SNB-P13: Cowling
Cowl Fiberglass Work – Part 6
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.…
Cowl Fiberglass Work – Part 5
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…
Cowl Fiberglass Work – Part 4
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…
Cowl Fiberglass Work – Part 3
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…
Cowl Fiberglass Work – Part 2
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…
Cowl Fiberglass Work – Part 1
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…
Cowl Fitment – Part 7
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…
Cowl Fitment – Part 6
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…
Cowl Fitment – Part 5
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…
Cowl Fitment – Part 4
Began fitting upper cowl by placing onto lower cowl and notating baffling interference. Trimmed front of baffles by about half an inch and rechecked clearances. Made the determination that tucking upper cowl under the windshield skirt will likely make removing the upper cowl difficult with prop in place. Began process of making a shelf for…
Cowl Fitment – Part 3
Aligned the cowl into its final place then pilot drilled side hinges to cowl. Initially only pilot drilled a few holes due to space constraints. Pilot drilled a few holes in the bottom cowl hinge half by using flashlight method to locate holes through the fiberglass. Removed cowl and hinges from the airframe then finished…
Cowl Fitment – Part 2
Decided to solve oil cooler clearance issue by moving oil cooler up by about 5/8″. Removed oil cooler bracket from bottom of engine and remade bracket from 1.5″ x 1.5″ aluminum angle stock with shorter leg. Installed new bracket on bottom of engine with Loctite 242 then reinstalled oil cooler to new bracket. Reinstalled lower…
