Genesee Valley Aero Modelers

Editor: Glenn Crocker
21 Highview Trail
Pittsford, NY 14534

Happy landings,

The GVAM Family Picnic has come and gone. The weather was excellent. The wind could have been a little lower but it wasn’t bad.

We had approximately 30 people at the picnic (even Grumpy made an appearance) and they all brought an appetite. Ned’s beans with his super secret seasoning went over very well and all that was left was an empty pan. Dave took this year off from his cooking duties (sore leg) so it was up to Crocker to burn the dogs and hamburgers.

Wendell and Carol Coye were able to attend and we were glad to see them.

The field has been kept in great shape this year by the mowing volunteers. Extra credit has to go to Charlie for his rolling of the field. It seems after every rain he has gone up and used the roller. Sometimes when it rained in the morning and afternoon the field got rolled twice. This has reduced the size of the launching mound that is about halfway down the long runway.

Remember this month the club meetings will start again. I would like to propose that we have Ladies Night Out on October 12^th this year. We sure attracted a crowd last year when we moved the date. Think about it and we can discuss it at the meeting.

Remember watch for the plane eating trees (and Walt), enjoy your flying and keep the wheels on the bottom.

If interested, contact Robert Hager 585-346-2798.

I hope you had a chance to attend the Interclub Picnic. These events are a good chance to meet flyers other than our own club members and see other types of aircraft. This year we turned it into a five club gathering and extended an invitation to the Chiefs to join us.

The weather was almost perfect. Temperature was in the 70s. The wind was a little high but it was coming right down the runway. We had 35-40 attendees and plenty of food to go around. There was a lot of flying with only one mishap.

There was a large P51 (a Byron I think) flying when an older gentleman (not associated with the picnic) stopped by to ask directions. It turns out he was a crew chief for a P51 in WWII and just could not stop talking about how realistic it looked and what memories it brought back. He said it was the first one he saw in the air since the War. I don’t know who owned the plane but it sure made this gentleman’s day.

There was even a Kangaroo with a turbine on static display. He fired it up in the morning and it sure sounded good. The whole starting sequence was automatic with one push of the button on the Transmitter. New toys for Nowakowski!?

There were electrics, a ducted fan, a helicopter, military, sport and some really weird looking planes that flew like stink.

The weather cooperated, the planes cooperated and everyone had a great time.

During a cross country flight in my old Cub, I began looking for an airport where I could refuel. As my fuel condition worsened, I added gas stations with suitable landing areas to my search list. As the fuel level reached the critical stage, my search narrowed to any darn gas pump I thought I could get to!

Finally, I spotted such a station, right alongside a straight highway with remarkably few obstacles.

As I taxied up to the pumps I wondered how the old man in the rocking chair near the doorway was going to react to an airplane customer. When he seemed totally unaffected by it, I finally had to ask, "I don’t suppose you get many airplanes here at your station, do you?"

If you have ever had the problem of a prop nut coming loose inside a spinner, you will want to listen up. One thing you can do that works well is use a jam nut. This is nothing more than another prop nut tightened up against the first one you put on. It locks the first nut in place and keeps your prop from working loose. One thing to keep in mind is that if you are using a wood prop, the wood will compress over time and both nuts will need to be tightened. Do this one at a time getting the nut closest to the prop tight first and then tighten the other nut while holding the first in place.

Model airplanes are no different from any other type of flying machine, large or small. The lighter it is built, the better it will fly! with that in mind, it is easy to understand why balsa wood has been the standard material for model airplane construction since it first became readily available in the US in the late 1920s. Its outstanding strength-to-weight ratio enables hobbyists to construct durable models that fly in totally realistic manner. Balsa also absorbs shock and vibration well and can be easily cut, shaped, and glued with simple hand tools.

Where does balsa wood come from? Balsa trees grow naturally in the humid rain forests of Central and South America. Its natural range extends south from Guatemala, through Central America, to the north and west coast of South America as far as Bolivia, however, the small country of Ecuador on the western coast of South America is the primary source of model aircraft grade balsa in the world. Balsa needs a warm climate with plenty of rainfall and good drainage. For that reason, the best stands of balsa usually appear on the high ground between tropical rivers. Ecuador has the ideal geography and climate for growing balsa trees. The scientific name for balsa wood is ochroma lagopus. The word balsa itself is Spanish meaning raft, in reference to its excellent flotation qualities. In Ecuador it is known as Boya, meaning buoy

How does balsa wood grow?

There is no such thing as entire forests of balsa trees. They grow singularly or in very small, widely scattered groups in the jungle. For hundreds of years, balsa was actually considered a weed tree. They reproduce by growing hundreds of long seed pods, which eventually open up and, with the help of the wind, scatter thousands of new seeds over a large area of the jungle. Each seed is airborne on its own small wisp of down, similar to the way dandelion seeds spread. The seeds eventually fall to the ground and are covered by the litter of the jungle. There they lay and accumulate until one day there is an opening in the jungle canopy large enough for the sun's rays to strike the jungle floor and start the seeds growing. Wherever there is an opening, made either by a farmer or by another tree dying, balsa will spring up as thick as grass. A farmer is often hard put to keep his food plot clear of balsa. As the new balsa trees grow, the strongest will dominate and the weaker trees will die. By the time they mature, there may be only one or two balsa trees to an acre of jungle.

How long does it take a balsa tree to grow? Balsa trees grow very rapidly (like all pesky trees). Six months after germination, the tree is about I 1/2 inches in diameter and 10 to 12 feet tall! In 6 to 10 years, the tree is ready for cutting, having reached a height of 60 to 90 feet tall and a diameter of 12 to 45 inches. If left to continue growing, the new wood grown on the outside layers becomes very hard and the tree begins to rot in the center. Unharvested, a balsa tree may grow to a diameter of six feet or more, but very little usable lumber can be obtained from a tree of this size.

The balsa leaf is similar in shape to a grape leaf, only a lot bigger. When the tree is young, these leaves measure as much as four feet across. They become progressively smaller as the tree grows older, until they are about 8 to 10 inches across. Balsa is one of the few trees in the jungle which has a simple leaf shape. This fact alone makes the balsa tree stand out in the jungle.

How are balsa trees harvested? While nature intended the balsa tree to be a short-lived nursemaid, humans eventually discovered that it was an extremely useful resource. The real start of the balsa business was during WW I, when the allies were in need of a plentiful substitute for cork.

The only drawback to using balsa was, and still is, the back-breaking work that is necessary to get it out of the jungle. Because of the way the individual balsa trees are scattered throughout the jungles, it has never been possible to use mass production logging procedures and equipment. The best way to log balsa trees is to go back to the methods of Paul Bunyan-chop them down with an axe, haul them to the nearest river by ox team, tie them together into rafts, and then float the raft of balsa logs down the river to the saw mill.

The logging team usually consists of two native Ecuadorians, each armed with a broad Spanish axe, a machete, and a long pole sharpened like a chisel on one end for removing the bark from the downed trees. Because of the hilly terrain, an ox team may only be able to drag two logs to the river per day. At the saw mill, the balsa is first rough cut into large boards, then carefully kiln dried, and finally packed into bales for shipment to the US via ocean freighter.

The secret to balsa wood's lightness can only be seen with a microscope. The cells are big and very thinned walled, so that the ratio of solid matter to open space is as small as possible. Most woods have gobs of heavy; plastic-like cement, called lignin, holding the cells together. In balsa, lignin is at a minimum. Only about 40% of the volume of a piece of balsa is solid substance.

To give a balsa tree the strength it needs to stand in the jungle, nature pumps each balsa cell full of water until they become rigid-like a car tire full of air. Green balsa wood typically contains five times as much water by weight as it has actual wood substance, compared to most hardwoods which contain very little water in relation to wood substance. Green balsa wood must therefore be carefully kiln dried to remove most of the water before it can be sold. Kiln drying is a tedious two week process that carefully removes the excess water until the moisture content is only 6%.

How light is kiln-dried balsa wood? Finished balsa wood, often found in model airplane kits, varies widely in weight. Balsa is occasionally found weighing as little as four pounds per cubic foot. On the other hand, you can also find balsa which can weigh 24 pounds or more per cubic foot. However, the general run of commercial balsa for model airplanes will weigh between 6 to 18 pounds per cubic foot. 8- to 12-pound balsa is considered medium or average weight, and is the most plentiful. Six pounds or less is considered "contest grade," which is very rare and sometimes even impossible to obtain.

Is balsa the lightest wood in the world? No! Most people are surprised to hear that botanically, balsa wood is only about the third or fourth lightest wood in the world. However, all the woods which are lighter than balsa are terribly weak and unsuitable for any practical use.

The very lightest varieties don't really resemble wood at all, as we commonly think of it, but are more like a tree-like vegetable that grows in rings, similar in texture to an onion. It is not until balsa that there is any sign of real strength combined with lightness. In fact, balsa wood is often considered the strongest wood for its weight in the world. Pound for pound it is stronger in some respects than pine, hickory, or even oak.

From RCPropwash Ocala Flying Model Club
Dick Smith, editor Ocala FL

Rit Cloth Dye, available in most supermarkets, fabric stores, or drug stores, will tint the clear plastic quite well. Mix up the dye in lukewarm water in a container large enough to immerse the entire canopy. Dip the canopy for a period of one minute or so, until you get the feel of how fast the dye is "taking." Rinse in cool water and dry off. If it is not dark enough, dip it again. You can even be tricky about the tint by making a fixture to hold only a certain part of the canopy in the dye. The effects you get are only limited by your imagination.