Instrument Panels ~ Final Finishing

Back side of cured part for side panels.

Vacuum bagging of the instrument side panel material was a success however the part compressed more than we thought it would so we didn't achieve the desired thickness necessary to surface match to the center panel.  That's ok.  A small lip down from the center panel to the side panels still works. One would think 8 layers of cloth would make for a thick part.  Eight hours of -28InHg vacuum really bleeds all excess resin resulting in a very nice 50:50 fabric to resin ratio for the part.

Left and right side panels were cut to exactly match the aluminum back plate.  This required a lot of careful cut, fit, sand, repeat.  The holes for the AOA, ELT, and side vents will be cut after clear coating.

After a great deal of measuring and cutting, the assembled panels created a nice fit with a tight adjoining seam. The panels are ready for clear coat

Center and side panels were scuff and cleaned.  Wax & Grease remover was used as a final cleaner to ensure that all contaminants were removed prior to painting.

Master painter, John Branchaw, carefully applied four layers of clear coat to each panel.

Finished carbon fiber panel.

Clear coating gave the panels a rich finish with great contrast.  The TeXtreme 1000  2.95oz uni-directional tapes created a very nice checkered pattern.  A few easy cuts for the AOA, ELT, and air vents and the panels were finished.  Overall, a great finish to a fun project.  Many thanks to John Branchaw for prep and paint work!

Next step, mount the avionics trays and install the avionics.

Instrument Side Panels - vacuum bagging

Finish sanded layer of SuperFill that was applied to panel mold.  Waxed mold and misted a few coats of mold release.  

Our goal is to surface match the side panels to the center panel.  This requires a material buildup to equal the thickness of the center aluminum piece plus the carbon fiber overlay.  A quick calculation determined that we would need six layers of fiberglass plus two layers of carbon fiber.  A 50:50 resin to fabric ratio requires 128g of resin.  That's a lot!

Eight hours later...  Removing the bagging material and bleeder-breather layers revealed a very tacky part that had clearly not yet finished curing under room temperature and good vacuum. 

We'll leave the part exposed to a strong morning sun for a few hours to finish the cure process.  

Wing tip - inside plug fabrication

Used 88g of liquid urethane expanding foam poured onto release play lining wingtip inside surface. The 15x expansion created a good size plug.  Next step, fiberglass wet layup using the plug to press the glass to the wingtip surface.  We may even vacuum bag the plug to the surface so as to minimize epoxy weight and maximize adhesion.

Fabricated wing tip mold plug.

Instrument Panel - composite sides

Sanded mold for side panel pieces.  Applied a layer of SuperFill. Will be ready to sand and start vacuum bagging this evening.

Avionics wire cleanup

Continued with avionics wire bundle cleanup.  Disconnected, clipped, and re-pinned a number of wires.  Ran two wires from Hxr JA-25 to Garmin GTN-750 DSUB-47 1001.

Arjan & Mike working it out