Materials
Materials List
Everything needed to build the 55” × 13½” × ½” steel-framed solar panel. Volumes are calculated from the panel geometry with a small buffer.
Costs are listed as Estimated (planned/budgeted) and Actual (paid where known). Consumables (welding wire, paint, cleaning solutions, etc.) are excluded — they fall within ~5% of overall cost. An em dash (—) means no estimate was set; TBD means the cost is unknown.
| Item | Estimated | Actual |
|---|---|---|
| Steel L-Beams | — | ~$20/panel ($2.40/ft, pre-cut) |
| Cross-Beams | — | ~$9.50/panel ($2.90/ft, pre-cut) |
| Solar cells (6” × 6”, 16 per panel) | — | $12.80/panel ($0.80 each) |
| Junction box (w/ cable & connectors) | $20 each | TBD |
| Resin (UV-stabilized marine epoxy, slow hardener) | $41/panel ($34/gal) | TBD |
| Mold surface (18” × 60” melamine board) | $25 | TBD |
| Epoxy metal primer | TBD | TBD |
| Fiberglass cloth (6oz woven, 55” × 13¼”, enough for all 4 panels) | $8 | TBD |
| Non-sulfur modeling clay | $3 | TBD |
| Marine-grade silicone | $10 | TBD |
| Tabbing wire, bus wire, flux pen, soldering iron (enough for all 4 panels) | $15 | TBD |
Total estimated cost projection
Full project cost for 4 panels. Per-panel items (steel, cross-beams, solar cells, junction box, resin) are multiplied by 4; shared one-time items (mold surface, clay, silicone, fiberglass cloth, tabbing wire kit) are counted once. Uses actual cost where known, estimate otherwise. TBD items (primer) are excluded and noted.
| Line item | Cost |
|---|---|
| Subtotal of known items | $474.20 |
| Consumables (~5%) | $23.71 |
| Buffer (~10%) | $47.42 |
| Total estimated cost | $545.33 |
Excludes: epoxy metal primer (TBD). TBD items are not included in the subtotal; adding them later will increase the total.
Structural & Mold
- Steel L-Beams: 54⅞” × ½” × ½” (length is ⅛” shorter than the panel width at the shortest point — referred to as ~55”).
- Cross-Beams: 3× flat steel bars, 13” long, ⅛” thick.
- Mold Surface: 18” × 60” melamine board.
- Epoxy Metal Primer: Automotive self-etching primer or 2-part epoxy primer.
Composite & Resin
- Fiberglass Cloth: 6oz woven fiberglass cloth, cut to 55” × 13¼”.
- Resin: UV-stabilized clear marine epoxy resin + slow hardener (2-gallon kit; you will use ~1.13 gal + buffer).
- Layer 1 — Fiberglass + epoxy resin + black dye: 12½” × 55” × ⅛” = 85.94 in³ (resin = 83.79; fiberglass = 2.15) ≈ 0.363 gal (≈ 46.5 fl oz).
- Layer 2 — Three cross-beams + epoxy resin: 13¼” × 55” × ⅛” = 91.09 in³ (resin = 86.22 in³; cross-beams = 4.88 in³) ≈ 0.374 gal (≈ 47.8 fl oz).
- Layer 3 — Solar cells.
- Layer 4 — Resin flood: 13¼” × 55” × ⅛” = 91.09 in³ ≈ 0.394 gal (≈ 50.5 fl oz).
- Non-Sulfur Modeling Clay: (e.g., Plastilina or non-sulfur plasteline) for sealing wire passthroughs.
- Marine-Grade Silicone: For the top expansion cap and J-Box mounting.
Electrical
- Solar cells, sized to fit inside the 55 × 13.5 frame.
- Tabbing wire, bus wire, flux pen, soldering iron.
- Direct-solder IP67 waterproof junction box.
Consumables
- Acetone; 80-grit & 120-grit sandpaper.
- Heavy-duty packing tape; Kapton tape (for frame insulation).
- Mixing buckets, stir sticks, squeegees, chip brushes.
- Butane/propane torch; drill and drill bits.
- Warm water, dish soap, Scotch-Brite pad.
Next: Phase 1 — Frame Prep & Bonding Surface.