Phase 2: Bottom-Up Layup & Hole Drilling

Status: In progress — may change based on actual experience. Work is underway but progressing slowly and may not be complete until August 2026. Steps are being revised as the work progresses.

1. Prep the Mold

  1. Cut a 65” x 16” melamine board for the base. Screw a second melamine layer on top with silicone caulking between the layers to form a 55” x 13½” mould, and fill all corners with silicone caulking.
Base melamine layer, 65" x 16".
Base melamine layer, 65" x 16".
Second melamine layer screwed on top with silicone caulking.
Second melamine layer screwed on top with silicone caulking.
  1. Verify the mould is square before the silicone sets.
Verify the mould is square.
Verify the mould is square.

  1. Leave the mould open on three sides — the metal frames are not perfectly straight, so the open long side lets you clamp the panel true.

  2. Once the silicone is dry, place the first panel in the mould and clamp the long sides straight. Run a bead of silicone caulking along the outside of the bottom and both ends of the panel frame to seal the resin inside while still allowing the long edges to be straightened and the panel to de-mould cleanly.

Panel in the mould with clamps straightening the long sides.
Panel in the mould with clamps straightening the long sides.

Note: It might be easier to install and remove one of the long sides instead of using silicone on each panel.

2. Wet Out the Fiberglass

  1. Measure out 16 oz of resin. Warm the two resin parts in a hot-water bath to improve mixing and flow.
Resin measured out for the back-skin pour.
Resin measured out for the back-skin pour.
Add color now if needed — note that color adds conductivity and requires additional conductive isolation for the solar cells.
Add color now if needed — note that color adds conductivity and requires additional conductive isolation for the solar cells.
  1. Lay the fiberglass cloth into the bottom of the panel.
Fiberglass laid into the mould.
Fiberglass laid into the mould.
  1. Mix the resin and hardener and stir for the time recommended by the resin instructions.
Mix resin and hardener, stirring for the full recommended time.
Mix resin and hardener, stirring for the full recommended time.
  1. Pour the 16 oz of resin over the fiberglass and squeegee it in, working out all the air pockets under the cloth.
Pour resin over the fiberglass and wet it out fully.
Pour resin over the fiberglass and wet it out fully.
  1. Let the back skin cure for 24 hours.
Cured fiberglass back skin after 24 hours.
Cured fiberglass back skin after 24 hours.

3. Remove Amine Blush

Epoxy produces a waxy byproduct called amine blush as it cures. Wash the cured fiberglass skin with warm water, dish soap, and a Scotch-Brite pad. Dry completely.

4. Drill Wire Exits

Measure exactly 2 inches inward from the steel frame on the cured back skin. Drill two holes just wide enough for your flat bus wire to pass through.

Previous: Phase 1 — Frame Prep & Bonding Surface Next: Phase 3 — Cell Placement & Routing

Content licensed under CC0 1.0 — see LICENSE.