SNB-P13: Cowling

Rough sanded micro on upper cowl then final sanded; upper cowl should be finished with most micro work. Added micro to two low spots on lower cowl and let micro set. Fine sanded the two spots on the lower cowl with 120 grit; finally micro work should be finished. Laid out side exhaust vents onto…

Removed upper and lower cowls from fuselage and removed packing tape from fuselage. Rough sanded new micro; most spots very close to being done with fiberglass but a couple of spots needed more filler. Leaving cowls off of aircraft, mixed another batch of stiff micro and filled the couple of low spots in both the…

Rough sanded aft edge of upper cowl then pinned into place on fuselage. Further sanded cowl on fuselage to get spacing correct. Removed upper cowl and sanded transition line with 120 grit. Removed lower cowl to trim prop hub area and prep a few small spots for epoxy. Reinstalled cowls and secured into place. Prepped…

Removed lower cowl from fuselage and removed hinges and clecoes. Rough sanded new work with 60 then 120 grit; transition mostly okay with just a few low spots to fill in. Reinstalled lower and upper cowl onto aircraft. Marked prop hub trim line with 3D printed guide to maintain 0.125″ clearance between hub and cowl.…

Fine sanded upper cowl with 240 grit to see if latest application of micro filled in low spots; overall looks good. Will try to use some high build primer to help with pin holes but overall upper cowl looks good. Reinstalled both upper and lower cowls onto aircraft then pilot drilled mounting holes through upper…

Removed upper cowl from lower cowl again and began sanding upper cowl. Started with 60 grit and moved up to 240 grit sandpaper to better blend transition area. Finished sanding with upper cowl mocked up onto lower cowl to better blend transition. After sanding most of the new work with 240 grit, discovered a few…

After allowing epoxy to cure, used 60 grit sandpaper and hand sanding block to rough shape cowl curvature and knock down spatter and high spots. Tried to focus on transition areas between existing cowl and new work to make transition smoother. Initial sanding identified multiple valleys and pin holes that will need another coat of…

After leaving the fiberglass to cure for a couple days, marked rough cut line and gently pried the top cowling off of the bottom cowling without incident. Rough sanded upper cowl using 60 grit sand paper to level bottom edge and start to feather transition area. Temporarily installed top cowl back onto airplane to check…

Prepped upper cowl for fiberglass work by cleaning areas with acetone and adding more packing tape to lower cowl. Cut (3) 32″ strips of fiberglass for each side of the cowl at 1.25, 1.50, and 1.75 inches wide. Mixed small batches of West system epoxy (105 resin and 205 hardener) and saturated bottom strip before…

Continued to sand lower edge of upper cowling in preparation of lengthening the lower edge using hand and orbital sander with 60 grit. Finished rough sanding with 120 grit discs; should now be ready for fiberglass work. Cleaned upper edge of lower cowl with paint prep solution and applied packing tape to overlap area. Covered…

Began prepping upper cowl for fiberglass work by removing prop and spinner from engine then reinstalling lower cowl and cowl alignment spacer. Placed upper cowl into approximate position and secured to spacer. Traced 1.5″ line along upper cowl to mark limits of new fiberglass. Removed upper cowl and began to feather lower edge in preparation…

Continued to trim upper cowl to reach alignment with lower cowl. Removed lower cowl to clearance prop opening a little more. Used the bandfile belt sander for the last few passes which resulted in a slightly cleaner edge on the backside of the upper cowl. Once fit was close, reinstalled prop alignment hub and secured…