Over the past two months we've covered the installation of a Vintage Air A/C system on my project '49 Chevy. Something you may have noticed missing were the louvers in the dash. The reason for this was because I didn't want to mount them under the dash where they'd be less effective at blowing air toward the driver and passenger's upper body, but I also didn't want to mount them in the dash, as I was hoping to maintain a period appearance inside the car. However, I finally decided to french them in the dash and make them as unobtrusive as possible.
I chose Vintage Air's Proline Rotary Vane louvers because I felt they were the most "retro" looking (if any aluminum A/C vents can be retro) and decided to make a hammerform to fabricate frenched housings that I could weld into the dash. Given that the dash is curved, I simply couldn't drill it and bolt the louvers in place anyway, so why not make a detail out of it?
Hammerforms are simple to make, and can be used to fabricate a variety of small panels. While I could have just welded a blind tube into the dash and ground the welds, doing the job this way allowed a nice radius to the edge of the hole in the dash, and made the welding easier. If you're going to make hammerforms, MDF is ideal, as it is available in various thicknesses, is easy to work with, and is strong. I used 3/4 inch plywood, as I only paid 20 cents for this offcut plus the hardware store had no MDF and I knew I'd only need to use it four times. However, MDF will last longer and won't split as plywood is wont to do.
