December 29th 2007 6.0 hrs - 76.5 hrs total. Retrieved jig and lumber
from Steve's shop. Was quite a task to get it into the "shop" in the
basement. Had to remove part of a door frame to get it in. Cut all the
slots in the spars. Sanded the spars and a couple of other peices I had
missed. Tried making a test scarf joint with the disc sander - not very
succesful. Only a couple of ribs to make and I'll have all the parts ready
to start asembly.
December 30th, 2007 3.5 hrs - 80.0 hrs total. Prepared epoxy for first
use. Experimented with different methods of making scarf joint and finaly
just did it by hand on the belt sander. The layers in the plywood make
excellent depth and angle indicators as you sand through them. Made a
sacrf joint on the elevator spar, preped and epoxied it together. Learned
some lessons about glueing! When compressing the scarf joint with
clamps, the peices will want to spread apart and move. I now know to
clamp both peices firmly in position before compressing the scarf joint!
Learned a little about the glue too. Evven though it was a very small
batch, it still "cooked off" in the end and changed from a thin honey
texture to very stif tar texture in about two minutes.
Tail jig with stab rear spar scarf joint being glued.
December 31st, 2007 2.0 hrs - 82.0 hrs total. Picked up about 20 or so clamps today, also some mixing cups and a
box of latex gloves to keep the epoxy off my hands. When I got home and unclamped one end of the elevator spar it
moved about 1/4 inch! So there is now about 1/4 inch of reverse dihedral in the spar! After cleaning up the glue from
the joint, flexing the spar in different ways, and consulting the plans, I think I can salvage the spar and correct the
"bend" with the flanges and blocking that is yet to be installed in the elevator. Went ahead and made the scarf joint in
the stab rear spar and glued it. With the elevator spar I only had 4 clamps. With the stab spar I had plenty of clamps
and ended up using 12. In the photo above you can see part of the completed elevator spar laying in the bottom of the
jig, the two halves of the stab front spar stacked on top of it, and the stab main spar clamped to the top.
January 1st, 2008 - 4.5 hrs - 86.5 hrs total. Took the stab rear spar out of the clamps - turned out perfect. Cleaned
up the joint and sanded. Made the scarf joint in the stab front spar, glued it, let it dry, took it out, cleaned it up -
turned out even better than the last one! Finished up one of the stab tip clamping forms. Cut out and sande the other,
still need to cut the clamp holes in it. Ripped some long fir stock into appropriate demensions for flanges. One of the
peices of stock was in pretty bad shape so I was only able to get one flange out of it. Means I'll need to make a visit
to the hardwood shop again. Sorted and laid out the ribs on the spars. Did some trail fitting. Should be able to glue
the flanges in place next.
January 2nd, 2008 1.5hrs - 88.0 hrs total - To get the flange to follow the curve of the spar I put finishing nails
through the spar slots into the jig. Put down blue masking tape to keep epoxy from sticking to jig. You can never
have too many clamps! Went and got some more wood for last flange. Still need to rip it to size. Talked to guys at
EAA meeting about warped plywood. Used steam iron on 1/2 inch pkywood trim tab spar to try tor straighten it
out. Looks like it worked. Have it calmped to a table and will let it dry for a day or so to see if it stays fixed.