Airwaves

Model Airplane News, Jun 1999

Our readers write back

IT'S A ZIPPER

In your March 1999 issue, I kindly take exception to a caption in your story, "From Modeler to Test Pilot" (pages 46-50). On page 48, the top center photo is captioned "Comet Clipper." I believe this to be the wrong name of the model. The model is a "Comet Zipper," by Carl Goldberg. The "Clipper" was a cabin model; the one shown is a pylon model. I'm sure that you will receive some other letters about this.

I see that the winners of the Jo Kotula contest (page 18) were from the Midwest, save one from Maryland. Within 3 hours of receiving my issue, I dispatched my entry at the post office. I was wondering if perhaps there was a mailing schedule that might favor the middle part of America. I don't wish to appear a sore loser, but it does make me wonder.

KEVORK FAGS River-Vale, NJ

You're right that the caption misidentified Corky's beautiful Zipper as a Clipper. I suspect that 50 years of time caused Corky's memory to skip a beat. In fact, my guess is that he built it in 1939 rather than 1938, as he suggested, because production kits of the Zipper were not available in September 1938. A small error from a great man is readily accepted when handed up on the platter of fine remembrances that Corky shared with us.

But to set the record straight, you are correct: the Comet Clipper was a cabin ship. It was designed as a follow-up to Goldberg's Valkyrie (Goldberg's first pylon design), in an attempt to provide a design that was smaller and simpler than the Valkyrie.

The Zipper was a response to a change in competition rules. Prior to 1938, free-flight gas was run with a set of rules that limited aircraft to a fixed amount of fuel. This favored large, slow-climbing, gas-sipping models. In 1938, however, the rules changed, and aircraft were limited to a 30-second motor run. Carl Goldberg looked at these limitations and saw fastclimbing, high-powered, smaller models and designed what is now referred to as the "Diamond Zipper." This was actually the prototype (10 to 12 were built) for what would become the production Zipper, and those who flew them proved the Zipper to be the plane to beat during the 1938 season.

In 1939, commercial kits for the Zipper were produced, with modifications in response to lessons learned with the prototypes. The commercial kits had rounded fuselages and elliptical stabilizers. Corky Meyer's Zipper is clearly a production Zipper and, thus, had to have been built during or after 1939. The Zipper dominated the 1939 Nationals with several hundred of them entered in the event. Interestingly, Carl Goldberg wasn't among those flying the Zipper; he was looking forward and flying what would eventually become the Comet Interceptor.

The Zipper changed the face of powered free flight, and many similar designs were produced in the early '40s. Interestingly, it was the Zipper and its spinoffs that determined the December 1938 cutoff date for eligible designs for the SAM antique event. Without that rule, the Zippers would rule in that event just as they did in 1939.

As for "Midwest bias" in our mailing: all of our magazines are handed to the U.S. Postal Service in Tennessee within a 48-hour time window. I'm not sure how that would result in distribution biased toward the Midwest, but with the U.S.P.S., anything is possible, I suppose. It may be that getting a letter from New Jersey to Connecticut is the hard part. LM

OLD GLUES ARE STILL GOOD GLUES

In Gerry Yarrish's "Thinking Big" column (March 1999), the author only mentioned three types of glue for modeling. While reading the article about Mr. Corwin "Corky" Meyer going "From Modeler to Test Pilot," I saw that Mr. Meyer noted that his flight instructor helped him in his transition from "... Ambroid glue to afterburner blow-outs," and this prompted me to write about a fourth type of glue: the type that should be most endearing to us older modelers. I'm talking about the old standbys such as Ambroid, Sig-ment and Testors wood glue. I, for one, have never used anything else. As Mr. Meyer stated, his fingers "always had layers of glue on them"; my fingers are still that way. These old standbys are still vital to building models. They are very workable and are excellent in fusing balsa to balsa, balsa to spruce, and balsa to plywood. Let's not forget our roots, bless them all.

DAN OWEN

Klamath, CA

It has been said that you can always tell a real modeler, because he knows where to buy Ambroid. I still think there's merit to that statement. You're right that the cellulose glues have their virtues. But Gerry started his column with the statement, "The three most popular glue types ...; he didn't claim to list all the glues it's possible to use for building models. Rather, he stated a fact: that CAs, aliphatics and epoxies are used by the vast majority of modelers to form the vast majority of joints in modern model airplanes.

But many other glues are used in model building, including the cellulose-based glues. I often use the cellulose glues when I'm working on the exterior of a wood model; they sand better than anything else and leave no seams. I've built a lot of models in the past using only cellulose glues, but times change and glues improve, and I now use a variety of glues for every model I build. The glues Gerry talks about have become the staples of the modeling community because they do their jobs very well. WRITE TO US! we welcome your comments and sugestions. Letters should be addressed to "Airwaves," MODEL AIRPLANE NEWS, 100 East Ridge, Ridgefield, CT 06877- USA; email man@alrage.com. Letters may be edited for clarity and brevity. We regret that, owing to the tremendous numbers of letters we receive, we can not respond to every one.