When you splice a replacement panel or a portion of a replacement panel to an existing panel, use the following procedure:

1. Clean and inspect the damaged area. Refer to General Plastic Repair .



2. Cut the damaged area and/or the replacement panel to the appropriate size so that the panel fills the opening.



3. Scuff sand the damaged area and the replacement panel's mating surfaces.



4. Fit the panel to the opening:

•	If the bonding strips are exposed, mechanically attach (1) and bond the strips together.

•	If the bonding strips are not exposed, cut or grind the edge of the panels in order to form a good butt joint (3). Then bevel the edges (2) to about 30 degrees in order to form a dished butt joint.




5. Install a backing patch (3). Refer to Backing Patch Fabrication .



6. Mix and apply, follow the manufacturer's instructions, a light coat of the repair material to the outside of the damaged area.



7. Lay a piece of reinforcement mat into the repair material.

•	The mat should extend 38-51 mm (1.5-2.0 in) beyond either side of the repair area.

•	All of the mat must be at a level below the final finished surface.

8. Using an applicator, saturate and remove any trapped air from the repair area.



9. Apply a second coat of the repair material in the same manner.



10. Lay a second piece of mat into the repair area in the same manner.



11. Apply the final layer or repair material in the same manner until the repair material (1) is at a level slightly higher than the surrounding area.



12. Cure the material according to the manufacturer's instructions.
13. Apply and cure additional layers as needed.



14. Rough out the surface using a #80 grit disc on a D A sander.



15. Apply a polyester type material to provide a uniform surface for sanding, such as Sikkens® Polystop LP, or equivalent.
16. Prime and refinish as necessary. Refer to GM 4901 M-D for a listing of approved materials. Follow the procedures recommended by the material manufacturer.