Bonding Pertinax with UHU Endfest and other 2-component adhesives: A guide

Bonding Pertinax with UHU Endfest and other 2-component adhesives: A guide

Pertinax, also known as hard paper, is a material that consists mainly of phenolic resin and cellulose and is often used in the electronics and model making industries. Due to its thermal and mechanical properties, it is well suited for applications such as circuit boards or insulation. But what is the best way to bond Pertinax, especially when using adhesives such as UHU Endfest or other 2-component adhesives? In this article, we take a look at the correct procedure and give tips on how to achieve a stable and durable bond.

1. Materials and properties of Pertinax

Due to its composition, Pertinax has a high strength and resistance to temperatures and chemical influences. However, it is relatively brittle, so an even distribution of the adhesive force is important. Pertinax surfaces can have low adhesion, so good pre-treatment is crucial to ensure optimal adhesion of the adhesive.

2. Selection of adhesive

Two-component adhesives are particularly suitable for bonding Pertinax. These offer high strength and temperature resistance, which is advantageous for the typical applications of Pertinax (e.g. in electrical devices or model building components). The most common options include:

• UHU Endfest 300: A 2-component epoxy-based adhesive that is particularly impressive due to its high temperature resistance (up to 180°C) and extreme strength (up to 300 kg/cm²). It is ideal for bonding Pertinax when high mechanical requirements are placed on it.
• Araldit 2-component adhesive: Another epoxy resin system that is also characterized by high strength and durability.

3. Preparation of surfaces

In order for the adhesive to adhere optimally, the Pertinax surface must be thoroughly prepared. The success of the bond depends heavily on the cleanliness and roughness of the surfaces to be joined.

1. Cleaning Service: First, the Pertinax surface should be thoroughly cleaned. Grease, oil or dust particles could affect the adhesion of the adhesive. It is best to use isopropanol or acetone to remove all contaminants.
2. Roughening the surface: Since Pertinax has a relatively smooth surface, it is advisable to roughen it slightly. This can be done with fine sandpaper (e.g. grain 400 to 600). Roughening increases the surface area, which leads to better adhesion of the adhesive.
3. Dedusting: After sanding, the surfaces should be cleaned again of dust particles, preferably with compressed air or a clean, dry cloth.

4. Mixing and applying the adhesive

2-component adhesives such as UHU Endfest or Araldit consist of two separate components (resin and hardener) that must be mixed together before use.

1. mixing ratio: Make sure to mix the components in the correct ratio (usually 1:1). Some products come with a mixing syringe that automatically adjusts the ratio.
2. Thorough mixing: Stir the two components well to ensure an even bond. This is crucial for the subsequent strength of the adhesive bond.
3. Instruct: Apply the mixed adhesive evenly to both surfaces to be joined. Be careful not to use too much adhesive as excess material may ooze out, leaving unsightly adhesive residue.
4. Put together: Press the two parts firmly together and hold them in position until the adhesive has hardened. With UHU Endfest, the processing time is around 90 minutes and the curing time is around 12 hours (at room temperature). Complete curing and maximum strength is achieved after 24 hours.

5. Curing and post-processing

The curing of a 2-component adhesive is chemical and usually takes several hours, depending on the room temperature. To ensure the best adhesion, the bonded parts should not be moved or loaded during the curing process. After curing, excess adhesive can be removed mechanically if necessary (e.g. by sanding).

6. Tips for successful bonding

• Pay attention to room temperature: If possible, bond at room temperatures of 20–25°C. Lower temperatures extend the curing time and may affect the bond strength.
• Even pressure: Ensure that the two Pertinax pieces are pressed together evenly to ensure a continuous and stable bond. A vice or clamp may be used.
• Avoidance of moisture: During the curing time, the adhesive should not come into contact with water or moisture as this could interfere with the curing process.

7. Conclusion

Bonding Pertinax with UHU Endfest or other 2-component adhesives is an efficient and permanent method of creating stable bonds. Through careful preparation of the surfaces, the correct mixing and application of the adhesive and a patient curing time, a high adhesive strength can be achieved. This means that even demanding applications in model making or electronics can be realized.