Monday, February 18, 2013

Healthy Bones Finished (Bone Comb)

This is the Daddy in action.  My daughter snapped a few rare photos of me in actin.  Sawing one of the sections of the comb.


Based on the finished pieces I've seen it appears that the cross section which holds the various pieces together was riveted on before the teeth were cut.  I decided against that approach as I was afraid that I'd break some teeth (which I did) and didn't want to have to pop the rivets out to fix it.  

  


I tried sketching the lines which were to be cut, but as it turns out simply eyeballing it worked better.  I ended up not following the lines which I had drawn anyway.


My little two pound anvil from Tandy Leather worked wonderful for this.  I didn't use a vise which I've seen in period paintings.  I simply held the bone in my hand and used the round portion of the anvil foot to saw against.  It provided just enough support behind the bone without cracking it and yet allowed the saw blade to proceed unimpeded.


As I proceeded I started scoring the end with my saw to mark the spacing.  I was trying to make sure that the last tooth ended up about the right size.

 

As I proceeded I broke one of the sections of the comb.  I was also a bit inspired to try some more things.  To get my next project up and running I went out and bought two more bones from the butcher.  This is what the "raw" materials look like before I started.


CRAP!  My nightmare came true.  I broke it.  Trying to file the teeth.  Running the file along the teeth works well.  Running it across the teeth not only makes a high pitched annoying sound, it also cracks teeth off.  Perhaps that is why they shape the whole comb and put it together before cutting the teeth.


Should I throw this section away.  Nope.  I cut it off the end and filed it smooth.  The comb will just be a little shorter now.  I plan on keeping this section for display of my FAIL, but also plan on making it into a needle since it is about the right size to start with anyway.


Almost done and ready for assembly. Before I go any further I need to practice.  This was the scariest part of the whole project for me.  I've peened rivets before, but never against a know-to-be fragile bone background.  I was so afraid that I would peen it, miss hit and crack the comb.  I drilled a hole in two scrap bones and tried a rivet.  WORKED GREAT!  Very slow and tedious work, but I found that about 1/16th of an inch extra protruding from each side worked great to hold the pieces together as if they were born that way.

 

Here is what the first test rivet looked like.  No polishing or sanding after the hammering was done.

 

Testing my spacing.  I have a lot more refinement to do on the teeth, but I planned on waiting until all the assembly was done.  Sketched out a piece of paper about the size I wanted to use. You can see that the overall construction technique is consistent with the extant comb on the right from the 15th century.

 

Here are the two combs, almost done.  I'll probably sit and fiddle with the teeth a bit more while watching TV, but I'm happy saying that this piece is done.  Notice that I took a small hand drill to make some small decorative dimples along the cross section.  I wanted a little embellishment  but was still afraid of weakening the structure.  Maybe more embellishment on my next comb attempt.