[Woodcarver] inserting fins

[jackcarves at juno.com]

Hi Maura, Jack Miller here. 
I have carved many fish and also fish decoys.  The fish decoys use
metal fins, but for the decorative fish, I use wooden fins.  I
construct the fins from thin slices of poplar which I cut on my
bandsaw.  I use poplar because of its strength and also because it is
readily available to me here in Pennsylvania. 
I carve the body of the fish first and then draw the outline of the
body on the poplar strips for the dorsal and ventral fins so that I can
get the profile right.  Then I draw the outline of the fin- its
profile- and then cut it to approximate shape.  Next I cut a hole to
accept the fin in the body using a dremel and a small diamond or
carbide bit.  This plowed hole should be at least 1/4 inch deep and
maybe deeper depending on the girth of the fish. The fins near the gill
covers I have to draw free hand.  I usually make them a lot bigger than
the final size so that I can adjust the size and the shape when doing
the setting of the fins in the body.
As to the thickness of the poplar strips, that will depend on how I
want to treat the curvature of the fins.  Most fish species can move
the fins in many different positions, especially the fins near the gill
covers- these fins can move almost in a circle depending on the
species.  The thicker I cut the fins the more mateial that has to be
removed.  
Also the thickness of the fins needs to take into account strength
issues.  I make the fins extremely thin at the edges and thicker the
closer the fin section is to the body.  This is not totally accurate,
but it's an area that I feel needs to be accounted for, just as when I
carve a bird the primary and tails feathers are thin on the edge and
thicker as they get nearer the tail or back.  It's another example, I
believe, of using optical illusion to support a carving and to trick
the viewer into thinking that the structure is thin throughout.
Once the fins are carved and there is a hole plowed I insert the fins
after filling the hole almost full of yellow glue (Elmer's carpenters
glue or Titebond whichever I have available) and let the joint dry
thoroughly.  Later I inspect the joint and fill any small gaps with
Elmer's Carpenter's Wood Fill.
Maura , I hope this brief description helps you complete your project.
 Please let me know if I can provide any more information.
Carvingjack Miller