Dave, thank you for sharing us with this information. This is the first mention I have heard from anyone that they thought Doculam might be an inferior covering material. especially on open bays or frames.
What mil is the Doculam you were having trouble with?
Here are a cople of pics of planes covered with Doculam.
Robert
Control line combat guys have been using clear mylar lamination film for a long time now.
I have either 1 or 1.5 mil right now. There are no issues, it just provides very little strength in tension compared to silkspan, monokote or the thicker Mylars. But you may not need it. No way I would even think of using it on large open bays in control line, or a 10 foot glider for that matter.
Some of the wing designs especially in controlline require some stiffness in the covering for structural integrity.
The lightly loaded electric planes you have shown will not have an issue. Most of the stiffness is in the structure the speeds are slow and the air loads are light. It is great for that application.
A control line combat (80-100mph) or stunt model may pull over 20g in a tight corner. The mylar used on an F2d airplane is much tougher than 1.5mil douclam for reason. The loads on a controlliner can be very high!
So it is good stuff, just use it for the proper application. It works great on foam, or sheet surfaces, and smaller ligher craft. Thicker or stronger formulations work just fine with all the advantages you listed. Just understand its limitations and the requirements.
Get a sample of the SLC covering and you will be impressed by how tough it is.
Dave