Some of you may remember my thread about redoing my '66 fastback. What started as a simple engine repaint turned into an entire stripping and refinishing of both the undercarriage and the engine bay. One of the things I was really dreading was recreating the spray sealer originally applied to the firewall. Thankfully, I had pictures of the unrestored engine bay, so I had a good reference point. I was concerned about getting the appropriate build-up and thickness, as many of today's products just don't have the build qualities of what Ford used originally.
As you'll see from the pictures, my car had the greatest amount of sealer around the blower motor area. I had several products on hand to try. First, I had some leftover Fusor 805 spray sealer from doing another car's wheelhouses. I also went to Lowe's and picked up a can of Rustoleum undercoating, as well as a can of truck bed liner. In the end, however, the only product I used was the Rustoleum undercoat. It really surpassed what I was expecting out of an aerosol can. I tried several different test areas on some scrap metal, and it would allow several coats to build up, without each successive coat dissolving the one underneath it, as some undercoating products tend to do. I was very pleased with how this turned out. Though it isn't visible in the pictures, it appeared to do an excellent job of sealing grommets and heater hoses to the firewall, much like what Ford used.
So, for comparison, here's two pictures of the original, unrestored engine bay:And here's a picture of the almost finished product. I still need to install the master cylinder and A/C lines and spray sealer around them.