Firewall Cleaning, Repair and Painting: Part 1

With the repairs completed to the windshield frame it’s time to move onto getting some cleanup work done to the firewall and front clip so that they can both be reinstalled on the body.

The firewall will be the first component to be reinstalled on the body, so that’s the first piece that will be cleaned up. The goal will be to remove all the goop and gunk on the firewall, remove the excess bonding compound that was left over from disassembly, and to sand, smooth out, and paint the firewall.

Below are several shots of both the inside (foot well side) and outside (engine compartment side) of the firewall.

 

Of course in order to complete a thorough job of this task most of the miscellaneous ties, brackets, and plates need to be removed so that they can be cleaned separately. The majority of the wire clips, brackets and plates on the firewall came riveted from the factory so removing them was simply a matter of drilling out the rivets and popping the pieces out of place.

With all the miscellaneous small components removed, my focus was switched to removing the excess bonding compound and adhesive from the flanges of the firewall. As shown in the photo below, there was quite a bit of excess bonding compound and fragments of  fiberglass stuck to the flanges of the firewall. In order to get everything properly reassembled and aligned this extra material needs to be removed.

The bonding compound very much like Bondo and I found that a DA sander with some 80 grit paper made pretty quick work of this task. A word of caution though, while removing the excess bonding compound you need to be pretty careful not to sand away the fiberglass flange of the firewall! It can be easy to get carried away.

Fortunately, it’s pretty easy to tell where the bonding compound ends and the underlying fiberglass begins. As illustrated in the photo below the bonding compound is a very light uniform color whereas the fiberglass is darker with lighter striations from the fiberglass fibers.

Here’s a shot of the side of the firewall after removing all of the excess material.

With all of the excess bonding compound removed I switched my focus to removing all the gunk from the windshield wiper tub. I can best describe this as a very tenacious rubberized undercoating that sticks like glue. After years of aging the material was heavily cracked (thus reducing it’s water tightness) and covered with overspray from a previous paint job gone wrong so it definitely had to go.

I started with a putty knife and rubber mallet to remove the majority of the material, but this stuff was really tenacious…

…so I decided to use a chisel to scrape away the material. This worked much better but, for obvious reasons, required a bit more care and attention to avoid damaging the fiberglass.

Once the rubberized material was removed I went over the entire area with a wire brush to smooth things out and to remove any stray pieces hiding in corners. Again, be careful not to get too carried away, the wire brush can dig right into the fiberglass if you’re not careful.

And here’s a shot of the cleaned out wiper tub, an obvious improvement over what was there to start!

Stay tuned for the next update where I’ll start some fiberglass repairs to the firewall! In the meantime, please stop by the forum to say hello and see what folks are talking about.