I?m building an RV-14 and never realized that there was so much fiberglass work to be done.
The wheel pants are constructed from two shells, which must be mated to each other and then cut out to accommodate the tires and gear legs. This means attach, measure, trim, sand and repeat at least five times. Fiberglass parts are attached with countersunk screws, which must be match drilled; deburred and countersunk. Airfoils are fabricated for each of the gear legs and then fitted with transitional fairings between the pants and the fuselage. Each of the airfoils (horizontal stabilizer, vertical stabilizer, elevators, rudder & wings) have tips that also are fabricated from fiberglass. That?s more attach, measure, trim, sand and repeat at least five times.
And then all seams, the canopy & tail feathers are contoured to the fuselage with micro-ballon/epoxy fillers followed by fiberglass layups (each step accompanied by much sanding - over and over again) to form the smooth contoured junctions that promote drag reducing laminar flow.
The work is tedious and uncomfortable despite wearing particulate masks and protective clothing. The fiberglass dust gets everywhere; everyone has hangar cough and itchy skin. I have spent at least four full-time weeks working on the fiberglass. I never realized that an aluminum RV has so much fiberglass work to do. I suspect there is actually more fiberglass work on this aluminum airplane than would be done on a composite airplane kit, as all these parts are incorporated into the original's mold.
Fiberglass fittings & fairings are often attached to a plane with counter sunk flat head screws. But fiberglass is soft compared to metal, which will erode and enlarge the countersunk holes when stress is applied during flight. Brand name Tinnerman countersunk washers spread the force and lessen the wear, but are made from Zinc coated spring steel. Aircraft Spruce sells CSK washers, which are knockoffs, made from stainless steel and are cheaper.
I?m building an RV-14A and can report that the CSK washers fit the fiberglass countersunk holes and 100? flat head screws perfectly (countersink only enough to fit the screw) and are low profile ? so shouldn?t cause too much drag. I haven?t attempted to countersink the whole washer, which would weaken the fiberglass.
The wheel pants are constructed from two shells, which must be mated to each other and then cut out to accommodate the tires and gear legs. This means attach, measure, trim, sand and repeat at least five times. Fiberglass parts are attached with countersunk screws, which must be match drilled; deburred and countersunk. Airfoils are fabricated for each of the gear legs and then fitted with transitional fairings between the pants and the fuselage. Each of the airfoils (horizontal stabilizer, vertical stabilizer, elevators, rudder & wings) have tips that also are fabricated from fiberglass. That?s more attach, measure, trim, sand and repeat at least five times.
And then all seams, the canopy & tail feathers are contoured to the fuselage with micro-ballon/epoxy fillers followed by fiberglass layups (each step accompanied by much sanding - over and over again) to form the smooth contoured junctions that promote drag reducing laminar flow.
The work is tedious and uncomfortable despite wearing particulate masks and protective clothing. The fiberglass dust gets everywhere; everyone has hangar cough and itchy skin. I have spent at least four full-time weeks working on the fiberglass. I never realized that an aluminum RV has so much fiberglass work to do. I suspect there is actually more fiberglass work on this aluminum airplane than would be done on a composite airplane kit, as all these parts are incorporated into the original's mold.
Fiberglass fittings & fairings are often attached to a plane with counter sunk flat head screws. But fiberglass is soft compared to metal, which will erode and enlarge the countersunk holes when stress is applied during flight. Brand name Tinnerman countersunk washers spread the force and lessen the wear, but are made from Zinc coated spring steel. Aircraft Spruce sells CSK washers, which are knockoffs, made from stainless steel and are cheaper.
I?m building an RV-14A and can report that the CSK washers fit the fiberglass countersunk holes and 100? flat head screws perfectly (countersink only enough to fit the screw) and are low profile ? so shouldn?t cause too much drag. I haven?t attempted to countersink the whole washer, which would weaken the fiberglass.