RE Covering of Wing

 Some tips gleaned from a telephone conversation with Julius Junge on October 4, 2002

Julius said that he used a generic dacron purchased from Aircraft Spruce and it worked very well. They have three weights, from 1.8 to 2.5 and 3.5 and Julius used the 1.8 pound per square yard weight for Don Campbell’s Bleriot. He installed the material on the bias for greater flexibility and strength. Price was about $3.50 (

US

) per yard. The covering does not wrinkle when the wing warps because it is installed on the bias. The diagonal seams were simply lapped (not French fell seam) with a tape above, and double stitched. Tapes were also applied along the leading and trailing edge seams.

 

The material was held to the wing ribs with a nitro-cellulose lacquer from Home Depot at $17.00 (US) a gallon.

 

Before application, Julius left a jar of this lacquer overnight uncovered, so the lacquer thickened then he gave a coat to the rib and let it dry for a day. Then one coat (unthickened) was applied before the fabric was placed on the wing, and this allowed ample time to place the fabric before the lacquer set. With this done, and the fabric in place, then dip a finger in the lacquer and apply a single coat of lacquer along the seam to finish.

 

The next step is to purchase a bundle of reed, Julius got his from California Canery, but we can probably locate a source from the Montreal Association for the Blind, who must use it for weaving chair bottoms.

 

The reed comes from Malaysia, and is split into parallel strips of varying width; Julius used reed one-quarter inch wide. This is the material Cole Palen used on the Bleriot (c/n 56) we saw at Old Rhinebeck. Before use, soak the reed for an hour and it becomes as flexible as spaghetti (says Julius). The strips are applied above and below each rib, and nailed in place. Julius found it best to pre-drill the holes to prevent splitting. Hayward recommends placement of nails every two inches on the upper surface, and every inch on the lower surface. Julius used 20-gauge steel nails, plated, of course, but we will use copper or brass nails as recommended by Hayward.

 

It is not clear from the photograph (Hayward) whether the seams run spanwise or chordwise. This is still to be determined, but the text seems to suggest the former.

 

Julius says he sealed the wing surfaces with a single coat of this nitro cellulose lacquer, and said it worked much better than Super Seam. He then painted the surface with a furniture stain, brushed on, to give an attractive, slightly streaky appearance. He then sprayed on two coats of butyrate dope. The result was good, giving the wing a translucent effect and showing the structure within.

 

We will have to establish the correct bias angle to avoid rippling.

 

The first coat of a lacquer must be applied sparingly. Julius said he had no idea of the tautening characteristics of the lacquer, but it worked well.

 

Julius noted that the French originally sealed the wing surfaces with linseed oil, so it must have got impregnated with dust in time, they also used silk or balloon fabric.

 

Above describes the Bleriot Julius built for Don Campbell (of Broadbent, Wisconsin), the second Bleriot he built. The first was for Roger Freeman, who did the covering himself, and he applied about eight coats of dope to the wings, which reduced the flexibility, and resulted in a frightening lack of lateral stability.

 

We discussed the tailwheel, and Julius said he installed a tail skid on DC’s Bleriot, based on drawing he had seen of the skid on a Bleriot XI-2 (the tandem 2-seater). This skid is shaped rather like a hockey stick, raked backwards. Then Julius made it steerable and he said one could drive it like a car, instead of the fearful ground handline characteristics of a standard Bleriot. We have photographs of the Shuttleworth Bleriot (built by Humber in England), and it had a sort of yoke on the upper end of the member carrying the castoring tailwheel. Bungees were attached to this yoke, but it could well be linked to the rudder bars. This would be very useful if we expect to fly from a narrow runway such as St. Lazare. (We have not yet selected a location for our first flight tests.)

 

We briefly discussed rolling circular tube to an oval shape. Julius has heard of a company that makes oval boiler tube in wall thickness of .025, .035, .049 and .063 inches, using 1025 material which Julius much prefers to the 4130. He says even 1025 is much better than any tube available in 1910.  

 

He says he purchased some 1,600 pounds of AN parts for $50 (US), and has lots of turnbuckles,(¼" thread) available at a good price.  

 

Julius has an email address, Julius@stic.net I gave him my email as: patrickcampbell@cahc-ccpa.com  

 

Julius said the man who flew DC’s Bleriot so successfully is Didier Esteyne. I did not have the surname. Julius also recommended that we contact Paul Poberezny of the Sport Aviation Association at ... www.sportaviation.org

 

 

 

Patrick Campbell, Director of Manufacturing, CAHC