James Schooley writes:
These are the dowel pointers I use to make the Cone Scarf.
The bits I have ground to shape from spade bits.
I made the small pointers were made on my lathe,
the big one I stock along with other tools I sell from my store front.
I have been using my invention "the Cone Scarf" to make repairs
and haven't seen one give out yet. Using the reground 1" spade
bit in a drill press, I cut a cone into one part of the break.
Next I make a matching cone shape using the 1" dowel pointer,
and glue this in with a slow cure Epoxy, T88.
Then I do the same procedure with the other end of the break,
the new wood becomes a sort of double ended cone once it is
all shaped. The second cone it then Epoxied into it's respective
cone shaped hole. I have put these same breaks together so
perfectly that after sanding there is only a minor crack to touch-up.
I am not at all concerned about putting the big seat screw back
where the original was. BTW this double cone scarf ends up
being about 3.5" long and 1" wide in the middle, plenty strong.
These are some photos of a complex leg scarf repair that we
recently completed in our shop. This childs wardrobe came in
with a broken/missing leg. The missing wood involved a great
deal of wood extending into the double mortise area of the leg.
Originally the leg was about 44" long reaching from the top of
the wardrobe to bottom and held two tenons at the top and two
more at the bottom. The leg was also shaped along the face,
and with all this complexity I decided to build up the missing
square stock and scarf in the new turning, since it was such
a mess, I figured I had nothing to lose.
We used a 1/4" cone bit, it is about 1.25" long which gives a nice
long transition for the repair surface to get a strong glue bond.
Working around the tenons we loaded the entire splice surface
with 1/4" square sticks and Quick Wood where necessary until
we had the missing shape rebuilt. Then just cut off the long ends
and Cone Scarfed in the new leg.
Stress tests left me convinced that it will hold up fine.
James Schooley
Iowa
