Classic Car Tech - Cowl Vent Removal/Shaving

The Vent Cowl.
These are some of the most misunderstood and problematic of areas for classic cars. The vents have two purposes, first remember A/C wasn't a standard option back in the day. These provided fresh air into the cabin via two vents under the dash. Unfortunately they don't work at all, in my opinion. Fresh hot air coming into the cabin, is still just hot air. The second reason for the vents was the passenger side fed the factory A/C, if you opted for the feature. Luckily today, most aftermarket A/C packages no longer use these, because nine times out of ten rain pools up in the cowl causing rust. Especially in states like here in Florida. There are a couple options to stop this. Some use magnetic covers or snap on cowl covers. Neither of which to me are very attractive. And since we are already heavily modifying this mustang we are going to weld them shut for good.

Starting my using a thing gauge sheet metal, cut to fit the openings. Then with them in place mark out the edges and cut out the old openings. make sure mark which side goes where as the may vary slightly, also doesn't hurt to also add top incase they get flipped around.

Using the Tach Process, start by making small welds in the corners. Using a magnet to hold in place will make this a lot easier. Once set, continue to make several small welds around the permitter making sure to not heat up the metal to much, it may cause distortion if you do. Once you have completed your welds, using a 4" grinder to knock down the welder and a diegrinder with a heavy grit sanding disc will finish up the welding process quickly and easily.

Scuff the cowl a little using a heavy grit paper (used 80 here). Applying a couple light coats of bondo filler to sand smooth. Using a block sander here will insure you get out any high spots from any metal distortion you may have gotten. If you took your time earlier most of this filler will be removed by the time your finished sanding. For the sanding, Start with the same 80 grit as earlier. Then stepped down to 160 and finally to 220 to finish it out for priming.

Your final product should leave your cowl looking factory closed and baby smooth.