Saturday, 6 September 2008

The Starboard Aileron - Part 2

In part 1 of renovating the starboard aileron I covered the disassembly of the aileron. Now I can cover the start of the reassembly.

Over the summer, progress was slow as I was waiting for delivery of much of the materials required for the restoration from the US. This took longer than I had originally anticipated (my advice to anyone restoring an aircraft would be to order at the earliest possible date, preferably before you start the restoration as long as you have a good idea of what will be needed). Now that everything is here I can start work again on the aileron.

The first job is to repair the crushing on the spars caused by over tightened bolts that hold the aileron hinge brackets on. You can see in this photograph how the spar has been crushed down around the bolt holes.

The approved repair method is to glue a plywood patch into the recess then sand it down so that it is flush with the spar. This provides a new flat surface on which to glue the plywood doublers for the hinges.

I arranged the plywood so that the visible grain is arranged along the length of the spar.

Simple G-clamps are used to force the plywood into the recess. Aerodux adhesive was used as it is easy to apply with a small paintbrush and any excess can be wiped off with a damp cloth.

Note: you cannot glue the doublers in place yet as this will prevent you from sliding the ribs back on.

All the aluminium parts were etch primed and then sprayed with an epoxy primer to provide a barrier against moisture. I have purchased a 4 stage HVLP turbine with a grvity feed gun for all the spraying. The turbine provides a separate air feed for a half face mask which is a must when spraying with most of the paint systems which can contain some very nasty chemicals. You must ensure that the turbine is located in a clean air source and that wherever you are spraying, the area is well ventilated. For most of the work at the moment I am sparying outside when conditions allow.

All the ribs laid out in order (thanks to them being stamped with a locating number) prior to being slid back on to the spar. I will not nail the ribs on until I have glued the doublers on and revarnished the spar. It all seems very awkward because the ribs have to be on the spar early in the process.

The ribs are slid on in order (and checked against the port aileron which is still assembled).

I then mount the aileron in a make shift jig; two axel stands, which will be used to support the aileron while I put it back together.

I can now begin to glue the plywood doublers back on to the spar. This will take a few days as the glue requires about 24 hours to cure. As each doubler is glued into place I will need to ensure that I drill the bolt holes otherwise I end up with all the doublers in place with no clue to where the holes should be (duh!).

I must say it feels good to see something coming back together at last although there is still a long way to go as I haven't started cleaning up the leading edge or the hinge hardware yet.

Another job looming are the door frames as I have just received some Ash timber so time permitting I should be very busy during september.

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