Cleaning and degreasing before coating and bonding: choosing the right cleaner
Bonding and coating only work on clean surfaces. Grease, release agents, or particles prevent adhesion; even the best adhesive or paint will fail under these conditions. This article explains which contaminants cause problems, which cleaners are available, and how to choose the right one.
To the point: why clean before joining
Adhesion occurs through direct contact between the adhesive or coating and the substrate. A thin layer of grease or release agent is sufficient to prevent this contact. Cleaning and degreasing are therefore not secondary steps, but prerequisites for a durable bond.
Which types of pollution are causing problems?
- Fats and oils from manufacturing, handling or corrosion protection.
- Release agents and silicone residuesthat specifically prevent adhesion.
- Particles and dust from processing and the environment.
- Old adhesive and sealant residues from repairs and maintenance.
Overview of cleaner types
| Cleaner type | fitness | Example from the product range |
|---|---|---|
| Solvent cleaner | fast, grease-dissolving, volatile | Technical acetone, special cleaner 750 |
| All-purpose and industrial cleaner | Gentle on materials, for machines and surfaces | Technomelt Melt-O-Clean |
| Special remover | Silicone and adhesive residues, hardened seals | Seal and Bond Remover |
| PU cleaner | fresh polyurethane residues | EN 705 and EN 706 PU cleaner |
Choose the right cleaner
Four questions guide the choice: What type of contamination is present? What is the substrate, and is it compatible with the solvent? What subsequent process will it be: bonding, coating, or painting? How residue-free does it need to be? Solvents can attack certain plastics, so check the compatibility with the substrate. The safety data sheet and the manufacturer's instructions regarding application and protective measures are crucial.
Proper cleaning: the steps
- Remove coarse dirt mechanically.
- Use a suitable cleaner and a clean, lint-free cloth, changing the cloth frequently.
- Clean several times as needed until the cloth remains clean.
- Allow the cleaner to evaporate and dry completely.
- Do not touch the cleaned surface with bare hands and process it quickly.
Typical mistakes
- Dirty cloth: the grease is spread instead of removed.
- If the cleaner is not allowed to evaporate, residues impair adhesion.
- Cleaned area touched again.
- Unsuitable cleaners damage the surface.
- Silicone or release agent residues not removed.
We'll gladly advise you on which cleaner is best suited to your substrate and subsequent process. For preparation, especially before gluing, and for removing residues, please see the linked articles.
