For quite some time I toyed with the idea of adding a dummy right hand filler cap for that 60's look but it didn't sit well with me to have a fake item just for show. Whilst weighing up my options, it occurred to me that I could re-purpose it as a location to house a battery isolator. Something I wanted to fit anyway to disable the power during long periods of inactivity.
After spending some time searching for suitable isolator switches. I settled on a 200amp unit with removal cap. Mainly because I liked the look of it and partly having a removable cap would make it more secure.
Once received I started by taking some measurements of the switch to work out if it would fit inside a filler neck, and how I could mount it. The easiest solution was to 3D print some flanges that could be bonded inside a steel tube.
3D Printed Flanges
Once printed I was able to bond them to a steel tube by using a polyurethane adhesive (PU18). To set the correct height and ensure they were level, I 3D printed two fitting tools visible in the left-hand picture.
The right-hand picture also shows two holes I drilled and tapped into the brass cap collar in order to secure it in position.
Paint and Assembly
Prepping The Car
I made a template of the passenger side filler neck hole location, flipped it over and used it to mirror the position on the drivers side.
The hole was marked out, centre punched and cut out using a purpose bought 68mm hole saw. This wasn't the nicest job to do on a freshly painted shell.
I drilled a small hole in the cap and purchased a snap keyring so I can carry the cap around on the car keys without the fear of loosing it.