Ford Mustang Glass Roof Panel - Fortunate Sun

With suitable masking in place, the perimeter of the roof panel is then scuffed. Why scuff the paint if the roof is being replaced? Because only a portion of the roof skin will be cut away. The scuffing will help the new glass roof panel bond to the remaining metal skin, as you'll soon see.

Measurements are then made to find and mark the precise longitudinal centerline of the roof panel. This step is critical in that placement of the roof cutting template is based off this centerline, as well as a specific distance back from the leading edge of the roof panel.

A template is then used to mark the outline of the roof-skin cutout. It's lined up to mark one side of the roof and then flipped over to do the other side.

Yes, that's an air chisel, but don't worry, Steve; it was only used to create the starter hole.

From broadsword to scalpel: A quiet and accurate electric metal shear was then used to cut out the perimeter of the opening.

Note two things here: First, the section of roof being lifted out is clearly floppy and flimsy because it's a single, unbraced piece of sheetmetal. All factory roof bracing and reinforcement is located outside the perimeter of the cutout. Second, note that the headliner is still in place at this point (you're looking at the substrate side, of course). It's purposely left in as long as possible to keep metal shavings out of the interior.

The pillar and cross trim pieces are affixed using 3M pressure-sensitive adhesive tape, the same stuff the OEMs use to bond trim at the factory.

The pillar trim goes on first. On each side, one piece spans from the base of the windshield to the top of the rear window, where a second piece continues on to the base of the C-pillar. Note how the roof portion sets into the gutter rail. This molded trim has a slightly textured, matte-black finish.

Adhesion promoter is used anywhere the PSA tape will bond to metal. This step may be overkill knowing how well the 3M tape works, but it's just another example of Classic Design's thorough approach.

Here, the piano-black windshield cross trim is bonded in place. A flange on this piece tucks between the rubber windshield trim and the leading edge of the roof sheetmetal.

After the rear cross trim has been temporarily set in place without bonding, the roof panel is test fit to be sure all is square; then the cross trim can be stuck in place. Note that the Glassback covers flanges on the cross and pillar trims for a finished appearance and a further guarantee that those trim pieces will stay put once the roof is bonded into place.

With all the trim in place, surface prep begins on the remaining roof surface and the underside of the Glassback panel. CDC specifies the use of Sika brand black primer preceded by a clear activator coat. These products are engineered to promote adhesion between the glass and metal.