October 2012
Blog | December 2012 | July 2012

Fiberglass Trunk Lid

07/10/12 13:16 Filed in: Auto
This article describes the fitting of a fiberglass trunk lid on a 1937 Chevy Coupe.  The trunk lid was purchased from Superior Glassworks in Mulino, OR in August 2011.  The described installation was completed in August 2012.
See http://www.superiorglassworks.com/Trunk-Lid-for-1937-1938-Chevrolet-Coupe-p/3806.htm
trunk lid catalog
The trunk lid was actually delivered in two pieces, an inner piece that is ribbed and the outer piece that had been frenched to hold the license plate.  Note that the outer lid currently shown above is without the frenched-in license.
trunk lid inner
The first step in installation was to mark the inner lid for the hinge bolt. The inner lid was positioned using cardboard along the edges and clamps to hold it in place while the hinge holes were marked with pencil from the underside.
trunk lid clamped to mark hinges - 2
The holes were then drilled and tapped through the metal reinforcement plates bonded into the inner lid.
trunk lid drilled holes
The inner lid was then bolted into place and the outer lid was positioned on it for initial checking.  It was confirmed at this point that some modification was going to be needed to the hinges to get the surfaces of the lid and body be level.  Adjustment will be handled later.
trunk lid initial fitting
The next step was to drill holes for the latch mechanism and to cut the inner lid to clear the frenched inset for the license plate.  Initially, a section was just cut out to clear the license plate area.  This section was later refined to actually fit the contour of the frenched surface.
trunk lid cut to clear license
Since the contour of the inner trunk lid was raised more in the top middle due to some warpage in the mold process, a few saw cuts were made in the top edge and the lid was clamped and glassed to lock the reduced contour in place.
trunk lid cut to adjust contour
The latch mechanism was then mounted by drilling holes where needed and the nuts for the mointing bolts were glassed over on the inner side to hold them in place.  These areas would be inaccessible after the two lid pieces were bonded together so this allows the latch bolts to be removed if later necessary.
trunk lid latch bolt nuts glassed
After sanding down the contact areas of the two lids pieces, they were bonded together with polyurethane construction adhesive and then clamped together at eight points for 24 hours.
trunk lid adhesive trunk lid clamped
Following the bonding of the two lid pieces, the piece cut out of the inner lid was modified to closely fit the frenched-in license area and then glassed together with both lid pieces.
trunk lid french glassed
Note that this could have been done much cleaner if the portion removed from the inner lid could have been determined without cutting out the whole section first.  The total material that was eventually removed looked like this.
trunk lid french cutout trunk lid french cutout2
After all of the above was done, the extra glue was removed from the seam and the edges were sanded down so the the joint was even all around.  The original trunk lift supports were replaced with a pressurized gas lift kit.  Now it actually takes as much downward force to close the lid as it did originally to open it.
trunk lid gas lift kit
Finally, the hinges were adjusted for position by using two orange strap clamps to pull the lid to the left and up while wedges were inserted to lower the surface to align with the body.  These wedges are currently made of wood but may be replaced with metal later.
 
trunk lid hinge adjustment trunk lid hinge wedge
The final trunk lid looks like this before further body work and painting is done in the future. Note that the left taillight stand is not crooked.  It's just a result of the camera lens.  The stand will be modified to remove the vertical taillight bracket. The ferrule that was originally used around the trunk handle could not be used. The shaft of the handle would not reach through to the latch mechanism since the new fiberglass lid is at least 1/4 inch thicker than the original steel lid.
trunk lid w collectors plate
 

Tags: