Saturday, September 4, 2021

Gap seals are all done (updated)

Not entirely sure why the time was right now to do the gap seals, but they're all done now nonetheless.

By the time I got to doing the last aileron, I finally had the wing gap-seal technique down...

  • pre-shrink the cloth to 120C.  Its texture is mottled, but that's okay
  • use a piece of blue painter's tape 6in in length for marking.  Find the attachment 2" on the wing side, and locate using the TE adhesion point as the alignment feature.
  • hold the 2" fixed side in place with a thumb and flex the surface through its range, which will pull the loose end of the tape to reveal the end of the 6" strip.
  • figure out the end of the adhesion on the control surface
  • mark the ends and the adhesive contact point ends.
  • pull a string or a flexible long straight-edge to mark down the length of the whole wing.
That isn't a complete description for marking, so ask in the comments if you want to use this method and need more.
  • once marked, put adhesive on both fixed and control surface sides. Let dry.
  • iron the fixed side on the wing.
  • prop up the control surface at the angle of maximum stretch of the gap seal.
  • pulling a 3" section at a time, iron the gap seal to the control surface side pulled taut.  There will be some wrinkles still, but get it overall pretty close.
  • iron the control surface side of the gap seal
  • increase temperature and pull the gap seal itself taut across the gap.  Flex the control surface occasionally to make sure you're not over-tightening.  If so, the Stewart Systems method allows the gap seal to be pulled off without penalty.
  • second gluing and wiping (only on the glue joint).  Let dry.  
  • iron at quite a warm setting, including tightening the gap seal to its final stretch.  Do this with the control surface propped up again.
  • paint 2x coats of Glidden Gripper white primer diluted 3:1 paint to water ratio.  I do one coat horizontally, then one coat vertically with a foam brush.
  • lightly sand with 220 grit the pinked edges and remove any boogers to make the skin surface smooth
  • final coat of paint
  • accept imperfection

Marked for the gap seal, ready for adhesive:

Just starting the fixed side pre-placement before ironing:

Flap gap-seal done, showing how it looks, with the aileron (foreground) ready for the fabric.

Aileron gap seal done & painted:

No word from the DMV yet on the trailer title & tags.  Based on previous timing, I'm not expecting anything in return until about November. (updated: it arrived the same day of this post!)

What else remains?  I pondered this recently...

  • DONE - Get trailer title & tag
  • Modify trailer to safely haul Goat
  • Find an appropriate airfield to do the maiden
  • Mount GoPro(s) for maiden flight documentation
  • Backyard final assembly and thorough pre-flight check, including weight & balance
  • Go do the first flight!

Some other things on the eventual list...

  • add leather patch to wing tips where will rub the ground
  • install leather patch guides for elevator control lines
  • replace the nose tube (because the holes are twisted)
  • Trim color paint
  • Wing root kiss seal
  • Wing tip dolly
  • Wing wheel
  • Strut fairings (after flying to figure out the right angles)
  • Emergency parachute
  • Real variometer (LXNav with a TEK probe is my intention, if it is sensitive at low speed...)
  • Drogue chute
  • Motor mounting revisit (need guy-wires that means some un-covering and subsequent repairs)
  • Finding a "real" field for flying more regularly
  • Place to store goat at home and/or at the flying field
  • USHGA "hang 3" rating so I can fly at cooler sites??

Super random ---- I made it by the US National Sailplane Museum in Elmira, NY and found two of Goat's cousins:








1 comment:

Eric Y. said...

I haven't been by the page in awhile and saw it in my bookmarks. Its good to see you making progress. I like the forward mounted electric. "Someday..."

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