Step 1: Tools and Materials
Free weights (for "clamping")
You'll need a book that is a little larger than the object you are making a case for. The kindle measures 7 1/2" x 4 3/4" x 7/16". The book I used measures 8 1/2" x 5 3/4" x 1". I considered many books, and spent some time looking at some old books trying to find one with a clever title, like Fahrenheit 451, or Catching Fire, but ultimately settled on a sketch book that had no title at all, just a clean black cover. It just felt a little more sophisticated.
For the foam, I was looking for both dense and firm. In the foam world, density is a measure of how big the cells of the foam are, and firmness is a measure of how hard it is to compress. I found a kick board that was being thrown out at a local pool and while it felt a little too rigid at first, after cutting it to size it was perfect. I also considered using wood and strategically placed Sugru, but the foam kick board proved easier for making adjustments.
Step 2: Cutting
While you have your knife out, cut your foam to shape as well. I wanted access to the power button and headphone jack, and wanted to the leave the speakers clear as well so I opted for two foam cutouts that look like brackets, i.e. [ ], that will go full length along both sides of the Fire and just come around the corners on top and bottom by about 1/2".
The brackets themselves measure 1 1/4" wide by 8 1/4" tall overall, with a cutout on one side that measures 3/4" by 7 1/2". they are just under 3/4" thick.
I also measured and cut the felt to size. I wanted enough to cover the white paper that was on the inside cover of the sketchbook, roughly 8 3/8" by 5 1/2".
Step 3: Gluing
I used polyurethane glue to adhere the foam in the hope that as it foamed and expanded, it would work it's way into the foam of the kick board. I think it worked well. I used a thin bead of glue, then spread it with a razor blade to get coverage everywhere, but keep the glue layer thin. This really helped minimize any "foam out" from the glue joint.
With the glue spread thin, I misted it with water to activate the glue and carefully placed it on the edge of my cover. I then closed the book and leaned some free weights all along the edge to act as clamps and let it sit overnight.
Next day, I used the same process to glue the bracket along the spine side of the book cover.
Step 4: More Gluing
Place the felt down and carefully push from the center to the edges to get it to lay flat without any puckers.
I used another book and the free weights again to clamp and let it sit overnight.
Step 5: Spacer Pads
Step 6: Final Thoughts
A few of things I would consider if I built another. First, the spine seems somewhat weak and I think it could need reinforcing at some point in the future. I am thinking about using fiberglass cloth and rubber cement so that it is strong but retains the flexibility that I want. Second, it might be nice is to get a book that is a little larger than this one and add some cutout space in the foam for headphone or synch cable storage. Lastly, I would consider an elastic band to keep the book closed. just a couple of eyelets and some 1/8" black elastic band under the first foam bracket would do the trick nicely. Oh well...Live and Learn.
Post pics if you make one of your own!