Tricks Of The Trade

This is a relatively easy top to install. We have provided a very detailed step by step procedure in the following two pages of text and graphics to guide the reader. In doing so we also encountered some real life rust and worn parts that had to be resolved as well. We also included our tricks learned as a result of replacing many tops since the early 70's. We hope the reader is not overwelmed and discouraged by the excessive detail provided. Unfortunately these tops get tougher to install as the cars further age and the need for quality workmanship increases with the increasing value of the cars. Unfortunately not all tops are created equal. We have always carried only the best quality tops. We have to face our customers after the installation and live with our mail order customers hopefully for a very long time.

Special tools needed: You'll need regular pliers, needle nose pliers, punch, single edged razor blade, screw drivers, small wrenches, and strong hands. 

Begin by first removing the wire-on molding just above the rear window. This molding covers a seam which is present on most convertible tops. The wire-on molding is folded front to back. First remove the stainless ends usually fastened by phillips screws (ill. 1). Unfold the wire-on molding and remove the staples securing it to the top bow. This is done using a sharp punch to pry up. Usually 1/2 of the staple separates from the bow. Use pliers, either regular or needle nose to finish the staple removal. Remove all the staples securing the top seam overlap after the molding has been removed.

Remove the rear weatherstrip by first finding and removing the weatherstrip retainer wire embedded within the weatherstrip (ill. 2). The weatherstrip will easily pull off once the retainer wire is removed (ill. 3). The top fabric is fastened to the rear bow by a small welt or beading stiched into the fabric edge and tucked into a groove in the bow. Use a screw driver to untuck the top fabric from the rear bow (ill. 2).

Remove all front weatherstrip which include front center, left and right corners. The center weatherstrip is secured by plastic push in studs embedded into the weatherstrip and spaced approximately six inches apart. Much care should be taken when desecuring the plastic studs from the bow (ill.5). The studs are t-shaped therefore pry them loose with a screw driver placed next to the stud. The corner weatherstrips are secured by two metal push in clips, one plastic push in clip, one phillips screw, and one threaded embedded steel stud. Pry the clips loose in the same manner used when removing the center weather plastic studs (ill. 4). Unscrew the screw and remove the one nut on the back side of the side rail.

Remove the front fabric molding staples, then the top fabric wrap around staples(ill.5). The top is then fastened only by the side verticle weatherstrip studs. The quick way to remove the side vertical weatherstrip is done using a single edge razor blade to slice the top material facilitating easy access to the weatherstrip stud nuts (ill.6). There are three nuts and washers that need to be removed. The old top is then removed exposing the top pads (ill.7). The top pads and adjacent straps are replaced one at a time so as not to disturb existing top bow alignment. Before changing pads and straps we must repair the existing front bow rot. We were very surprised to find the extent of rust on the front bow as we did on this particular Corvette. In fact the entire frame of the car was in much better condition. The only explanation we could surmize was that the top had been replaced once before many years ago and the fabric wrapped around the front bow had been trimmed short, exposing a surface that we find typically covered by fabric. Since the rust was isolated we weighed the cost factors involved in replacing the front bow as compared with its repair. A new bow cost approximately $300.00 and requires three or four hours for installation since their fit is not as good as one might expect. We estimated six to eight hours to repair the existing bow not unlike the many we had repaired over the years prior to this replacement part's availability. The repair would result in a substantial savings for the customer when considering our shop rate and no delay in progress .

Repair rusted front front bow by first grinding the rusted surface (ill. 7). The pitted areas are then ground using a die grinder (ill. 8). This process is similar to a dentist preparing a tooth for a filling. Sheet metal plates approximately .020 to .030 inch thick are then fabricated and fitted over the rotted areas (ill. 8). The repair plates are then mig welded in place (ill. 9). The welds are then ground flat and the entire repair area is also lightly ground in preparation for body filler application. Apply a light coat of body filler. Trim or cheese grade when half hard. Sand and shape the body filler as needed when completely cured (ill. 9).

Install front tack strip: The original tack strip, (what the top fabric staples are secured to), usually survive. This is one of those rare times that require its replacement. Oddly enough the original tack strip from this car was in excellent shape but we opted to replace it with a wooden replacement. The factory tack strip and the aftermarket reproduction are made from a fiber board, paper-like material. We have found that a soft wood replacement holds the staples better and will probably out live its original counter part. We discovered this process many years ago when no replacement part was available. The wood we use is from a yard stick which used to be given away free from most hardware store and lumber yards (ill. 10). The yard stick is cut approximately 5/8 inch wide and a number of pieces are cut to eight to ten inch lengths. The pieces are fitted and trimmed as necessary. When satisfied with the overall fit they are bonded into place using body filler. The factory tabs are then rebent over the new tack strip (ill. 10). The entire header bar is then primed and painted gloss black lacquer.

Check the dimensions and fit and orientation of the old pads and straps before commiting to their replacement.We have found that old pads and straps shrink a bit with age. It is not necessary to use a tape measure extensively for this procedure, rather a prefit of the new top will best determine if any change in pad length is necessary. The critical item is the location of the rear tack strip bow, (where the wire-on molding was previously secured). There is a chance that this bow crept forward slightly with the aging pads. Install the new top with the rear edge wrapped around the rear bow, which clamps to the car. Pull the material to the front bow and around the side vertical rails. The open seam of the new top should be locating exactly over the rear tack strip bow. A close inspection of the ends, left and right, will show that this seam is comprised of two 1/2 inch wide flaps that overlap each other. The point where they overlap will be stapled to the rear tack strip so the staple point should locate precisely over the middle of the tack strip (ill. 18). You will need to pull back on the rear tack strip bow while pulling forward on the new top material to accurately check this fit. 
      Also note the pad orientation over the side glass (ill. 11). Did the pads show in this area before the old top was removed? No part of the pad should appear lower than the bottom surface of the side rail. Did the side glass fit its mating weatherstrip before the old top was removed? The original factory fit in this regard was precise. Now would be a good time to check and tweak this configuration. Better yet, if the car has a hard top fit the side glass to the hard top and realign soft top bows to that configuration making both tops a perfect fit as the factory did when the car was new. 
      The straps almost always need to be installed allowing an increase of about 1/8 inch longer distance between the tack strip bow and the lower bow.
      If you feel a need to alter the location of the rear tack strip bow from its present location as dictated by locating the overlap seam you should not encounter a deviation larger than 1/4 inch unless a botched up home made top had been previously installed.
      As the top frame ages many pivoting points wear. Typically the rear bow tends to inch forward. Two things have occurred; The small connecting "S" shaped bracket has bent forward from many years of supporting tight fabric and some wear has developed in its attaching pivot rivet. A quick rebending of the "S" bracket (ill. 11) will usually resolve the problem adequately.

Begin installing one new pad first. Check the distance between the tack strip bow and the rear bow on the other side for reference (ill. 12). Remove all staples. You will find that the generally practiced rule with pad fastening does not render staples on a surface adjacent to the top material. The new pad is placed with the rear tack bow properly placed and properly aligned over the side rail with no pad material appearing below the side rail bottom surface. Remove the inside padding material before stapling into place. The pad is then stapled first at the front bow, then rear tack bow and then the middle (ill. 13). Install the padding and properly place the outer pad covers as illustrated (ill. 13). Apply adhesive to the two surfaces that will meet each other. Allow adhesive to dry before joining. The overlapped seams are then taped. Apply adhesive to the area that will be taped then apply the tape. 

Install the top straps using a punch to locate holes in the rear bow (ill. 14). Check the distance measurement reference taken from the opposite side. The strap is stapled to the rear tack strip bow under the pad (ill. 14). With the front clamped and the rear latched two notches the straps and pads should appear taught leaving approximately 1/2 inch clearance under the rear bow between it and the body.

This Article is Continued . . . .

1. Remove rear wire-on molding & staples

2. Remove w/strip retainer, w/strip, & top

3. Removing the rear weatherstrip

4. Remove front corner w/strip screws & clips

5. Remove front w/strip & factory staples

6. Using a single edge razor slit top & remove w/strip

7. Stripped down to the pads & begin rust repair

8.  Grind out the divitte & position new sheet metal 

9. Mig weld & apply body filler

10. Install wooden tack strip & paint header

11. Align rear bow & check pad & glass alignment

12. Remove pad staples & measure other side

13. Install pad foam & glue outer seam overlap

14. Pad seam is then tapped & Install straps

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