Phase 1: Frame Prep & Bonding Surface

1. Weld the Frame

Weld the steel frame to 55” × 13½” with ½” outer measurements and the 13” cross-beams. Weld the two 13” flat steel cross-beams to the inside bottom of the frame, exactly 7” from each short end. Weld a third cross-beam in the center at 27½”.

  • Use clamps and a thin strip of hardboard at 13¼” as a jig to achieve a squared frame.
  • Measure corner-to-corner to verify square (~56½”).
Raw steel frame squared with clamps and hardboard jig.
Raw steel frame squared with clamps and hardboard jig.
  • Measure cross-bars and use welding magnets to hold them in place for welding.
Cross-bar measured and held with welding magnets.
Cross-bar measured and held with welding magnets.
Cross-bar tacked in place.
Cross-bar tacked in place.
  • Weld the cross-bars. The fourth one was the cleanest, but this was the first welding project so it was a learning experience.
Frame fully welded — first welding project.
Frame fully welded — first welding project.

2. Flatten the Frame

Welding warps steel. Place the frame on a perfectly flat table. If it rocks, use a hammer to gently tap it flat before continuing.

3. Prep the Metal

Use 80-grit sandpaper to heavily scuff the inside of the steel channel. Wipe it completely clean with acetone.

Frame interior sanded and wiped with acetone.
Frame interior sanded and wiped with acetone.

4. Prime the Metal

Spray the inside of the channel with epoxy metal primer. Let it cure fully (24 hours). Lightly scuff the primer with 120-grit sandpaper and wipe with acetone. This creates the perfect chemical bond for the Direct Bond method.

First epoxy primer coat.
First epoxy primer coat.
Second epoxy primer coat.
Second epoxy primer coat.
Primer fully cured and lightly scuffed.
Primer fully cured and lightly scuffed.

5. Test Fit

It is important to test the fit of the frame in the bed to make any additional corrections needed before casting in resin.

  • First test fit showed that the back of the channel was about 1/16” narrower than the back.
First test fit — back of the channel ~1/16" narrower.
First test fit — back of the channel ~1/16" narrower.
  • Using a grinder, reduce panels from 54 15/16” to 54 7/8” and retest fit.
Panels ground to 54 7/8" and re-fit.
Panels ground to 54 7/8" and re-fit.
  • Retest the full bed-length fit.
Full bed-length retest.
Full bed-length retest.
  • It may appear that the length is too long, but there is a gap between the end of the channel and the tailgate.
Gap between channel and tailgate.
Gap between channel and tailgate.
Closed-end bed-length fit.
Closed-end bed-length fit.
  • Finishing off with a full inspection of panel alignment and fit.
Final panel alignment and fit inspection.
Final panel alignment and fit inspection.

Next: Phase 2 — Bottom-Up Layup & Hole Drilling (in progress — progressing slowly, may not be complete until August 2026; may change based on actual experience).

Content licensed under CC0 1.0 — see LICENSE.