In order to finish off the repair of the leaky fittings on the brake master cylinders, it was necessary to bleed the brake lines once again. This time, Bernie and Mike K. were able to lend assistance yesterday morning with the brake line bleeding chore. The left and right brake lines were filled with fluid from the calipers up using the same pump oiler and method used before. However, this time around it appeared the brakes were still a little spongy, so with most of the air out of the lines we switched tactics. I got inside the cockpit to pump on the brake pedals as Mike continually added fluid to a tube connected to the brake fluid reservoir while Bernie worked the bleeder valve at the caliper and monitored for air bubbles coming out of the line. The whole process took us a while, but the brakes appear to be quite solid now and so far, the fittings on the master cylinders are remaining dry.
With the brakes functional again, it was time to get back to working on the
W-1222 wingtip extensions for the navigation & strobe lights. The next step
for installing the W-1222 wingtip extensions involved flipping the wings upside
down which Mike helped me do. With the wings upside down, a batch of resin
mixed with flox is applied to the inside edge of the W-1222 extensions to fill the
void between them and the W-1204E wingtip ribs. Prior to applying the
resin/flox mixture, the areas around the wing that could come in contact with
the flox are to be covered with wax … as is typical at DOG Aviation, this was
taken one step further, in that the contact areas were covered with clear
packaging tape and then Vaseline was smeared onto the tape as the release
agent. There is also an area on the W-1222 extensions that needs to be
protected from the flox so a nut can be installed later in the assembly process
… Van’s suggests using a plug of modeling clay to protect the area from the
flox, which was done.
A plug of yellow modeling clay is used to protect a location that will
be used for a nut to secure the mounting bracket for the nav/strobe lights. Looking
closely at the area my finger is pointing to, one can see the line of the packaging
tape which was rolled over the outer edge of the wing tip. Another strip of
tape was used on the other side of the wing adjacent to the outer edge. Prior
to applying the flox, the packaging tape was slathered with Vaseline so the
extensions can be removed to work on the electrical connector and the mounting bracket
attachment after the flox mixture cures.
After applying the flox mixture to the inside edge of the W-1222
extensions that will contact the W-1204E wingtip ribs, the extensions are secured
onto the wingtips using Clecos. It appears the main reason flox is used here is
to fill a void between the W-1222 fiberglass extensions and the W-1204E wing
tip ribs … because after the flox mixture cures, it is necessary to drill two
more rivet holes through the extensions and into the W-1204E wingtip ribs …
that area can be seen between my fingers in the photo below.
After the resin/flox mixture is applied to the inside edge of the W-1222
wingtip extensions, the extensions are secured onto the wing using Clecos to hold
position as the resin/flox mixture cures. After the flox has cured, the area between
my fingers will receive two #30 holes for rivets.
Prior to leaving the hangar for the day, I wanted to get a little more done so the ELT antenna and bracket was installed. This has remained off for access, but now that the fuel tank and rear window are now installed, figured it was time to mount the ELT antenna. Nothing out of the ordinary here so no photos were taken since this was covered earlier this year ... it was just a matter of installing three screws and attaching the antenna wire to the connector on the base of the antenna.
Now that the flox has had time to cure overnight, the first order of
business today will be drilling the two#30 rivet holes, then remove the extensions to
continue with the mounting of the bracket for the navigation & strobe lights and the electrical connections.