Inside a car door
Most sheet metal doors are made of three parts. There is a frame (to which the inner door panel and armrest are attached), a window channel (which is welded to the door frame), and leather (which attaches to the door frame and outside the window channel).
Body repair shops usually remove damaged steel door skins and attach new ones.After painting, the door looks like new again. Not long ago, installing a new sheet metal skin meant that it had to be plug welded to door and window frames at dozens of locations. Plug welding replaces spot welding used in factories. Since most of us do not own MIG welders (or no welders at all), re-skinning the door is not a job done by ourselves.
However, thanks to the specially designed modern two-part adhesive, the body shop can now bond the new door skin to its frame. These adhesives can also be used by backyard mechanics, so now you can re-skin the door at home. Advantages: glue can produce a stronger repair effect than welding.
Taking Off the Door
To change the skin, remove the door from the car and remove all parts that may affect the removal and installation of the outer skin.
The procedures differ depending on the vehicle, but the starting point is to remove the inner door and windshield panel. Then remove the insert inside the window channel and any finishes or moldings around the window frame and on the door trim. You must also remove the mirror, the lock, and the door handle. If you have doubts about how to remove these items without causing damage, please use the garage repair manual.
Unplug any wiring that extends from the body to the door frame. Then write around the door hinges on the car body to mark its location, then have an assistant hold the door while unscrewing the hinge bolts. Note that even if much of the door’s inner workings have been removed, it is still heavy, so get adequate help.
With the door closed, you can now start to separate the sheet metal skin. The periphery of the surface is folded on the door frame at the factory. Grind the edge of the door edge until the flap on the back of the door is separated from the skin that forms the door surface. After bypassing the entire door, it should be possible to peel the folded sheet metal from the door frame. Wear goggles and gloves when grinding-the edges of the metal are sharp. We are very serious.
After removing the folded part of the skin, look for a spot weld that fixes the skin to the frame. They are likely to be found near the bottom of the window opening, the area around the fixed point of the door mirror, and the top of the door skin under the door handle. Spot welding is usually difficult to see. The most effective method is to use strong light from a certain angle to find traces of their stories. When you find the weld, mark it with a felt pen.
Spot welding can be removed simply by drilling. But this will leave holes in the door frame. Instead, individual drill bits made specifically for this task are used. It is sold in auto parts stores with body repair supplies. Because the teeth of the drill bit are spot welded, the drill bit will cut the metal around the weld, but will not damage the frame.
Remove the spot weld, keep the folded part of the skin away from the frame, and gently pry it away from the door. If resistance is encountered, stop and ensure that all spot welds have been drilled. The manufacturer also places the sealant between the door skin and the side impact beam. (This is a solid piece of metal that extends behind the skin and connects to the door frame.) You must pry this connector apart.
Believe us, the interior of the door is dirty. Clean it with compressed air-you may even need to clean it with pressure. Use a body grinder to remove small circles of spot welding material remaining on the frame. Any putty, glue, or other materials that can affect the skin’s installation should also be worn off or polished. Then clean the door frame.
Give me some skin
There are several ways to buy door skins. If your car or truck is less than ten years old, you can buy it at a dealer. Aftermarket suppliers also provide replacement products, which can be purchased online and in many auto parts stores. Remember, factory door skins are usually more expensive. For example, the price of Chevy pickup in 1998 was about $ 350. The shipping cost of the skin after-sale is about $ 260. No matter where your skin is, please open the box and check it immediately. These things are more likely to be damaged in the car than in the car.
To install the skin, place the door frame face up on the table. The sheet metal part folded around the door frame is at a 90-degree angle to the surface. In this way, the skin will correctly position itself around the structure. Before installation, place the skin on the frame to test its suitability, and then remove it. You may have to wear off some flaws or dig out high points to get a perfect fit. This is an important step-once the adhesive is in place; any mismatch will not be corrected.
Adhesives and their applicators can be purchased in auto parts stores that sell body repair shop supplies. The door glue (non-sag door skin glue) we use is packed in two 7-ounce containers and requires equal mixing. We bought a special applicator made by an adhesive manufacturer for about $ 65-the the price of about two adhesive containers. When we apply them, the applicator gun and its disposable nozzle mix them. This particular thing takes an hour to set up. Warning: Do not do this job with epoxy resin in 5 minutes. Please use products for body repair.
The adhesive is sensitive to temperature. You need to work in a temperature range of 60 to 85 F. If the temperature is too low, the glue will not be set correctly; too much heat will harden it before all fixtures can be set correctly.
To paste the door skin, use a 1/4 inch thick hole. The beads of adhesive on the applicator will come into contact with the skin on each surface of the frame. Apply several layers of glue to the side impact beams so that the middle of the skin will be firmly fixed to it.
Use spring clips or small C-clamps-many-to hold the skin in place as the adhesive cures. Make sure that all parts of the skin are in contact with the frame. Use paper towels to wipe off excess adhesive.
Let them harden the adhesive for 2 to 3 hours. Then place a piece of old but clean carpet on your worktable after removing the clamps, and put the door on it with the skin facing downwards. Inspect the excess glue again, and then grind or sand it off. Then, with a hammer, start at one corner of the skin and work the entire perimeter of the door, bending the tabs along their length until they are flat against the frame.
Take slowly on this last move. Go several times along every seam to crimp the metal over. Don’t stain the skin outside your new door.
Now the door is ready for primer and paint. Don’t forget to paint the inside of the skin first to prevent corrosion. Follow the paint manufacturer’s recommendations to determine how many layers of paint and drying time are required. Keep all drain holes on the bottom edge of the door free of adhesive and paint; if they are blocked, water will accumulate inside.
You and your helper will then reinstall the door on the vehicle, making sure the hinges are compatible with the marks you have made on the exterior. To get the door gaps right, you might need to make minor changes, because the new skin may fit slightly differently.
When the door is in the car again, reinstall all removed components.