Once your cowl panel is removed, you can look at its condition and decide which repairs need to be done. Often times, the lower cowl panel is in good shape and only needs to be cleaned and re-painted. However, if it is rusty, a patch panel will need to be installed. Dynacorn Industries offers a good reproduction repair panel. It is a complete lower cowl panel replacement, so you won’t need a patch panel.
I’ve used several of these and they work great. Keep in mind that this panel is patterned after a 1967 Mustang. So if you are using the panel on a 1965 or 1966 Mustang, you will need to drill an extra hole in the mounting flange of your left hand fresh air intake canister. 1967 Mustang fresh air intake canisters had more mounting stud holes than a 1965 or a 1966 did.
To achieve the proper placement of this extra hole, place your fresh air canister on the cowl prior to installation and mark the mounting flange.
Another thing to keep in mind: if you are repairing a 1965 Mustang cowl panel, make sure that your windshield wiper transmission protrudes high enough through the top of the exterior cowl panel. This ensures that you have enough of the wiper transmission protruding through to put the chrome bezel on it. If this isn’t done during installation, it is difficult to do once the painting has been completed.
Here is a tip on avoiding paint overspray inside the Cowl Panel. After you have removed, repaired, and repainted your 1965-1968 Mustang cowl panel, you are ready to reinstall it. Here’s a neat tip for avoiding any paint overspray in the cowl panel area. Use aluminum foil! The aluminum foil catches all the paint overspray that would accumulate in the vent area of the Mustang cowl.
Here’s what to do: prior to permanently welding the cowl lid on your Mustang, line the cowl floor with aluminum foil. Then, weld your cowl lid to your Mustang. When you are ready to paint your Mustang, this aluminum foil will prevent any overspray build-up to the inside of the cowl panel area.
After your vehicle has been painted, simply reach up inside the air or heat intake holes, grab the foil, and pull it out. This leaves a nice cowl interior without the ugly paint “scale” (paint buildup) that is commonly left in the cowl panel area.
Here’s an additional benefit of using aluminum foil: If the aluminum foil is carefully placed, it will also prevent weld sparks or blobs of hot metal from burning the painted cowl panel during the welding process. Aluminum foil works much better than any plastic or paper masking material.
Nearly all 1965-1968 Classic Mustangs and Cougars should have their cowl vent panel removed. This area harbors hidden rust, ugly scaly paint overspray, and water leaks. If not repaired properly, rust will continue to eat away at the cowl panel and then the firewall. You’re better off taking care of the cowl panel before this nightmare happens.
Upon removing the cowl panel, clean, repair, repaint and re-install it. Here are some tips for how to re-install the cowl panel.
- Align the cowl panel. Make sure when re-installing, that the position of the cowl panel is correct. It should line up evenly with the rear edge of the hood. It should also line up evenly with the front fenders. Temporarily install the hood and fenders to get the positioning correct. Self-tapping screws work really well for temporarily installing body replacement panels. When the cowl position is correct, attach the cowl with a few self-tapping sheet metal screws. This will temporarily hold the cowl in proper position. Remove the hood and fenders so that you have access to the cowl.
- Weld the cowl panel. Beginning from the center of the cowl panel and working outward, make a plug weld every 2-3 inches. A plug weld is a weld that fills a hole in the top piece and attaches to the bottom piece. This type of weld is about 1/4″ size. Complete the plug welds until you have welded the entire panel.
- Grind the welds. Using an air or electric grinder, grind the excess welds so that they are flush with the cowl panel.
- Seal and fill the welds. Using a quality seam sealer or body filler, fill any grinder marks or unwelded holes. Once the sealer or filler has cured, sand the area smooth.
You are now ready to paint the cowl area and permanently reattach the hood and fenders.