing a single crucible or outfitting an entire fleet of Claisse fluxers, browse our full range of platinum labware or contact us for a quote tailored to your laboratory’s needs.