Now seemed like a great time to fill all the holes in the firewall before I did a lot more work on the front end. After removing the stock heater/defroster and fresh air equipment, I was left with some sizeable holes, not to mention all of the holes used for wiring, lines etc. Since my experience with panel adheasive had gone so well, I decided to try a larger project, make a template of the firewall area, then use the plasma cutter to cut a new panel out from 18 ga sheet metal. Instead of welding the new fire wall in, I planned on using the panel adhesive.

The plasma cutter requires a 3/16″ offset from the edge of the tip to the center of the cut. To account for this offset, I used the template to cut a female template that was 3/16″ larger so that it could be used as a guide for the plasma cutter. Paper guides can be used for cutting with a plasma because the heat is so localized at the nozzle that the outside of the tip is cool enough not to burn the cardboard. After cutting the sheet metal, I did a test fit and located where the 2 1/2″ hole for the wiring harness had to go. I also had to locate an access hole and mounting holes for the master cylinder.

The biggest problem with this project was figuring out how to clamp the new metal in tightly while the adhesive cured. Some vise grips, pieces of angle iron and some blocks of wood solved the problem!

After the adhesive had cured, I went back and reprimed the engine side of firewall with epoxy black. I will go around the edges with seam sealer before finally painting it a nice satin black. The interior side was primered with grey epoxy.

New Firewall