Making Quality Visible – Corrosion Testing for Decorative Finishes
An Overview of Our Corrosion Testing Methods
A decorative finish should not only look high-quality – it must also maintain its performance under real-life conditions over the long term. Sweat, moisture and sulphur-containing atmospheres can attack plated surfaces, leading to discolouration, corrosion and ultimately a reduced service life.
To reliably assess the durability of electroplated coatings, IWG offers a range of standardised corrosion tests. We carry out these tests both for our own coatings and as an external testing service for our customers.
Artificial Sweat Test
Jewellery, watches, eyewear and writing instruments are exposed to human sweat on a daily basis. The composition of sweat can attack metal surfaces, causing discolouration and corrosion.
During the artificial sweat test, components are exposed to a defined test solution that simulates human perspiration. Depending on customer requirements, different standards or customised test conditions can be applied.
This test is particularly suitable for assessing:
- Colour and gloss stability
- Corrosion resistance of decorative coatings
- Resistance to everyday wear and use
In addition, immersion in artificial sweat can be used to quantify the release of unwanted metals, such as potentially allergenic nickel.
SO₂-Test (Kesternich-Test)
The SO₂ test simulates a sulphur dioxide-containing atmosphere with high humidity. These conditions accelerate corrosion processes and allow a realistic assessment of the protective performance of electroplated coatings.
Test specimens are subjected to cyclic exposure in a defined atmosphere containing sulphur dioxide and condensation moisture. They are then evaluated for corrosion, discolouration and coating damage.
The Kesternich test is widely used for assessing decorative surface finishes.
H₂S-Test
Silver and silver alloys are particularly sensitive to hydrogen sulphide (H₂S). Even low concentrations can cause the well-known tarnishing effect on the surface.
The H₂S test accelerates this ageing process under controlled laboratory conditions, enabling a rapid assessment of the tarnish resistance of coatings.
Typical applications include silver or silver-alloy coatings on:
- Jewellery
- Watches
- Decorative metal surfaces
Corrosion Testing as an External Service
IWG does not use these testing methods solely for the quality assurance of its own coatings. We are also pleased to test customer components, samples or production parts – regardless of where the coating was applied.
Our services include:
- All common corrosion tests according to your requirements
- Evaluation and documentation of test results
- Expert support in the interpretation of test data
With our testing procedures, we help you reliably demonstrate the quality and long-term durability of your decorative finishes while identifying opportunities for optimisation at an early stage.
