Today I finally finished installing the hinge on the front face of the headrest.  I started by digging out the foam from the hinge mounting area on the top part of the headrest.

I dug out as much foam as I could using the razor knife and then I switched to using the Dremel tool.

As I got the foam dug out to the proper depth it was obvious that both the plywood insert and the hinge flange would not both fit width-wise, so I shaved a few more layers off the plywood by the approximate width of the hinge flange.  I had already shaved off a couple of layers off the plywood previously, but it clearly required another thinning.

Before I thinned the plywood insert, it was so tight that I had to add tape to it in order to remove it.

I measured the hinge barrel width at 0.180 inch, so I simply halved that to remove 0.090 inch from the outer glass layer on both the top & bottom hinge mount, to center the axis of the hinge along the line between the top and bottom parts of the headrest.

Below you can see where I cut out 0.090″ for proper hinge positioning.

After mocking up the plywood insert & the hinge flange to ensure a proper fit, I mixed up some flox using fast hardener and slathered it into the hinge area.

I also cut 4 pieces of duct tape to protect the holes at each end of the respective tabs on the hinge.  I then inserted the plywood insert & the hinge into the slot that I created on the front face of the upper portion of the headrest.

While the upper headrest portion’s hinge assembly cured, I started prepping the hinge area on the lower headrest structure.

I tested the width & fit of the plywood insert in the same way I did on the upper headrest structure.  The plywood insert for the lower headrest structure needed to be thinned down as well.

As I was ready to pull the trigger on the lower hinge, I double-checked the first hinge assembly.

Having used fast hardener & then putting the heater on it had it cured in no time flat.

Since the top hinge half was cured in place, I used it as a template for the bottom to get a near-perfect fit.  I taped a strip of packing tape across the abutting plywood inserts.  I then floxed in the lower hinge and gave it about 20 minutes to cure before I mounted the top hinge half to the bottom hinge half.

After ensuring that no unwanted flox was getting into places it wasn’t supposed to, I ensured the upper & lower headrest assemblies were aligned.  I then taped the parts together with duct tape and to minimize any gaps I weighed down the entire structure.

After 30 minutes passed with the headrest in front of a heater, I removed the tape and weight to check the rotation of the hinge, and to make sure that there was no flox gumming anything up.  There was a few bits of flox here & there that I removed with a toothpick, but the hinge rotation was great and all looked good.

Here’s a quick video discussing the headrest hinge: