You’re absolutely right, of course, and I’m surprised there are still people who don’t know that. Some will call us The Spelling Police, but they’re the people who still refer to “glidescopes” and show their knowledge of French by using the word “walla.”

Im just saying that the generalised term ” epoxy ” is perhaps a bit misleading , and nobody would use it ( whichever sort they chose ) for aircraft use without being satisfied that it was suitable for the application .

What epoxy I did us in my Falco, for nonstructural applications, was West Systems. Hardly a “five-minute epoxy,” and I’m amused that you would think anybody spending about$150,000 (in today’s dollars) to build a Falco would be dumb enough to buy hardware-store glue.

When I write of epoxy in aircraft applications, you can safely assume I mean epoxy “suitable for the application.” Which I guess would make it suitable for, uh, motorcycle handgrips, which apparently is your area of expertise.

As a footnote, Annex K, on my reading, makes no mention of wood rot.

I was simply guessing that it was wood rot, but my ultimate point, which remains valid, is that it didn’t matter what color you painted the airplane. The glue did not weaken with heat, as does epoxy.

Mossie’s didn’t fall apart in Northern Europe – but they did in the tropics.

Assumedly from wood rot caused by the high humidity. Wouldn’t matter what color you painted them.

At least I now know far more about glue than I ever realised I needed to know, and much more than I ever knew there was to know.

In fact there have been substantial volumes written about aircraft glue. One of them, published by the U.S. FAA, is essential reading for those of us who build wooden airplanes. Whatever you now know about glue after reading this thread is little more than the proper spelling of formaldehyde…

Re paint, ours in Egypt were wearing normal camouflage for the period of light sea grey dark green. We were rumoured to run cockpit temperatures up to 160 F at low level, so it was us who melted, not the glue.
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Mosquitos weren’t built using epoxy glue, so nobody has said they were subject to glue-weakening due to heat buildup. They weren’t and could be painted flat black, for all that it mattered.

“Jap planes”? (In the thread title.) How about a thread on Guinea planes,or maybe Spic planes?

Bruce writes that the glues used present day are ‘derived’ from the original glues. That implies that they are the same glues but possibly different! Are they the animal derived glues I’ve referred to or formaldehyde based? I believe that both were originally used.

In the 1990s, I built a Falco F8L using Aerolite, which at the time, at least, was a two-part urea/formaldehyde glue. We were always told that it was “the same glue that had been used in Mosquitos.” Some Falco builders used modern epoxy glues, but this required them to paint their Falcos white, since heating from sun-soak could seriously weaken “modern” epoxies, and dark colors of course exacerbated this; it’s the reason all modern sailplanes are, without exception, white. Attaining an internal temp of 180 degrees F. was common on an airplane sitting on a concrete ramp in, say, Phoenix, Arizona.

Kit- and plans-built Falcos have never had any problem with moisture, since every builder carefully encapsulated the interior of the entire structure in modern, two-part epoxy “varnish,” which made them impervious to water. One factory-built Falco I flew before building mine had spent several years sitting outside on an airport in Ireland, its canopy broken and the cockpit half-awash in water.

A good homebuilt Falco will also have effective drainholes at the low point of every fuselage and wing bay.

My Falco is currently in Australia, on its second owner, and I’m guessing it probably has at least 1,000 hours on the airframe (I put on 400) and is about 20 years old. It was -flown- to Australia from Portland, Oregon via the Atlantic, Europe, North Africa, the Middle East, India, the Malay Peninsula, PNG and across all Australia to Melbourne. The professional ferry pilot who made the trip later told me the engine “never missed a beat,” which pleased me since I’d overhauled it myself in the basement workshop of our rural New York home.

Anybody who wants to know anything about wood aircraft construction and glues should contact Alfred Scott at Sequoia Aircraft, suppliers of the Falco kits (seqair.com). My friend Alfred knows more, I dare say, about wooden airplanes than anybody this side of Geoffrey de Havilland.