General Information Checking Surface Tension and Pre-TreatmentDosage, Mixture and SettingDifferent Processing MethodsCuring

Checking the Surface Tension

The surface tension is an indicator for the wetting properties of the surface the Ceralun should be applied to. A surface tension of at least 38 mN/m is recommended for working with Ceralun. It should also be randomly tested during production.

It is best to use the Test Pen (art. 9030/000) to measure the surface tension.

Note: On porous or absorbent materials, the surface tension cannot be checked with the Test Pen. If the Test Pen is used on highly polluted surfaces (e.g. grease, oil) or on material like wood, the Test Pen might be polluted as well and cannot be used anymore.


If the surface tension is below 38 mN/m, the following pre-treatment cleaning methods, applied in the correct order, can be effective in reaching the right level.

1Mechanical cleaning
This involves sanding, blasting or brushing but is not usually necessary for jewelry.
  • Removal of dirt, residues of varnish, rust, scale
  • Roughening the surface
2Washing and degreasing
Here it is important to ascertain that the tensides contain no silicone, as this would impair adhesion.
When using solvents it is advisable to test the durability of the surface to be cleaned beforehand to avoid any damage. Solvents containing substances with a high boiling point should not be used due to the high risk of residue. If using cleaning agents, wait a few minutes to allow them to evaporate.
  • Cleaning with tenside solutions, rinsing with de-ionized water
  • Cleaning with isopropyl alcohol/ethanol
  • Cleaning with acetone (MEK/ethyl acetate)
  • Cleaning with a cleaning solvent: should not contain high boiling point substances (risk of residue)
3Physical cleaning and activation
These cleaning methods can be applied if mechanical cleaning or washing and degreasing are either not possible or have not resulted in a surface tension of > 38 mN/m. Therefore the pre-treatment cleaning method used should be done on a case-by-case basis.
  • Flame treatment via a blow torch
    The surface to be treated is exposed to the flame of a torch very briefly. When using special gas mixtures, surface silication can also be carried out, so as to apply a more adhesive coating.
  • Corona treatment
    An electric corona discharge is briefly applied to the surface.
  • Plasma treatment
    Plasma treatment offers precise cleaning and activates the surface via an ionized gas.
4Chemical cleaning and primers
Applying a primer improves adhesion and helps to prevent corrosion.
  • Applying small amounts of solvent and activating the surface.
  • Applying a primer.