The purpose of finishing is to paint the tubes and provide a good . The sanding methods depend on the epoxy system used.
West Systems
- Fill in any low spots in the tube with Bondo.
- Sand the tube, starting with 60 grit sandpaper and increasing to 120 and 220.
- Spray paint the tube with base coat (either universal bonding primer or automotive primer).
- Very lightly sand the tube with 220 grit sandpaper. If there are low spots, these will be visible because they will be the last to sand off.
- Repeat steps 1-3 for the low spots
- Very lightly sand the tube with 220 grit sandpaper not to sand off the base coat, but to smooth out any imperfections before paint is applied.
- Follow steps for painting
Fibreglast 3000
The epoxy is very hard and very smooth, making the epoxy hard to sand and apply bondo. We're currently trying this method:
- Apply base coat to the tube
- Sand the tube with 220 grit sandpaper to find low spots (as explained above)
- Apply Bondo to the areas that still have a layer of base coat
- Sand the Bondo to tube level with 60 grit sandpaper, 120 grit, and 220 grit
- Use a razor to cut off any excess epoxy on top of the tube
Paint
- Apply main paint coat
- Allow to dry for 24+ hours. Do not touch or sand prior to the gloss coat.
- Apply gloss coat
We have determined that the Rust-Oleum 2x Painter's Touch spraypaint provides a good surface finish, but would like to try a paint gun since the protective gloss coat does little to keep the rocket from getting scratched. The metallic paint will have small amounts of metal in it, but we have determined that this will not interfere with the avionics.