Cowl Sealing and associated Repairs
A common problem experienced by Maverick, Comet, and a large number of Mustang owners is a leaking cowl area which allows moisture to drain into the vehicle during inclement weather conditions.
This condition is caused in part by the rusting away of the interior metal pan areas directly beneath the cowl vents which in turn permits the water to drain “through” the damaged areas and onto your floor inside your vehicle. This also leads to the rapid deterioration of floor pans since the water does not evacuate and then the carpet usually holds the moisture and starts then promotes the rusting process.
One method of correcting this condition would be to drill all of the existing 100 or more plug welds out and remove the cowl so you can reach the inner areas and then either repair, or replace the entire section if you can find the proper metal pans to do so. Then re weld the new metal pan part back into the proper position and “Of Course” you would at this time administer a waterproof coating to insure this problem would not resurface again.
The method “we” chose to deal with this problem is shown in this article which depicts the removal of the louvered areas in the cowl entirely, welding metal inserts in and the subsequent repairs to the damaged areas with metal capping and fiberglass application layering over the damaged areas after treating with OSPHO.
Since we instituted and developed this procedure in 1997 (twelve years ago) we placed the information on our website to assist other Comet and Maverick owners in dealing with this problem. Some of those that have chosen to follow suit and seal the cowl vents on their own cars have given us a positive feedback. We have performed the process on six of our own personal cars with success in ALL cases and we are “updating” our page with more details and photos to further assist other Maverick & Comet owners in this procedure.
 A die grinder was used to cut out the louvers leaving one eighth inch of materials for our crimping/stepping tool. We made an edge all around the opening to provide support for the metal patch we will be installing later. |  After cutting, we ground the edges carefully to smooth any sharp areas for safety since we will be putting our hands and arms into these openings to remove the debris that has accumulated over the years. |  Although we didn't show it, you can see the edges are “stepped” and provide a ledge which will support the patch we are going to fit into the openings. We cut out a cardboard pattern, fit it, then cut metal. |
 The pattern is being cut out with scissors and we will fit it “precisely” before transferring it to the 16 gauge sheet metal and is then fitted again to insure we didn't miss anything. Before any patch is applied, cleaning is performed. |  Test fitting the metal patch into the opening before we actually tack it into position and prepare for the welding operations. We tack on one end, then move to the other end for another tack and continue this process. |  One side tacked into position and we will work on the other side around the wiper arm area. Notice the interior areas have been coated with Ospho for treatment of rust, then several coats of black paint. |
 The second area is being test fitted before we tack it into position. The center of the patch must be raised slightly to provide a smooth edge. Welding is performed in a hop scotch method and a quench cloth. |  This area has been welded, ground, and is ready for a little body work and then the paint will be applied. Welding was a slow process since we “quenched” each weld afterwards to prevent warping. |  This is a photo of a “finished” cowl vent seal area after painting. Looks factory doesn't it? We used photos of three different cars in this page since I couldn't locate all the photos that were taken. But you get the idea. No Louvers! |