While Denys forges ahead with works on the dear old Friendly, we toilers in wood have been engaged in our own battles, between a bit of repair work on the workshop building as alluded to by Denys in a post above.
With the repairs around the cockpit complete, the fuselage is now strong enough that we could, for the first time remove the prop from under bulkhead#2 at the forward end of the cannon bay. What was revealed was not pretty:
Looking across from the port side quite a bit of rot is evident:
It looked worse from underneath:
Probing with a chisel revealed that the laminated lower section on the port side was completely buggered about 4 laminations deep. With these cut away, rot was also exposed in the laminated member running forward from the cannon bay:
There was also a soft spot uner the skin on the port side above the opening, and investigation revealed rotten balsa and a hole through the inner skin. The rotten section of the fore-and-aft member has been cut away here. The circular hole is for a Dzus fastnener retaining the access panel for the cannon.
So to repairs. New laminations were made and applied to the bottom of the bulkhead:
New timber was applied to the end of the fore-and-aft member, and the fuselage skin feathered back to receive an eventual patch. The ply on the rear face of the bulkhead was so bad that I stripped off quite a large section, which nicely reveals the construction details:
One of the uprights at the centre of the bulkhead also turned out to be quite rotten, so again new timber was shaped and fitted:
As the damaged section of the inner skin is inaccessible from the inside, a patch was applied outside:
New skin was applied to the rear of the bulkhead:
New balsa and a skin patch was installed on the outside:
The front ply was in better shape, but a couple of small rotten areas were cut away:
And patches glued in:
On the starboard side the damage was a lot less severe, and we got away with replacing only the outermost lamination:
As well as a relatively small patch of skin on the aft face of the bulkhead:
And a bit of filling on the forward face. The entire lower part of the bulkhead will be covered in fabric, concealing most of these repairs:
In order to make the repairs the joining strip from the middle of the aft face of the bulkhead had to be removed, and as the bottom edge was a bit rotten a new one has been made ready for installation:
In preparation for applying fabric to the lower part of the fuselage, the last of the original fabric was stripped away from the opening for the trailing aerial under the starboard side of the cockpit, and a blanking plate curved to fit the profile of the fuselage was made by laminating thin sheets of Paxoline:
Meanwhile Dagy has been busy making parts identified as missing when we assembled the tail feathers. Two such were the aft struts for the tailcone:
These are made from steel, and as you can see from the drawing are absurdly complex for what they are, with a second piece of steel tube sweated into the flat end and the forked end reinforced with a third piece of steel:
Dagy has also been progressing the repairs to the outboard sections of the wing (the only bits currently accessible). Here new reinforcing members are clamped in pace while he uses a 'hole finder' normally reserved for metal work to pick up the original screw holes:
New material has been spliced into the outer end of the rear spar:
And part of the webs of the spar and outboard rib have been replaced:
Aft of the trailing spar is a curved lightweight fairing which covers the forward edge of the aileron. This was almost entirely missing as you can see from the above image. The fairing is supported by ribs made up from blocks of spruce with plywood faces. Here are some original and new ribs:
And the totally awesome and readable drawing for said ribs:
Inside the end rib the tiny paxoline ring carrying anchor nuts for the wingtip wiring connector had completely disintegrated, and a new one was made and installed with great difficulty and much swearing:
Even something as 'simple' as the bottom skin of the wing is quite a complex part made from two different thicknesses of ply spliced in four places:
With much of the repair work to the end of the port outer wing completed, Dagy has started looking at the starboard end. Here the rot has extended to a couple of the lower stringers, into which new wood has been spliced:
The plywood supporting ring for the oval access panel has also seen a big repair:
Going forward, once I finish with bulkhead #2 and get some fabric on it, we hope to remove the tail and move the fuselage across the workshop. Then we'll have more space to work on the wing sections, and once Dean has built us the much needed fuselage brace, we'll be in a position to drop the wing centre section out.
Cheers
A