Building a fiberglass top

Car 1254, a 1978 the subject of this project. I decided that I needed windows, which led to the need for a fiberglass top. I will record my experiences and problems as I go -- so the outcome of this project is unclear at present. It could well end up in the trash can. I hope that you can benefit from this effort. If you have questions or suggestions, please contact me at

Car 689, a 1973 Phaeton was my second attempt in 2011. I was not pleased with the look of the first top (at the bottom of this page) but the windows worked as I wanted them to. On the older Glassic, I wanted a more authentic look but did not care about the windows. Car 689's top project appears HERE


I picked up this topper from a junk yard ($20) - I don't know what it came from, and it was cheap because it was dented in on top. I had hoped that it would pop back up. It did not and will have to have bracing inside. The glass, although darker than I would like, looks useful, (see obstacles below) and I am hoping that cutting it will not cost too much.

I decided to put the back of the cap as the front and cut the length after careful measurement. The plan is to use the back of the top (left front corner of the picture) as the main back piece of the back of the new top. In other words, tip the piece on the left toward you, and then I can cut a window hole later. The piece is wider than the car, so a lot of cut and splice will be needed.

The back of this new top is too wide, so I plan to cut a vee on each side of the top and bring it narrower. That Vee would likely reach forward to the back of the front door. It looks like the 90 inch length of that topper will barely make enough for the top, front to back AND the upright back piece. In this pic, there is a 2x4 resting on the windshield frame to hold the front up (I will build a filler strip later) and the back is propped up with a stack of wood pieces to check for height.

Observations at this early stage:

This top is going to be heavier than I thought. That means problems moving it about while building it, and problems pulling it off for open driving.

The topper has an inner liner of fabric glued on -- this will be a problem when splicing. The top also consists of two layers with loose pieces of corrugated cardboard in between. That carboard is moving around, and the two layers will also make problems with splicing.

The back curves both around the back seat, as well as up and down (the back is highest in the center and goes downhill as you go left or right-- getting the rear section to rest evenly on the car will not be simple.

Obstacles -- Well, lesson one. One does NOT cut tempered glass. All of that beautiful tinted glass - to the trash bin. I will have to have flat side glass made and tempered. $6 per square foot is my first estimate, with extra charges for rounded corners, holes etc.

The hunk of aluminum used in each corner to make the receiver for the windshield stanchion pokey things (my technical term) -- that size aluminum stock (1" x 2" x 2") is NOT available at our huge aluminum store. The only thing I saw in my first visit there was a hunk 4 x 4 x 8. I did not price it, nor do I relish cutting it down. Perhaps steel, although tapping and drilling steel is a bit less fun.

Here is a cardboard cutout of the rear ledge of the car, with a hole cut out for the seat back to pop through. The topper is laying face up on the ground with the part that fits against the back window of the truck facing up. After this, I cut the top in half, to start to make it narrower, then cut notches in the curved part on top to start to bend it narrower.

These are the piece cut for the back. As of 4/9/02 the project is on hold while I get a new rebuilt engine for my car. It blew up its last "rebuild engine". The wire is to bend the pieces at more of a 90 degree angle. I have a frame that will rest all around the back half, and the fiberglass will be bolted to it. The frame needs some adjusting for fit, and that is when the engine blew, so I can't get back for that part.

Here are the pieces from the outside. They are hanging over on the side, but will be bolted to the frame and the whole thing will sit upright. I am thinking of an oval window, since, by the time I add a brace top and bottom to hold the two halves together, there wont be room for an original size window. Too bad, because we need all the rear view we can spare. Obviously, the trick would be to get a top of about the right width in the first place so the splicing would not be necessary. Stay tuned.

With all of the scratching and splicing, I am now considering having the whole thing vinyl covered when (or IF I get it done.)

here is the "frame" on which to mount the back fiberglass. This frame will bolt to the car body. This is made out of 1 inch wide aluminum and cost about $110 from the welder.

another view of the contraption. The angled material at the side, and the upright will form the frame for the rear windows, which, I guess will be plastic, and non-removable. I am hoping that the rear window will flip up so that air can pass through when the front windows are removed.

Here is a trial fit to see if it all reaches. The two halves of the rear have been spliced and hooked on to the frame, and the top laid on top to be sure it is long enough.

Obviously a big issue is how to narrow the top in the rear so that it lines up with the rear panel. Note the corrugated carboard sandwiched between the two layers on the top part.

The visor is sitting up high rather than covering over the windshield. I left it high to provide as much headroom as possible. As it is, at 5' 10" and the seat leaning back a bit (to provide room for my gut) I end up with about two inches of headroom. A planned sunroof may steal a little of THAT space.

Side view. Imagine it in white Vinyl. I am leaning more and more to the vinyl to cover up all of the screws that are holding this together. Filling nicely for paint sounds like a bit too much work. Also, vinyl will simulate a soft top, excusing any little ripples and bumps etc.

Here is where I popped the hole in the back for the window. The shiny dots are countersunk screws going through the fiberglass and into a 3/4 inch plywood frame on the inside.

Here is the interior view The plywood looks like a perfect match with the fuzzy interior, but it is just flat black paint. I have a piece of plastic (thick) that I got at a yard sale. I will screw that on with 4 or 6 screws that can be removed for fresh air exit out the back. I really want to hinge the window at the top so it will self-store when open.

More to come!

Well, I have gone and done it. I got so wound up that I didn't take as manyh pictures as I should have. This picture has that gray background because it was in front of the woods and you could not see the top at all, so I touched it up.

Attaching the back part to the car: I drilled a couple of holes in ledge around the back of the car. The fiberglass was VERY thick there. I wanted the finish to be holes in the car rather than bolts popping up, so that when the top was set down on the car, it would not have to come straight down onto the car. What I did, which seems to work was: I got a threaded receptical at Home Depot (it has a lip and you are supposed to hammer it into a wood surface so you can attach a bolt) -- I hammered it into a scrap of wood (like a 1x2x3") and then I glued on a scrap of aluminum with a hole in it to the TOP. You see, the pressure would be for the top to lift UP, so it would TEND to want to pull the threads back up out of the scrap of wood.

Then, I took a long, threaded rod (3'), lowered it though the hole on the deck, attached my sandwich of aluminum, and wood and threaded receiver to the bottom -- I gobbed on some fiberglass bondo, and lifted up on the rod to bring it up on the underside of the lip. I held it in place and Ta da! I unthreaded the long rod and there, down in the hole were the threads. I believe I used 5/16 bolts then to hold the top on. It seems to work great at highway speeds.

Right now, there is a LOT of finishing work to do. I received two different estimates of $500 to vinyl cover the whole thing. I am considering other options!

More to follow.

Here is the top showing splices and bondo. It is hanging on the chains with a 2 x 2 cross brace. Angelique is watching from a safe distance.

Here is the look in white. I used white primer to hold me until I have money for vinyl. I still have not done anything about windows, which is what started all of this. The rear will be easy, just plop in some plastic. As for the front, I am still figuring what will work best.

another view of the top.

Looking down on the sunroof. This came from a pull-your-own junkyard $25.00.
It came from a 1986 Dodge Aries K.
This very neat addition is the highlight of the project..

The last step was to get the project covered in vinyl. I had gotten THREE estimates of exactly $500 for the project. By the time I had saved up the money, the cheapest estimate turned out to be $650. (which included padding the top) With that estimate, I had to buy the edging to go around the window areas. That was found in a BOAT SUPPLY STORE - They had white or black in various widths to handle different thicknesses of material that was being edged. The roll of edging cost about $25.

For pictures of the car with the project finished see Car 1254.

If you are still reading here, try looking at the WINDOWS that I built to go with this.
They could even work with a convertible top.