lead in page showed the wing as I received it and this shot shows the
fabric now stripped off and the wing cleaned up a little bit.
Since the fabric was left on and the root ribs had metal caps over the
lightening holes, the insides were really very clean. The most we
found was a few dead bugs, some dirt and an occasional drilled out
rivet end probably from the original rebuild. We used a shop vac
with a small diameter hose extension to get down through the inboard
ribs into the D-tube area. We also turned the wing onto the
trailing edge to get any other objects out and right now there doesn't
appear to be anything rattling around in there.
The mobile stand is actually from
an old LK-10 trailer that was designed to allow one person to do the
complete assembly. It allows me to tip the wing counter clockwise
so it is laying flat with the top surface up. I also allows me to
easily move the wing onto saw horses to work on the bottom surface.
took this picture to remind me where the drain holes go on the
aileron. As it turned out I didn't put that many in, rather using
the diagram in the restoration manual that had fewer but what appeared
to be enough. The aluminum was power washed with cleaning
chemicals by a professional paint shop and it was well worth the money
versus trying to strip the paint and primer by hand. At this
point I have also removed the old tip wheel that had suffered some
corrosion damage and you can see the dark area at the tip where dirt
had collected under the reinforcing plate.
you ever wondered what the moving parts inside your wing look like
after years of use and squirting oil on them through the spoiler
opening or inspection holes? Well here is your answer. The
one redeeming factor
on the wings is that there are a lot fewer parts to take out, clean and
then reinstall. I took a lot of pictures like this to show how
everything goes back together. Notice the surface corrosion on
the aileron push rod and fortunately there was no damage that would
have required replacing them. They were stripped down to bare
metal primed and painted with a epoxy coating. There was a lot of
holding fabric to cover the spoiler opening (notice you can't see
through the wing) so it all had to be
stripped off which was hard since there isn't much room to work inside
that part of the wing.
is a shot from the top side with the fabric covering having been
removed. Unfortunately I forgot to tell the paint shop about
opening the spoilers so they didn't clean the underside of the spoiler
but so regular stripper made short work of it. To the left you
can see the Teflon guide for the aileron push rod. These replaced
the wooden ones and make the ailerons feel a little lighter while
reducing much of noise from the tube rubbing on the wood version.
not change any of the settings on the spoiler or aileron push rods so
all the control throws would remain when putting everything back
together. However, the spoilers did require a small adjustment
when we got to that point so they both opened at the same time by the
same amount. At the bottom of the picture you can see the lap
joint of the leading edge skins. The dark gray area was where the
Bondo had been applied to smooth out the joint. I elected not to
redo those joints from a time and weight perspective.
here is what the spoiler bellcrank area looks like now and ready for
covering. Rather than creating a mess with contact cement again,
I installed some simple strips of aluminum to provide a surface for
Taking regular fabric into this area, then shrinking it and cutting out
the area for the push rod. This also provided a little added
thickness to bring the spoiler up more even with the wing skin. One
thing that came up during the final IA inspection was fraying on the
cable you see coming off the bellcrank. It was the first thing he
looked for since he had just found it on another 1-26 and it required
replacing the cable that goes through guides inside the wing you cannot
reach. It can be done, but you have to be very careful.
are some shots of the aileron bellcrank area after taking off the
fabric. There wasn't anywhere near the mess of the spoiler area
this was an easy cleanup and re-install. From the top picture you
can see where dad installed ball bearings on the bellcrank, which also
has contributed to the easy feel of the ailerons. After Harry did
the first flight in his replacement 1-26 I asked him how well it
answer "like a 1-26". Upon further query he admitted that the
controls didn't feel as smooth as those on #026 so all the work dad did
with Teflon guides and ball bearings seem to have gotten the desired
results. The push rod from the fuselage and the push rod between
the bellcrank and the aileron also have ball bearing ends.
The casing running chordwise through
this area actually contains two wires that could be used to hook in
wing tip thermal sniffers if they were ever developed. Harry did
this during one of his covering jobs, but I didn't need the weight so it came out.
here is what this area looks like now. The chromate on the
ribs and spar all look pretty good considering it had been done back
around 1963. There were some areas where I had to spray on some
epoxy primer to cover the bare aluminum but it was minimal. As a
reminder, make sure to double check all the attachment points for
cotter pins and any free play. Ask someone else to also do a
check before you start putting on fabric.
top photo are the tip wheels that came off the wing. You can see
there was some rust and corrosion so I started looking at alternatives,
including a set from K&L Soaring.
got an idea for a different type of tip wheel after looking at George
Powell's arrangement. It looked clean and simple to build and
provided adequate ground clearance for the aileron but I needed to make it a little more unique. It starts with a
six inch piece of aluminum tubing with a wall height of three inches
and a width of one and a half inches from McMaster
Carr. (Cost about $10 plus shipping for a one foot piece.) I
drew the shape on a template to give it a little character rather than
just a simple triangle shape like George's. After transferring it
to the tubing I drilled the axle bolt hole to make sure it was straight
through both sides of the tubing that was about to become a
channel. I cut out the shape on a band saw and rounded the edges.
Since the sheet metal on that part
of the wing is only .020 thick it needed some reinforcement. I
moved it forward on the wing chord to get more substantial material for
attaching it. I
made plates out of .070 aluminum that would pick up the bolts in the
wing tip stiffener and could be riveted to the last wing rib as well as
include the wing tie down hole.. I
originally wanted to put the plate on the inside to make it a little
cleaner, but that was going to
take way too much time and effort so I went with the external method
that isn't very visible when on the ground.
Here are a couple of shots of the finished pieces. The front of
the channel is held in place by the normal tie down bolt. I
purchased the standard ones from K&L Soaring since it appeared to
be about the same cost as having something welded up locally.
Since the bolt is only installed finger tight with a castle nut and
safety pin, I figure I can easily replace it with a regular AN bolt
when flying or knowing I don't have to tie it down on the flight line
for some period of time.
The backing plate has two blind
nuts that take 10-32 bolts to provide the last part of the attachment
of the bracket to the wing. This allows for removing the bracket
for any reason and gives it very good rigidity against side
I compared the weight of this
arrangement with that of the tip wheel available from K&L and it
seems this is a little lighter. Obviously it doesn't give as much
ground clearance, but then I don't plan on landing off-field as I am
content with local area flying.
.....Now that the glider is done I have
found they are working really well and that I can move it around by
myself. The skate wheels are holding up well so far as is the one on
the tail wheel.
Here are the wings back from the paint shop where he did an acid etch,
then alodine to prep the surface and finally an epoxy primer. You will notice that he
left a two inch bare metal area completely around where the fabric
needs to be Poly Taked to the skin. There will also be a two inch
tape overlapped along the edge of the fabric so there is a pinked edged
facing the air flow across the wing as prescribed by the plans.
For those who are realy observant, this is not my trailer.
We happen to have this short trailer from a Rigid Midget sailplane in
the hangar. The glider had been donated to a soaring museum back
east but they didn't want the
trailer. It has been handy for things like this and fits well in
the hangar as you may have seen in the background of some pictures.
The ailerons were the first things to be covered on the wings once I
finished with the
basic learning process and practice on the elevators. The plans
called for gluing the fabric to the rigs with no screws or rib
stitching necessary. These are now up through the initial two
coats of silver and sanded awaiting the final silver coat.
is the starting point for getting fabric on the wings. Per the
Schweizer diagrams you start with inboard trailing edges covering the
bottom portion first then the upper side. Follow the instructions
from the STC'd system you are using to attach the fabric to the
structure. In my case the Poly Fiber system uses Poly Tak with a
pre-coat then another wet coat to press through the fabric as you apply
the fabric. The Schweizer instructions call for a 2 inch overlap
for the forward facing edge and at least a 1 inch for the chordwise
edges. I used 2 inches all around. The blue tape helps keep
the Poly Tak from getting all over the primed skins during
application. As you will see below the spanwise seams will get a
4 inch tape to hold everything in place due to the forward facing of
bottom portion is now covered. The rear edge of the fabric that
overlaps the trailing edge piece previously glued on has a one inch
overlap that will eventually get a 3 inch tape to cover all the edges
and provide the necessary thickness over the rear spar edges. It
still needs the inspection cover and drain holes that will be added
after the first hand brushed coat of Poly Brush dope.
is the top of the outboard section of the wing with the fabric glued
on. This was easy since it is smaller than the bottom and simply
overlaps the rear spar so is a flat wrap around the edge. I have
found the technique of ironing the edges around the spar does provide a
cleaner bend in the fabric and removes the chance of air bubbles along
the edge as the Poly Tak is applied.
The blue tape is going to be moved back from
the edges to allow for applying the hand brushed coat of Poly Brush
that will provide the base for adding the seam tapes. This will
help keep the primed areas clean for final painting.
is a photo of the wing fabric in its lose state before the initial and
final shrinking with a common household iron. The pink along the
edges is a coat of Poly Brush that has been worked into all the
areas where the Poly Tak may not have gotten complete adhesion.
This seemed like a good idea since this is the main point of fabric
attachment to the aluminum and was suggested by one of the IAs overseeing the project. Once it had completely dried the
shrinking was done in stages up to the final setting based on the covering STC.
left photo shows the first coat of hand applied Poly Brush that gives
the foundation for adding the necessary reinforcing tapes on the ribs
and along the edges. The right picture shows where the rib tapes
have been applied starting from the middle of the spar seam to a one
inch overlap on the aileron spar. There is tape span wise along
the aileron spar to help hold down the chord wise rib tapes. In
this shot you can see where a 4 inch tape has been applied along the
spar line using Poly Brush with a small amount of Poly Tak added for
better adhesion to the surface. So far this looks like it worked
quite well since none of the edges have broken loose as the spray coats
of Poly Brush and Poly Spray (silver) have been applied. This
application was a compromise between the Poly Fiber and original
Schweizer processes and was acceptable to the IA without wrapping
fabric around the leading edge. You might check with your IA on
whether you need to use the medium grades of fabric or if light would
be okay due to the lower Vne speed of the 1-26. This would save a
lot of weight and came to light when I was too far along to change.
of this point the right wing now has two coats of Poly Fiber Spray
(silver) and will stay that way until the left wing gets its two coats
of brush and two coats of silver. The next step for the wings is
to mount the ailerons and install the hinge line seal with Poly Brush
so the last coat of silver will cover the tape. I plan on
installing the seal on the underside of the hinge line so it is not
readily visible from the top. I think this is the cleanest
method. Most of the fuselage is up to the second coat of silver
so when the wings are done everything will be ready for the final
this point the aileron has now been reinstalled on the wing in
preparation for putting on the gap strip. There are plus and
minuses to this step due to the problems it can cause during the color
painting operation. The plus is everything gets painted at
the same time rather than individual pieces. The down side is
holding the aileron at various angles to allow for getting the color
into all the areas. I have also made new hinge pins that have
right angles at one end to prevent it from going through the hinge and
then the other end is bended 30-45 degrees to prevent it backing out
but allowing for unbending it in the event the aileron ever needs to be
is the start of the gap strip application. This is 2 inch pinking
tape that is applied with Poly Brush ensuring that the fabric is pushed
into the gap a little bit so it sort of forms a hinge like
appearance. I found you had to be careful here to make sure
the tape doesn't get glued to the edges of the wing and aileron spars
since it needs to have some freedom of movement.
gap seal is now completely installed and ready for silver. The
bottom image shows how the seal fits in the gap. You can also see
that I did not put the seal over the hinges since I felt the airfoil
through them would be so low that it wasn't worth gumming up the hinge
with glues. The odd spots on the aileron are sanding points done
after the second silver coat. These will get covered up when the
last silver coat is applied.
the gap seal and the entire aileron have been given the final coat of
silver so this wing is ready for color, at least on the fabic
areas. I still need to make the big decision on what types of
color to use on the fabric and metal areas so there is a consistent
appearance between the two area.
This is the last piece for the wing rebuild section since the next step
will be final paint and that result can be seen at the bottom of the fuselage rebuild page.
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