|Building the Cowl for the L-4, J-Kota, Inspirer
Biplane and Flybaby Biplane
Dremmel Rotary tool with Large and Small Sanding Drums
Small Paint Brush (#2 or so)
Sharp scissors - preferably the curved type
220 grit wet/dry sandpaper
Liquid Weld Cement for styrene plastics
Medium Gap Filling Cya or 5 Minute Epoxy
Primer and paint of choice
|I prefer using Liquid Weld Cement for plastics as it gives a
better joint, and won't leave the plastic brittle like Cya. There
are several brands available that will work well. Check the
plastic model section of your hobby shop and use what they
|The Cowl Kit comes on 3 Vac-Formed sheets, and includes
the Cowl, dummy Continental A-65 engine cylinders,
cylinder mount cavities, valve covers, and cooling baffles
|Begin by cutting the Cowl from the backing sheet 1/16" above
the excess plastic. Then open up the indented areas on both
sides to accept the cylinder assemblies. Then the prop
opening and oil cooler slot can be trimmed open. You can open
up the carburetor air box inlet too, but that's up to you.
|Trim the Upper and Lower Cylinder halves from the carrier sheet leaving 1/8" or so
of excess material around the perimeter. Then glue the halves together. When the
glue has dried, cut the bottom off as shown and fill the concave seams on the inside
with either 5 minute epoxy or medium Cya and allow to dry thoroughly.
|The dummy cylinder mount cavities are cut out next. Note that they are marked L and
R. Align them with the cutouts, on the inside of the cowl, and glue them in place.
|Cut the Valve Covers and Eyebrows from the carrier sheet
and sand the edges nice and smooth. Leave a 3/32" or so
wide lip at the top of the eyebrows as shown. Also leave a
fair amount of material at the bottom so that the fit can be
trimmed in nicely to the cylinders once they're installed into
their mount cavities.
|Once the glue has dried thoroughly, trim and sand the
excess plastic from around the cylinders. Fill any remaining
gaps with glue and sand.
At this point the parts are assembled, sanded, and ready to
paint. Go to for all the Details
|Once the Cylinder Assemblies are trimmed and sanded, fit
them into the cowl. You might need to trim the openings a bit
to slip them in, but work slowly so you get a nice snug fit.
Align the Cylinder banks so that they are nice and straight
when viewed from the top and front. If they're "cockeyed",
they'll ruin the look of the whole model -- plus, you'll have a
heck of a time trying to get the Eyebrows aligned during final