How to Restore Door Panel & Glass in Muscle Cars

One method of addressing door panel restoration is, of course, to chuck the door panels altogether— saves weight, sure does, and it’s worth another tenth in the quarter— and to use a pair of Vise-Grips in lieu of actual window crank handles. But we really should use those Vise-Grips for something a little more productive than rolling up windows.

 


This Tech Tip is From the Full Book, MUSCLE CAR INTERIOR RESTORATION GUIDE. For a comprehensive guide on this entire subject you can visit this link:
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Perhaps that’s a little extreme. But in the great scheme of things, door panels—and the stuff they hide inside your doors—tend to be ignored until and unless something goes wrong with them: The window doesn’t roll up smoothly, or your key snaps off in the door lock.

Granted, door panels tend not to suffer as much abuse or wear and tear as seat covers and carpet. They occupy a low-touch, low-function position. Yet they still gather dust, they still fade in the sun, and they do suffer whenever you happen to forget to roll up your windows before a thunderstorm passes through.

 

Though door panels are built to withstand abuse and wear, water damage or the occasional tear can warrant replacing them. Many times they simply come up missing in a project car. Fortunately, the aftermarket has a wide range of reproduction door panels with the correct dielectrically stamped patterns.

Though door panels are built to withstand abuse and wear, water damage or the occasional tear can warrant replacing them. Many times they simply come up missing in a project car. Fortunately, the aftermarket has a wide range of reproduction door panels with the correct dielectrically stamped patterns.

 

Fortunately, door panels are some of the simplest parts of your interior to replace, as long as the aftermarket has smiled kindly on your chosen make and model of muscle car (or as long as you’ve found NOS replacements). Unless you’re double-jointed and have arms as thin as a little girl, however, all the mechanisms and the glass behind the door panels, are a little trickier, but not impossible, to restore and maintain. So I’m going to give you a look inside those panels and provide instructions on how to address some common door and glass maladies.

Door Panel Replacement

Our 1968 Camaro from Chapter 5 had door panels that remained in rather decent condition, save for the mildew all over the door and interior panels. While we could have cleaned the mildew away, we discovered that the door panels had some water damage, hidden from normal view, so we opted to find some reproduction panels sans living organisms.

As with every remove-andreplace procedure, we first checked that the reproductions, ordered from Classic Industries, matched the originals in every detail. While street rod upholsterers create custom door panels all the time, often from scratch, it’s difficult to match the exact detail of original muscle car door panels without a process called dielectric stamping, which bonds dissimilar materials together under vacuum and with a high amount of detail.

New door panels usually come in one of two levels of finish: assembled or unassembled. Despite the implication in their name, unassembled door panels usually come mostly complete, lacking only some trim items that can easily be transferred and the metal top section of the panel.

Every now and then, depending on the car, a reproduction door panel skin will come separate from its backing board. In that case, it is simple enough to line up the new panel with the new backing board, glue the two together with spray adhesive, and then trim to fit. For most guys who work on projects in their home garages, the preferred option is the assembled panel. But even assembled panels don’t include everything, as we’ll see momentarily.

We started the replacement process by removing the armrest, which is screwed to the door through the door panel. We next removed the door latch handle and the window crank handle, for which we used a special tool available in just about any auto parts store in the country, even those big-box chain stores. We’ve found that the clip holding in the crank handle is always between the handle itself and the trim ring, and that it’s usually inserted from the back of the car at the factory (the easiest, and thus most efficient installation procedure), so we approached the clip from the front of the car to back it out. Rather than shooting the clip across the shop, we carefully left the clip in position on the window crank to make reassembly simpler. We then slid the crank off its splines and removed the door lock knobs.

Door Panel Replacement

Step-1: Door Panel Replacement

1On our 1968 Camaro, the door panels looked as if they could use just a simple cleaning. However, we suspected the real damage lay beneath the surface, so we ordered reproduction panels and began removing the old, moldy panels. Removal starts by unscrewing the armrest.

 

 

 

Step-2: Door Panel Replacement

2Using this special tool, we were able to get behind the window crank’s base to remove the clip that secures the crank to its post. Note the protective plastic disc; you’ll need to slide the tool between the disc and the base of the crank to access the clip.

 

 

 

 

Step-3: Door Panel Replacement

3Here you can see the back side of the window crank handle’s base and the spring clip that keeps the handle in place. You can also see how the tool pushes the clip away from the window crank post, allowing the handle to be removed from the post. Try to keep the clip with the window crank handle.

 

 

 

 

Step-4: Door Panel Replacement

4Under the door panel is the vapor barrier, which the factory affixed to the inner door structure with dum-dum. If your vapor barrier is missing or damaged, you can replace it with tar paper or house wrap. Our Camaro’s vapor barrier remained in good condition, so we decided to reuse it.

 

 

Step-5: Door Panel Replacement

5The spring clips are usually inserted into the pressboard backing of the door panel, which is one reason you don’t want to yank the clips away from the door, especially if you’re planning on reusing the door panel. Note the pressboard has started to tear around the top spring clip, illustrating how easy it is to damage the pressboard.

 

 

 

 

Step-6: Door Panel Replacement

6Our new door panel did not come with the Camaro nameplate preinstalled, so we had to transfer it over from the old panel. We gently pried the clips from the nameplate’s three studs. Because the nameplates were usually cast from pot metal, the tiny studs can be very brittle and easy to snap off.

 

 

 

Step-7: Door Panel Replacement

7With the nameplate removed from the old panel, we centered it in its location on the new panel and firmly pressed down to allow the three studs to create three indentations in the exact locations where we needed to punch holes for the studs.

 

 

 

Step-8: Door Panel Replacement

8Using a sharp awl, we punched out the three holes. We pressed down only until we felt the awl punch through the pressboard backing of the door panel.

 

 

 

 

 

Step-9: Door Panel Replacement

9Because the nameplate studs were rather short, the back side of the door panel (where we punched the holes) needed to be perfectly smooth. Even the small amount of material punched through would not leave enough stud length for the clips, so we trimmed the pressboard flush with a razor blade.

 

 

 

Step-10: Door Panel Replacement

10Next, we affixed the nameplate to the door panel and carefully pressed the nuts back onto the studs. Note the center stud, which only protrudes from the pressboard by a couple centimeters.

 

 

 

 

 

 

 

 

 

 

Step-11: Door Panel Replacement

11We also transferred the spring clips from their pockets in the old door panel to the pre-punched pockets in the new one, noting their correct alignment. Reinstallation of the door panel starts by hooking the window fuzzy strip over the window channel, then pushing in the spring clips from top to bottom.

 

 

 

 

Step-12: Door Panel Replacement

12The posts for the window crank and the latch handle are usually not punched on reproduction panels. As you push the spring clips into the door, the posts will push out against the vinyl skin of the door panel, showing you where you need to cut with a razor blade to allow the posts to poke through.

 

 

 

Step-13: Door Panel Replacement

13With our posts located and those holes punched, we removed the new panel, taped down the vapor barrier, and popped on the spring that holds tension on the window crank handle. Now would be a good time to replace any cracked or damaged weather stripping.

 

 

 

 

Step-14: Door Panel Replacement

14With the vapor barrier in place, we installed the door panel once again, affixed the latch handle, and screwed the armrest back on. To reinstall the window crank handle, we placed the spring clip on the handle itself. Once we slid the protective plastic disc and the crank handle back over the crank post, we were able to push the clip into place.

 

 

 

Step-15: Door Panel Replacement

15Finally, a line of screws secures the bottom edge of the new door panel, and a new lock knob on top finishes off the installation. If you have all of your supplies ready and don’t shoot any clips across the garage, prompting a three-hour search for one tiny piece of metal, you should be able to complete both door panel replacements in about 1 hour.

 

 

 

After removing a couple screws from the bottom of the door panel— your muscle car’s door panel may have as few as none or as many as six screws—we then slipped a pry tool behind the door panel and slowly worked it around the perimeter of the panel to remove the metal clips holding the panel on. We removed these clips one by one, taking care not to tear them away from the cardboardlike backing panel, which usually becomes weak over time and with exposure to moisture. Fortunately, metal clips of some sort, which are reusable in new door panels, were employed through the 1980s, until the factories started to replace them with one-time-use plastic clips.

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At this point, we unhooked the door panel from the inside window channel at the top of the door and set the panel aside. If your car has power windows or locks, it may be necessary to unplug the wiring harness from the switch panels after separating the panel from the door, but before totally removing the panel. Behind the panel is what is called the vapor barrier—essentially a piece of tar paper that covers the openings stamped into the inner door. The vapor barrier is held on with dumdum, which usually remains pliable and sticky enough after all these years. Finally, behind that and around the window crank post, is a coil spring used to keep tension on the window crank handle.

With the door panels off, it is a good time to check the insides of the doors for rust or anything that might cause rust. This may be the only time in your ownership of the car—or even in your car’s lifetime— that the door panels come off and afford you the opportunity for such an inspection. You’ll be amazed at what can accumulate there, especially if your window sweeps are broken or missing. Dirt, dust, mouse nests, and other debris are prime examples, so poke your shop-vac in there and suck out all you can. Also check your drain plugs and/or weep holes. The people who designed your car figured out methods to evacuate the water that inevitably enters your doors, and without those methods, you’re sure to see rust in the bottoms of your doors. Some of the debris may have become caked on to the interior surfaces of your doors, so reach in with a wire brush or a paint scraper and knock off the caked-on debris.

Also while rooting around inside your doors, take a moment to grease everything that moves, including door lock mechanisms, latch mechanisms, and window mechanisms. Removing the interior panels—we’ll discuss that in a moment—allows similar opportunities for inspection, cleaning, and lubing. With both apart, now would be a good time to inspect and, if necessary, replace your side windows (which you can read more about later in this chapter).

The new door panel came assembled, but did not include the rectangular Camaro emblem situated above the armrest. Reproduction emblems are available, but the original emblem on the old door panel remained in decent shape, so we decided to transfer the emblem from the old door panel to the new one.

The most difficult part of transferring the emblem was removing the tiny clips from the tinier pot metal posts that secured the emblem to the door panel. With a pair of pliers, we gently wiggled the clips back and forth until they separated from the posts. We then positioned the emblem over the new door panel and pushed down to make three indentations in the panel exactly where we wanted the posts to poke through the panel. Next, we used an awl to open up those holes, then used a razor blade to shave off the material punched through the holes by the awl. The excess material that’s punched through sometimes makes the cardboard too thick for the clips to attach to the posts of the emblem. Reinstalling the clips on the posts also requires a gentle touch to avoid snapping the posts from the emblem.

In the case of a car equipped with power windows or power locks, the reproduction door panel should have punchouts in the pressed cardboard backing for the switches in their proper locations. Go ahead and punch those out, then cut an X in the vinyl from the back side. With a bit of spray adhesive, you can fold the resulting flaps back over the cardboard backing and then transfer the switches and bezels from the old door panel to the new door panel.

The new door panel also did not come with the metal clips that hold the sides of the panel to the door, so we had to transfer those before popping the new panel to the door. Before removing the clips from the old panel, however, we noted their orientation—clipped up or clipped down. If we were to orient the clips improperly, then the clips would not line up with the door.

Installation, as is often the case, is the reverse of disassembly. If you are replacing the vapor barrier, do it now, making sure to keep the spring on the window crank post. Hang the top of the panel over the rod for the door lock, then make sure all the clips are aligned with their holes in the door. If the new panel doesn’t include holes for the window crank and door latch handle posts, make sure the panel is aligned perfectly with the door before using a razor blade to cut out the holes for the posts—by pressing the blade of the razor against the posts (through the panel) in an X pattern. The holes for the armrest’s screws may also need to be cut, so hold the armrest up to the panel to judge where the holes need to go and use either an awl or a razor blade to punch those holes.

Give the clips around the perimeter of the panel a good pop, and screw down the bottom of the panel. The window crank handle, still with its clip loaded, can now slip over the splines of its post. Either the clip removal tool or a good whack on the handle will seat the clip into its locked position. With the door latch handle and the armrest reinstalled, the installation of the new door panel is complete.

Interior Panel Reskinning

Most reproduction door panels come in a kit that includes the materials to refresh the interior panels also, those panels to either side of the rear seat. You wouldn’t want to have those sticking out like a sore thumb against a fresh, new door panel. And if your interior panels are held in with clips, as the door panels are, then you should be good to go—just repeat the door panel installation process.

This Camaro uses stamped sheetmetal to form the interior panels. It also uses a vinyl skin—similar to the door panel’s skin—to cover the sheetmetal with a thin layer of cotton or foam between for padding in certain places, most notably the integrated armrest. Removing the panels from the car is as simple as removing a handful of screws, normally hidden by the rear seat.

Step-1: Interior Panel Reskinning

1Moving to the rear interior panels, this Camaro convertible used three different pieces to make up the entire interior panel section. Reproduction skins for two of the pieces and a new dielectrically stamped panel for the third piece mean we don’t have to bother de-fungus-ifying the panels.

 

 

 

Step-2: Interior Panel Reskinning

2After removing the screws that secure the lower two pieces, we were able to set them aside and access the convertible top’s springs and hydraulics. We removed the rear window crank handle using the same exact process as we used for the front window crank handle.

 

 

 

 

Step-3: Interior Panel Reskinning

3We were able to simply lift the ashtrays out of their holes in the armrests. Most ashtrays are designed to be lifted out so their contents can be swiftly emptied. A bit of chrome polish will clean up the ashtrays and have them looking like new.

 

 

 

 

 

 

 

 

Step-4: Interior Panel Reskinning

4With the lower two pieces out of the car, we can strip off the old vinyl skins. The pieces are quite simply constructed of a stamped section of sheetmetal with the skins glued to them, and with the occasional piece of cotton or jute padding on the armrest surfaces.

 

 

 

 

 

 

 

Step-5: Interior Panel Reskinning

5Once we’ve stripped the old vinyl skins from their sheetmetal cores, we can lay out the new skins and spray both the back side of the skins and the cores with contact adhesive.

 

 

 

 

Step-6: Interior Panel Reskinning

6Using the seams of the skins as a guide and starting point, we stretched the vinyl over the sheetmetal cores, working our way outward toward the edges in incremental steps. Once we reached the edges, we sprayed the overlaps with contact adhesive, then folded them over to the back sides of the cores.

 

 

 

 

Step-7: Interior Panel Reskinning

7The upper stamped panel hooks over the window channel as did the door panel, and is trimmed for the window crank post the same way. The two lower pieces screw into their respective locations.

 

 

 

 

 

 

 

 

 

Step-8: Interior Panel Reskinning

8The sides of the stamped panel, however, are not held in with clips. Instead, they are left loose and wrap around the sheetmetal stampings of the door opening. To keep from smearing contact adhesive all over the place, we brushed it into this area rather than spraying it.

 

 

 

 

 

 

With the panels on the workbench, and after removing the ashtrays or other trim, the old vinyl can easily be stripped from the sheetmetal by pulling at a loose edge. While removing the vinyl from the sheetmetal, note how they fit to one another. On this Camaro, for example, a stitched seam between two pieces of vinyl marked the edge of the armrest section of the panel.

Also note where the panel was originally glued. It’s usually not necessary to bond the back of the vinyl skin to the thin cotton layer, so you should spray adhesive only on the sections where the vinyl meets the bare metal. With both the vinyl and the metal sprayed with adhesive, it’s then just a matter of stretching the vinyl over the metal and folding the edges over, darting where necessary. Start stretching by matching the centers of the vinyl skin and the metal frame, or by matching a hard reference point like a stitched seam, then work toward the edges of the metal frame, using clamps where necessary. The new skin likely will not have holes for the ashtrays or other trim cut out, so do that now, cutting any necessary holes from the back side of the panel.

Hard Plastics Restoration

But the above discussion doesn’t address the use of the hard plastics that became increasingly common in muscle car interiors right around 1970, especially in Mopars. You know the type—molded ABS with a shallow grainy texture, prone to cracking and not as easily reproduced as dielectric soft vinyl panels.

If you go back to the discussion of vinyls used in dashboards in Chapter 2, you’ll see how UV exposure, along with the steady progression of time, degrades the hard plastics used in trim, consoles, package trays, and even in entire door panels, causing them to become brittle. They weren’t very strong to begin with, so a careless move here or a bit of storage rash there can easily snap a hard plastic piece in two or cause a significant crack. I’ve even occasionally seen hard plastic pieces that were placed too close to light bulbs melt from the heat given off by the bulbs.

Most people turn to replacement first, which is understandable as long as you can locate an intact NOS, used, or reproduction piece. If that’s not the case, or if you would rather save a few bucks, it has become rather simple to repair the piece yourself. And depending on the specifics of the piece, you can choose from a couple different methods of repair: plastic welding or Plastex’s plastic repair kit.

Plastic Welding

Step-1: Plastic Welding

1Some simple storage rash turned into actual damage on this plastic console from our AMX. A section of the top edge had cracked right off. We were afraid we’d have to locate another console, which could prove costly and time-consuming, so we thought we’d try to plastic weld the piece back onto the console.

 

 

Step-2: Plastic Welding

2We only have so many hands, so the first thing we did was use some aluminum tape to hold the broken piece to the console. Aluminum tape works perfectly here because it holds well, leaves no residue when removed, and the aluminum acts as a slight heat sink to keep the heat from the plastic welder from building up and damaging the surrounding plastic.

 

 

 

Step-3: Plastic Welding

3To be certain that this plastic weld would work on this type of ABS plastic, we found a scrap piece of cracked plastic trim that matched our console to use as a test piece. We taped it up with aluminum tape just as we did the console.

 

 

 

 

Step-4: Plastic Welding

4On the back side of the trim piece, we cut a V-shaped groove along the length of the crack with our rotary tool. We found that a green silicon carbide bit is not too aggressive on the plastic, but still shaves away enough material and remains easy to control.

 

 

 

 

Step-5: Plastic Welding

5The plastic welding process starts by heating up the iron with the special flat tip. Immediately before beginning the welding itself, take a piece of the FiberFlex rod and warm it on the flat tip to just shy of melting. You don’t want it to melt until the rod is actually on the plastic.

 

 

 

 

Step-6: Plastic Welding

6Start at one end of the grooved crack and begin melting the rod so it fills the groove and bridges either side of the crack. It helps to lay the rod along the length of the groove, holding it by the end opposite the iron, and approach with the iron, slowly melting and spreading the rod’s material.

 

 

 

Step-7: Plastic Welding

7The melted rod solidifies within seconds after removing heat. By welding just one side of the crack, the test piece now has nearly all of its former strength back. For full strength, it’s recommended you weld both sides of the crack, though that means eliminating any texture that may be on the front side of the piece.

 

 

Step-8: Plastic Welding

8Assured that the welding process would work on our console, we went ahead and welded the piece back on. This time, we were a little less slapdash with our welding technique and ended up creating something similar to the stack-of-dimes look that most metal welders strive for.

 

 

Step-9: Plastic Welding

9We admit that the weld on the back side didn’t look pretty, but it’s functional, and who’s going to see the back side anyway? We wanted to see what it’d look like if we dressed the weld on the front side of the test piece, so we put a sanding drum into our rotary tool. You can no longer see any evidence of the crack, but the drum did indeed remove the texture from the front side.

 

 

Step-10: Plastic Welding

10On our console, we decided to weld only the back side to preserve the grain on the front side. The section we welded isn’t in a highstress area, so we felt that most of its original strength was good enough. You’d have to look closely to see the cracks, even with the console out of the car.

 

 

 

Step-11: Plastic Welding

11The Plastex kit included the basics: liquid catalyst, powder, pipettes, and small containers for mixing the powder and catalyst. The kit also included a pair of molding bars, used to replicate shapes and textures, and a fiberglass sheet, used to back larger repair areas.

 

 

 

The first method is plastic welding. Though it sounds daunting, it is actually rather quick and easy in its most basic form. While plastic welding can be rather complex, with advanced adjustable temperature airless welders and almost automatic filler feeds, the mostly decorative and totally nonstructural trim we want to repair can easily be fixed with the plastic welding kit shown in Chapter 1 and sold through Eastwood as a basic plastic welding kit.

For those familiar with metalworking, this kit is more akin to brazing than actual welding, in that it doesn’t actually penetrate and melt the base material as it lays down the filler material. Instead, the filler material included in the kit, the FiberFlex rods, are designed to bond to most basic types of plastic and essentially bridge the crack or the gap between two broken pieces. The other part of the kit is essentially a soldering iron with a flat, round tip that’s used to heat the FiberFlex rod until it melts.

Start by plugging in the iron to warm it up, then set the iron to the side. Identify the crack or, if reattaching two pieces, loosely fit them back together like a jigsaw puzzle. Use a piece of aluminum tape to hold the pieces in place, applied to the side of the trim opposite the side you’ll be welding. Note here that most plastic interior trim has a grain on what is called the front side, and as long as you want to preserve that grain, you won’t be welding on that side. Instead, you’ll be welding on the back side of the trim, so it’s important to line up the separate pieces so as to minimize the appearance of the crack on the front side of the trim.

Using a Dremel or any other rotary tool and a pointed grinding bit, cut a groove along the length of the crack on the back side of the trim. Make sure to set the rotary tool to a low speed to avoid melting the plastic from the heat generated by higher speeds. Low speeds also give more control over the rotary tool, and in a situation like this, you can hold the rotary tool almost like a pencil as you trace the crack with the tip of the grinding bit.

Blow or brush away the grinding dust and double-check the alignment of the separate pieces again— now is your last chance to make sure they will go together correctly. The iron should be hot now, so begin by placing one side of one end of the FiberFlex rod against the iron’s tip. Once it starts to melt, place the partially melted end of the rod on the groove you just created in the piece of trim and apply the tip of the iron to the end of the filler rod, moving the tip of the iron back and forth, across both sides of the groove, as the filler rod melts.

Through this process, you hardly need to move the filler rod, so you should start melting the rod at one end of the groove in the trim. The other end of the rod, the end you’re holding with one hand, should be aimed toward the other end of the groove in the trim. Your other hand will be holding the iron, and the iron tip should work its way along the length of the groove, melting the filler rod as it goes. At a minimum, you should use enough material not just to fill the groove, but also to effectively bind both sides of the crack.

The filler material cools quickly, so apply some pressure on the joint as it cools to keep it in place and to minimize the appearance of the crack on the front side of the trim. Once the material cools entirely, check the joint for strength by gently flexing the piece of trim. If the joint appears weak, repeat the process. If not, remove the aluminum tape. Should the piece of trim not have any grain and, instead, have a smooth face, a stronger joint can be made by welding the opposite side of the crack using the same process. To return the smooth face of the trim piece, chuck a sanding bit into your rotary tool or sand the excess filler material away by hand.

Plastex’s Plastic Repair Kit

Step-1: Plastex’s Plastic Repair Kit

1Our ABS dashboard had an integrated speaker grille that had suffered damage by its previous owner. We weren’t in much of a mood to replace the entire dashboard because of this one damaged area, so we thought we’d use the Plastex kit to repair it.

 

 

 

 

 

 

 

 

 

 

 

 

 

Step-2: Plastex’s Plastic Repair Kit

2The simplest repair method seemed to be to use a section from a good speaker grille in a spare dashboard that was damaged in other areas. So using our rotary tool and a plastic-cutting bit, we cut out the section of damaged grille from the good dashboard and cut out a corresponding section of good grille from the damaged dashboard.

 

 

 

 

Step-3: Plastex’s Plastic Repair Kit

3Aluminum tape wouldn’t easily work here, so we decided to hold the section of grille in place with a pair of clamps and work from the center of the dashboard out toward the edge. We notched into the more solid section of the dashboard to provide more area to hold the repair than just the thin speaker grille slats.

 

 

 

 

Step-4: Plastex’s Plastic Repair Kit

4After grooving the mating lines between the two pieces, we mixed the drops of catalyst into the powder, one at a time, and applied the powderladen drops to the grooves with the pipette before the catalyst evaporated. It was laborious, time-intensive, and messy, but we did achieve a finer degree of control over the repair area than with a plastic welder.

 

 

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Step-5: Plastex’s Plastic Repair Kit

5We tried to speed up the process by applying the powder to the mating lines and then dropping the catalyst onto the powder, thus bypassing the onedrop-at-a-time approach. Unfortunately, that trade-off came in a bigger mess and sloppier application. The powder-catalyst mixture also appeared not to seep into the grooved crack as well with this method, which seemed to lead to a weaker bond.

 

 

 

 

Step-6: Plastex’s Plastic Repair Kit

6Once dried, the catalyst/ powder mix becomes as strong as the surrounding plastic and can be sanded and shaped just as easily as the surrounding plastic. The catalyst takes only minutes to fully evaporate, but we let the repair area sit overnight to be certain that it fully cured.

 

 

 

 

 

Step-7: Plastex’s Plastic Repair Kit

7With some black vinyl dye, the repair doesn’t completely disappear, but it definitely looks less obvious than a big hole punched in the speaker grille. A little more time spent dressing the repair area, sanding it down, and applying texture with the molding bar likely would have produced a seamless repair.

 

 

 

 

Step-8: Plastex’s Plastic Repair Kit

8Once the molding bar is heated, it softens and becomes malleable for a short period of time, allowing it to create negatives of any texture or shape. We wanted to replicate the grain on our piece of plastic trim and saw no other way to do it.

 

 

 

 

 

Step-9: Plastex’s Plastic Repair Kit

9The molding bar did indeed pick up the grain, which we could then use to impress on the powder-catalyst mixture as it dried. The molding bar doesn’t seem to stick to any surface, but a light spray with a release agent might not be a bad idea. The molding bar can then be reheated and reshaped an unlimited number of times.

 

 

 

 

The second method of repairing hard plastics is a bit tedious, but doesn’t require heat and can be used for finely detailed repairs. Plastex’s plastic repair kit centers around a plastic resin which, when combined with a liquid catalyst, essentially cold welds most hard plastics and fiberglass. The kit includes three types of powdered resin—black, white, and clear—in small bottles, along with a bottle of the liquid catalyst, applicators, mixing dishes, and a molding bar.

Preparing the broken plastic piece is much the same as the plastic welding method: Clean it, use aluminum tape to hold the broken pieces together, then grind a groove along the cracks and seams. Then choose the appropriate resin. Black resin has graphite mixed in, which gives it additional strength and heat resistance. White and clear resins are suggested for better adhesion. (We found that the black resin adheres just as well as the white and clear resins, however.)

Pour some of the resin into a mixing dish, then with the applicator, pick up a few drops of the catalyst. Add one drop of the catalyst into the resin powder, then quickly pick up the ball of wet resin that results with the tip of the applicator. Apply the wet resin to the crack or seam in the plastic trim, squeezing out another drop or two of the catalyst to make the wet resin flow into the crack.

Plastex designed the catalyst and the resin to seek out their own mixture ratios. Any excess catalyst will evaporate off the repair area, so the more catalyst you use, the better the resin will mix and penetrate the crack. If you use too little catalyst, any unmixed resin will simply blow away and not adhere to the repair area.

It takes a bit of practice and a steady hand to apply the drops of wet resin without making a mess. The tediousness of repeating the process of picking up the resin, applying it to the crack, picking up the resin, applying it to the crack, over and over and over, provides that practice, but leads you to think of other, speedier methods. Pouring the powder directly into the repair area and wetting it with the catalyst there certainly does the job, but can waste resin and make a mess. Also, take care to avoid clogging the tip of the applicator with resin, which will quickly solidify and render the applicator useless.

One thing the Plastex method offers that plastic welding doesn’t is the ability to replicate shapes or textures with the molding bar in the kit. The molding bar first needs to be heated to 130 degrees F, either in hot water or wrapped in foil above a hot plate, then applied to the shape or texture to be duplicated while still hot. As the molding bar cools, it creates a negative mold of that shape or texture. Because the Plastex does not adhere to the molding bar, it can take the shape or texture to be duplicated.

Once the repair is finished, the resin, which dries within a couple of minutes, can be sanded, drilled, or dyed just as easily as the base material in the plastic trim. According to Plastex, the resin actually forms a chemical, rather than mechanical, bond with the surrounding plastic. For that reason, it works well on ABS, polycarbonate acrylic, and PVC, but not so well on plastics that don’t create chemical bonds, such as polypropylene or polyethylene.

These techniques can be used for most types of plastic repair. Fixing cracks is obviously a fairly straightforward process, as is reattaching separated pieces. For mangled or melted areas on a piece of plastic trim that is otherwise salvageable, you may have to cut out that area and find another piece of plastic trim with an undamaged area that you can splice in to your otherwise good piece of trim.

To fill in large areas of missing plastic, it’s also possible to use the screen included in most plastic repair kits (or widely available at any hardware store) as a framework for the plastic repair method to build upon. And for the plastics that don’t easily form chemical bonds, using the plastic welder to soften the plastic enough to sink the mesh screen into the plastic can form a rather strong mechanical bond.

Dyes vs. Paints

Whatever plastic repair method you do use, you’ll inevitably come across a mismatch in the colors of your plastics. The Plastex repair kit mentioned above allows you the option of repairing your plastic trim in a few bright colors, but most other colored plastics require additional steps.

Vinyl dyes, such as Duplicolor’s Vinyl and Fabric Dye or Plastikote’s Ultra Vinyl Color, are often available in rattle cans at your corner parts store, and come in a wide variety of colors to match your plastic trim. Just Dashes, which provides restoration products for more than just dashes, now has a plastic and vinyl recoloring kit called Fade Away. And in the last few years a number of paints specifically formulated for plastics—which means they have had special compounds called flex agents added—have become widely available, including Krylon’s Fusion and SEM’s Color Coat.

The difference between a vinyl dye and a plastic paint comes down to the fact that vinyl dyes penetrate into the base material to recolor it; plastic paints simply lay on the surface of the base material and can later wear away. Most interior specialists recommend using vinyl dyes to recolor plastic trim—dyes are less likely to lift off when cleaning your dash, they leave a more natural (less glossy) finish to the trim, and they don’t obscure the texture of the trim surface.

Test your chosen vinyl dye or plastic paint on an inconspicuous section of plastic trim, such as the back side of the trim or leftover pieces of donor trim, to make sure it looks right and matches your original trim. As with any rattle-can endeavor, thoroughly clean the surface beforehand and spray in a well-ventilated area.

Finally, what holds true for protecting your dashboard (see Chapter 2) holds true for protecting hard plastic trim. Choose a UV blocker without silicone oils. Also, if you’ve recolored your plastic trim, test the protector against your chosen vinyl dye or plastic paint; some protectors have been known to lift dyes or paints. Again, test the protector on an inconspicuous section of the trim first.

By now you’ve probably come across chrome-plated sections of your interior trim—likely on the dashboard or the door panels. If the plating remains in decent condition, that is, it hasn’t been scratched or worn off, you’ll want to mask it before dyeing or painting the piece of trim. Use a good, low-bleed masking tape available at your local hardware store, such as Painter’s Mate Green or Frog Tape. If the plating has been damaged, you’ll have to send the trim piece to a plastic chroming shop, just as you’d have to send your chrome-plated bumper or rocker arm covers to a regular chroming shop.

Glass Restoration

Returning to the doors, you may notice that the glass in the windows has seen better days. It’s a bit scratched, a bit hazy, maybe it even has some paint overspray on it from when your muscle car was assembled 40 years ago. You will have to disassemble the door to take the glass out, so why not take a look at it now, with the door panels already off?

If the glass is scratched, though, it’s your first piece of bad news. Since the late 1950s (specifically, 1957 for Chrysler products and 1959 for GM and Ford products), Detroit used tempered side glass instead of laminated glass in all of their cars. Laminated glass continued (and continues today) to be used for windshields for one big safety reason: It prevents occupants from exiting a vehicle during a crash. Using laminated glass would make sense in side windows for the same reason, except for the need of emergency responders to quickly break into a car and pull a crash victim out. Thus the use of tempered glass in side windows, which breaks apart into those pebble-like chunks of glass.

As the name implies, tempered glass has been hardened to achieve that result. For that reason, it’s often more difficult to scratch than the softer, laminated glass used in windshields, but it’s also nearly impossible to polish out a scratch from side glass. Glass shops do polish out scratches from windshields all the time. Using a polishing compound to keep the glass lubricated and cool, the polishing process actually removes material from the windshield surface until the material in which the scratch resides has been removed, which often results in distorted glass. Unfortunately, on tempered side glass, the only recourse for a scratched piece of glass is to replace it.

Glass Restoration

Step-1: Glass Restoration

1With a quarterwindow out of the car, we can see that glass restoration is about more than just cleaning or replacing the glass itself. A number of guides, channels, rollers, and other mechanisms contribute to the proper alignment of glass and prevention of scratches. Also, trim often adorns the glass.

 

 

Step-2: Glass Restoration

2We removed this window guide from inside a door to show its fuzzy surface and to show how little separates the glass in your car’s windows from bare metal surfaces that can easily scratch the glass. These should be replaced or recovered while you have your door panels off and can access them.

 

 

 

 

Step-3: Glass Restoration

3Here is a typical GM LOF window etching. The SoftRay terminology indicates this window was tinted from the factory, and the date code resides on the second line to the right of the LOF logo. The first letter indicates the month, the second letter indicates the year, and the digit after the dash indicates the day of the month.

 

 

 

Step-4: Glass Restoration

4On a typical Chrysler window etching, the date code is the twodigit number on the right on the last line of the etching. The first digit indicates the month; the second digit indicates the year. The first digit may also be a letter.

 

 

 

Step-5: Glass Restoration

5This is a typical Ford window etching. The date code is the two-digit alphanumeric combination on the left on the next-to-last line. The number indicates the year, while the letter indicates the month.

 

 

 

 

Step-6: Glass Restoration

6Fresh, sharp razor blades can be useful in removing rust stains, paint overspray, and dirt buildup from glass surfaces, and should be kept well lubricated with glass cleaner or lacquer thinner. If any nicks develop in the blade, the blade should be exchanged for a fresh one.

 

Step-7: Glass Restoration

7To clean the glass, always start with glass cleaner. Glass shops seem less picky about the brand and type of glass cleaner than they do about the towels used to apply and wipe away the glass cleaner; the towels should be lint-free paper towels or old newspapers. Continually change the towels to avoid picking up dirt that can scratch the glass.

 

 

 

Step-8: Glass Restoration

8Most glass shops have this special tool, used to remove trim from glass for a thorough cleaning of the surface and for replacement or restoration of the trim. The tool simply hooks onto the lip of the trim and with a couple blows of a hammer, pushes the trim away from the glass.

 

 

 

Step-9: Glass Restoration

9When faced with no other option but to store glass for any period of time, you should wrap it in cardboard and stack it on end, preferably in a place where you won’t accidentally kick it or toss a wrench toward it.

 

 

 

 

Of course, you’ll want to track down the source of the scratch and correct it before installing new glass. Scratch sources vary from car to car and can include guides with the felt padding worn off, wayward screw points, dirt or dust trapped against the glass, worn plastic alignment guides, or even cracked or missing window sweeps. With the glass out of the door, check for all of these, and replace and lubricate as necessary.

When ordering replacement glass, make sure the date codes correspond with the build date of your car. Each manufacturer used different date codes and different glass suppliers (for example, GM used LOF glass, while Ford used Carlite glass), and the coding on the glass often tells whether it’s tinted or not, so check with your particular car club for glass date-coding references. Reproduction glass can even be ordered with the correct date code acid-etched into the glass.

If using older glass or if reusing your car’s original glass (in which case, it’s still a good idea to remove it from the door for cleaning), a brandnew razor blade, in conjunction with lacquer thinner, can make quick work of any paint or undercoating oversprayed onto the glass, or rust stains from metal trim attached to the glass. When using a razor blade, experts suggest keeping it lubricated with glass cleaner to avoid nicking the edge of the blade; nicks in the blade can cause scratches in the glass. General-purpose glass cleaner, applied with lint-free paper towels or old newspapers, will remove any remaining dust or dirt.

Some muscle car windows, especially those in convertibles and hardtops, used thin chrome trim around the edges of the glass and a putty or caulk-like material that cemented the trim to the glass. To clean the glass fully, it’s often necessary to remove the trim, which is difficult to do without damaging it. Most glass shops have a special tool that looks like a deformed railroad tie that safely punches off the trim. For most of us without access to that tool, leaving the window to soak in a tub of soapy water will soften the putty or caulk, though sometimes it’s necessary to slide a razor between the glass and the trim to slice through the putty or caulk. When prying the trim away from the glass, use a wooden or plastic spatula handle to avoid chipping the glass.

Inside the doors, remove any dust or dirt from the felt padding in the window channels. If it’s necessary to replace the felt padding, new felt can be found at a local hobby or craft store. Be sure to buy new felt of the same general thickness as the old felt (some restorers recommend scrap speaker-cabinet felt, which is usually a bit thicker and heavier than garden-variety craft store felt). With the old felt removed and the window channel cleaned, spray the back of the felt with contact cement and work it into the window channel with a tuck tool or other blunt object, then trim the felt even with the window channel edges. The window may seem tight in the channel at first, but by manually raising and lowering the glass in the channel several times, it’ll loosen up. You may find rub strips or rub blocks that require flocking instead of felt padding. In that case, refer to the flocking procedure in Chapter 2.

Relubricate all the window mechanisms with white grease, moly wheel grease, or Lubriplate—preferably brushed on rather than sprayed on in order to contain the mess. If for some reason it’s necessary to store pieces of glass, fold a large, flat piece of cardboard around the glass and stand it on end. When reinstalling the glass, especially on older hardtops and convertibles without much of a window frame to keep the glass in alignment, closely follow the window glass alignment instructions in your assembly manual.

Adding Power Windows and Power Door Locks

Muscle cars didn’t just exist in the realm of low-price, low-option sedans; consider the Chrysler 300H or the 4-4-2 or the Cougar—all performance cars with a touch of luxury added. And normally, that touch of luxury included power windows and power door locks. And it’s alright to admit that you always wanted the comfort and convenience of those options in your Charger or Mustang. The easiest way to add those options, is to find a car like yours with those options and start swapping parts. For power windows you’ll need the motor, regulator, and switch plates. For power locks you’ll want to grab the solenoid and switch plate, plus the wiring harness and the sleeve for the wiring harness as it passes through the door jamb.

Adding power windows can be as simple as finding the correct power window parts from another, better-optioned version of your muscle car, or it can require ordering a power window kit. The burgeoning street rod aftermarket has made universal power window kits widely available and easy to install.

Adding power windows can be as simple as finding the correct power window parts from another, better-optioned version of your muscle car, or it can require ordering a power window kit. The burgeoning street rod aftermarket has made universal power window kits widely available and easy to install.

 

Here is a close-up of the roller guides out of the car. The two white plastic plates, which can sometimes be stamped sheetmetal, sandwich holes drilled in the window glass by the manufacturer. The special socket on the right, available from MAC Tools, has the correct notch spacing for the plate next to it.

Here is a close-up of the roller guides out of the car. The two white plastic plates, which can sometimes be stamped sheetmetal, sandwich holes drilled in the window glass by the manufacturer. The special socket on the right, available from MAC Tools, has the correct notch spacing for the plate next to it.

 

If you can’t find a factoryequipped power window and lock setup, a number of companies focused on street rods, including Autoloc and Electric Life, have developed near-universal power window and power door lock conversion kits that fit in confined spaces. One of the more intriguing innovations to come out of those kits is Autoloc’s power window switch, which mounts behind the door panel hole for your stock window crank. The window crank then fits over the switch’s splined shaft and acts as the handle for the switch; a little nudge in one direction and the window goes up, a little nudge in the other direction and the window goes down. It’s perfect for when you want to add the option of power windows but don’t want to replace your door panels, or want to maintain your car’s stock appearance. Just make sure the splines of the switch match the splines of your stock window crank. Oh, and remember to inform your passengers exactly how the power window switches work before they start cranking on them and damage the switches.

Troubleshooting Power Windows

Most trouble with power windows come from a couple sources. The first one is the roller guides, which serve the same function as in non-power windows, but can see a lot more stress and wear in a power window setup. A power window motor can’t feel when a roller has become worn, deteriorated, or is sticking; it just just keeps cranking and exerting the same amount of torque. When your hand on a manual window crank detects such a situation, it adjusts how much effort to put into rolling the window up or down. New rollers are usually available at your corner parts store or from a restoration parts company that specializes in your car.

 

This is how the roller guides stack together around the glass inside the door. You can see that they’re simply made of nylon and soft plastic. They can easily be damaged if they’re not lubricated and rolling properly.

This is how the roller guides stack together around the glass inside the door. You can see that they’re simply made of nylon and soft plastic. They can easily be damaged if they’re not lubricated and rolling properly.

 

The second source of trouble in power window setups is the power window motor itself. The motors that can’t be replaced can usually be rebuilt, but before going to that much expense and bother, check the wiring, relays, fuses, and switches in the power window circuit.

 

Written by Daniel Strohl and Posted with Permission of CarTechBooks

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