Wednesday, January 25, 2012

Building A Fiberglass Trunk Lid (part 1)

This body did not come with any type of trunk lid or filler piece for the trunk.  At first I was going to make a mold off the body and then pull a piece from the mold and complete a trunk.  After looking at how much it would cost for the fiberglass, resin, bondo,sandpaper, time etc.  and knowing that I would probably never need the mold again, I decided to just make one from fiberglass and finish it on the car.  Doing it this way makes the deck lid a little heavier but saves a lot of time and money.  I could make one out of sheet metal, but I wanted to keep the entire car fiberglass.  I started by taking a piece of 22 ga. sheet metal and rough bent it over an oxygen bottle to get a basis curve to fit the body.  Then I bent a long strip at 90 degrees and pop riveted it to the top or forward edge so that it would sit on the edge of the body. Next I used several sheet rock (sheet metal) screws and screwed it along the edge and bottom to suck the metal close to the body contour. Next I covered the sheet metal with wax paper , taped it down and then applied 4 layers of 1 oz  fiberglass mat ( not shown).  This then forms the basis for the trunk and the rest of the process.

Now comes the fun part.  I made a pattern of the contour of the body and transferred it to a 2 x 4 and rounded the edges of the contour on both sides,  This will make 2 lefts and 2 right sides to form the inside lip of both the trunk and the body.  Cover the  2 x 4 with wax paper so that it fits tight and nice, tape it down good and use  some mold release or car paste wax.  Cover with three or four layers of 1 oz fiberglass mat.  Make two off one side and then reverse and make two off of the opposite side.

I also need a nice straight one for the front or top of the trunk lid.  Use a nice straight 2 x 4 , cover with wax paper and apply 3 or 4 layers of 1 oz. fiberglass mat.

This picture shows all five fiberglass pieces along with the 2 x 4 I used to make the side pieces.

Trim the pieces with a band saw or jig saw leaving at least an inch on both sides.  Do this with all five pieces.  Use some lacquer thinner to clean up any mold release or wax residue.  Take some 36 or 40 grit sand paper and rough up the outside surfaces to help insure a better bond and grip for the fiberglass bondo.

Now its time to put these pieces in place.  Take some 36 or 40 grit sandpaper and rough up the inner surfaces of the body and the inner surface of the trunk.  Mix up some fiberglass bondo and spread it along the surface to be bonded (mated).  I pre drilled two 1/4 inch holes and pre fitted each piece so that when the installation takes place,  the bolts will hold the pieces in place until cured.  When cured (kicked) remove the bolts, fill the hole and dress up /off any excess.  Fill in low spots rough sand and get ready for the next step in part 2.

Current Project:1927 Highboy - The hard way!