Priming and Painting

 We are focused back on priming and painting of several different parts. The boot cowl and top cowl were painted in the paint booth with a couple coats of vestal white.  Residual dust was sanded and buffed/polished off. While those parts were inhabiting the paint booth, we were able to prime the door frames outside on a nice day.   

Boot cowl ready for paint

Top cowl with coat of vestal white

Door frames primed

The lower cowl was also masked and prepped for paint.  There will be only a small area of white on the top as most of the lower cowl will be painted orange.  Also, several aluminum pieces were primed (outside again).  This included flight sticks, seat adjustment pins, plus several canopy and door brackets.  We tinted the primer gray for these pieces as most of the interior is gray.  Hours: 23

Wing Repair, Side panel painting

We transported the wing from the hangar to the garage which gave us another opportunity to use the new trailer.  The wing had previously encountered some damage when a pipe fell against it in the hangar, which put a small hole through the fabric.   We cut the ragged edges off around the hole, sanded the area, applied glue, and installed a fabric patch over the hole.  The patch area was shrunk by applying heat with an iron.  

Small patch added over the hole in the wing

Once the patch was completed, a couple coats of primer were applied to the patch with a paint brush, and once dry, the area was sanded.  We then masked off all of the wing except for the section where the patch was.  Unfortunately, our modified paint booth was too small for the wing, so the wing protruded through the large front door, which we then sealed off with plastic.  Two coats of Vestal White were shot over the patch area, and then the whole section was sprayed with a blending agent (Hot-temp reducer) to eliminate halos.  This last step was recommended by the paint manufacturer for repairs and it seems to have worked.   As usual, we ended up with some dust in the paint, so these areas were sanded and then we polished that whole section.

Wing section (with patch) repainted

We also repainted a couple of fuselage side panels (near the foot wells).  NACA ducts had been added to these panels, and our previous attempt to paint them outside with a small paint gun did not turn out well, so we just sanded them and reshot them with paint in the paint booth.  We still need to fix a few issues (as usual) with dust in the paint, but overall they are looking decent.  The bottom of these panels will eventually be painted orange.  Hours: 21

Painting top section of side foot-well panel

Fuselage moved to hangar

In order to gain space back in the garage to fix a wing and do some more painting, we moved the fuselage to the airport.  Wanted to get a new trailer as the old one wasn't super stable (narrower wheelbase and taller deck).  Had a difficult time finding a trailer with wide enough deck for the gear, but found one in Greensboro.  The plane fit nicely and we had about an extra inch on each side between the wheels and the trailer's wheel wells.  With the fuselage out of the garage, we can now focus on getting the garage cleaned up a bit and the paint booth back in operation.  Hours: 8

Plane loaded up and ready to go

Unloading at the hangar

Door latch guard, paint planning

We created two U-shaped guards for the door latches out of thin stainless steel.  To bend the metal precisely, we created a jig made of wood, and pushed the metal into a channel with a metal bar to create the U-shape.  This worked well.  Below is a picture where we were testing the jig with a piece of aluminum first.

Testing the jig

We also spent some time planning on how we are going to paint the cowling, and where exactly we will place the from white to orange.  Hours: 8

Paint planning

Leak fixes, Cowl, Door frames, Control sticks

 After last engine runup, we had found we had 2 leaks, one from the brakes and one from fuel.  The brake leak was at the bottom of the Grove landing gear at a right angle fitting. The brakes were drained, and the wheel was removed to get access to the fitting.  The right angle fitting was then removed and cleaned.  Locktite thread sealer was applied, and the fitting was installed with an extra turn to ensure it fit snugly. 

Brake fitting tightened

The fuel leak was coming from a fitting that went from a T-fitting near the fuel filter to our fuel-pressure-sender.  This one was a bit complex because of all the interconnected fittings and hoses.  But this gave us a good opportunity to change our fuel-bypass orifice as we learned ours was slightly oversized ( The ideal orifice size was 0.35 mm, and ours was about 0.88 mm).  Our orifice fitting came from JEGS, and is essentially a hole drilled in a set screw, which is then screwed into a special AN fitting.  Using a small mill with a tiny drill bit, a 0.35mm hole was drilled in the center of a new stainless set screw.  This took several attempts as the tiny drill bits were easy to break, but we got it done.  The new orifice was installed, and the leaks were addressed.  After the fixes, we ran the fuel pumps (which boosts the system to 50 PSI) and checked for leaks again.  None were detected. 

Fuel leak fixed at this T-fitting

The new 0.35mm fuel-bypass orifice is in the top of this T-fitting

The cowl pieces, which had been previously primed, were sanded down with 320 grit sandpaper so that they will be ready for painting, although we won't get to that until the paint booth is back in working order.

Next we turned our attention to the doors.  We previously made a couple of center aluminum strips that cover the seam where twoLexan panels meet.  We wanted to close up the ends of these, so we filled them in with a little bit of epoxy (JB-Weld) which was sanded flat once dry.  This is mainly cosmetic, but does make it look a little nicer when installed. These strips were also sanded lightly to get them ready for priming.

Epoxy added at the ends of center door frame strips

We also wanted to decide on the color to paint the door frames.  We were originally thinking of using gray as that matched most of the interior and existing powder coat, but also considered black as that helps create more of an unobstructed view out of the airplane.  We wrapped the frame in some spare black vinyl we had to get an idea of how it would look.  We liked the result, so we will likely paint the door frames black now. 

Experimenting with black door frames

Lastly, we drilled a couple of small holes in our control sticks for the wires that will go to the push-to-talk switches.  We are going to making the control sticks removable, so plan to add a small connector that will make the wires easy to disconnect.   Hours: 27

Hole drilled in control stick