GYS Bumper Repair Kit User Guide

Quick guide from the manual

The GYS Bumper Repair Kit is designed to repair plastic car bumpers by melting a stainless steel mesh into the plastic to provide structural reinforcement, followed by filling with specialized brazing sticks. The core workflow involves identifying the plastic type, preparing the surface by grinding, melting the mesh into the plastic using a 550°C soldering iron, and finishing with sanding and primer.

Plastic identification

Before starting, you must identify the type of plastic to ensure the correct repair method:

• Thermoplastic: Symbols include PP, PE, PP/EPDM, TEEE, TPE, TPO, TPU, TPUR.
• Thermoset: Symbols include PUR, RIM, RRIM, EEBC.

Note that Thermoplastic and Thermoset bumpers require different repair approaches.

Preparation of the surface

Proper preparation is essential for a durable repair:

• Cleaning: Remove all grease from the part. Use soapy water; do not use solvents.
• Grinding: Use abrasive paper with grain 40 to grind the area. Avoid high rotation speeds to prevent the plastic from melting prematurely. A slight grinding is sufficient to remove paint or surface coatings.
• Mesh preparation: Cut a piece of the stainless steel mesh (ref. 052949) to cover the break, extending 3cm on either side. The mesh should be placed on the back of the bumper for reinforcement.

Repair process

Follow these steps to perform the brazing repair:

1. Position the stainless steel mesh over the break, ensuring edges are aligned.
2. Use the soldering iron (heated to 550°C) to melt the mesh into the plastic. Do not press too hard; the heat is sufficient to allow the melted plastic to rise through the mesh.
3. Allow the mesh to cool (compressed air can be used to speed this up).
4. If working on the front of the bumper, grind around the break and chamfer the edges.
5. Fill the area with JBDC brazing sticks (ref. 052956). Pre-heat the stick until it is melted on half of its thickness, then apply it like tin soldering.

Finishing

Once the repair is filled and cooled:

• Sanding: Remove excess material using grain 40 or 80 sanding paper. For a perfect finish, use ABRALON abrasive.
• Final steps: Clean and blow off dust, then apply a plastic primer. If there are minor surface defects, a specific plastic mastic may be used.

Safety and warnings

• Soldering iron: Never leave the iron switched on with the tip facing down, as the body may overheat and deteriorate.
• Ventilation: In case of poor air extraction, wear a breathing mask.
• Mesh quality: Only use the provided JBDC mesh. Generic steel mesh may oxidize, and aluminum mesh lacks mechanical resistance.

Compatibility

Not all materials can be repaired with this brazing process:

• SMC, Glass fiber, UP, FRP: Do not solder; these must be glued (use UV PATCH and FASTSEALER).
• ABS, PA, PC/PBT, PPO: Do not seal with the brazing process; these must be glued.