You may have noticed that up until now I have paid no attention at all to one of the most obvious “scale details” on the airplane…the windshields of the twin open cockpits. All too often open cockpit model windshields take the form of a chunk of clear plastic stuck to the top of the fuselage with a piece of trim tape or perhaps a glob of canopy glue. This model deserves better.
On the full scale airplane each of the two open cockpits has its own windshield, and each of them is basically identical to the other. Each consists of aluminum framing fitted with flat pieces of plexiglass cut to fit. In some cases these assemblies are riveted together, or they may be assembled (and attached to the fuselage deck) with machine screws and nuts. As I have done with other aspects of the “scale detail” of this little Great Lakes I’m going to devote some effort to replicating the appearance of the full scale structure without reproducing it component-by-component.
The first step in building a windshield “from scratch” is making a pattern. The kit plan provides one, but it is for a simple wrapped sheet of plastic and does not replicate the framed windshields I want on this model. Using the top and side views provided along with some photo references to full scale airplanes I decided what I wanted to make and created a pattern from thin cardboard. This required several stages of fitting-and-cutting to get it right.
This is another job for aluminum sheet. In this case I used a piece of .009" roof flashing. I traced two windshield blanks from the pattern onto the metal using a pencil.
As with the aluminum sheet side panels, I scored the windshield blanks with several strokes of a razor blade. It is not necessary to cut entirely through the metal.
Some careful twisting and bending will result in the blank breaking cleanly free of the rest of the sheet. Here I am getting ready to cut out the included openings, where the clear plastic will go. I have chose to drill small holes where the openings form tight angles to avoid having to score so aggessively that I risk cutting too far and destroying the blank.
Here is one blank as it came out of the parent sheet and the other drilled, cut and trimmed to final shape.
It will be necessary to make some sort of jig to permit bending the aluminum sheet on exactly the line you want it to follow. I used a couple of scraps of 1" x 2" fir and a clamp to do that job.
I drew locating marks onto the top deck, aligned each windshield frame in turn exactly where I wanted it, and stuck it in place with SLO- ZAP thick CA and a shot of ZIP KICKER, then I defined what will become the outside edge of the finished lower windshield frame with three layers of masking tape.
On the full scale airplane the lower edge of each windshield consists of a formed aluminum strip fastened over the lower edge of the plexiglass. My favorite way to replicate this is to define the outer edge with tape, as I did in the last step, and then fill the radius with a material I can sand to shape. In this case I am using ordinary clear dope and talc filler, mixed really thick. On a larger model I would be concerned about cracking, but on this little job the dope-and-talc fillet will be stable enough to rely on and really easy to sand to shape.
This is the windshield fairing fillet all built up, dry, and ready to shape.
What I am using here is in fact a custom made sanding block which happens to be round. I keep an assortment of scraps of tubing, dowels, and old bottles on hand to provide just the right radius for jobs like this. The three layers of masking tape define just the finshed thickness of fillet that I want to leave. I will sand the fillet down flush with the tape.
The outer panel of the windshield defines a different radius where it joins the fuselage side, so I used one of those old bottles to define the curve.
With the fillet material sanded to exactly the shape I wanted, I then peeled the multiple layers of masking tape away to form the simulated edge of a formed aluminum fairing.
Usually there are a few rough spots where the tape comes free. Here I am using the edge of a sheet of 320 grit paper to VERY CAREFULLY redefine the edge of my new windshield frame. The next time I work on this detail I'll be spraying it with primer. The clear plastic won't go in until after all the paintwork is done.