The success of flying a plane hinges upon correctly installing the control surfaces. Most ARF’s now come with the popular Mylar flexible hinges. These hinges are very good for their intended task. They are strong and light. The hinge points do not get gummed-up with the installation glue. They do, however, require some care in their installation. If you are assembling a Trainer-type ARF the chances are that you are new to the hobby. The instructions usually simply state, “Glue hinges in place”. Almost all directions assume that you know how to handle super-glue. What follows are a few tips that will help ensure that you do not experience loose hinges or control failure during flight that could lead to less than desirable results.
The working concept of a Mylar hinge is that a coating of absorbent fiber is adhered to both surfaces of flexible Mylar. The hinge is inserted in both parts and then glued while still in that position. The coating is designed to readily accept thin CA adhesive. It will “wick” the glue over its entire surface and into all of the adjacent material, such as balsa wood. The advantage of the Mylar hinge is that all of the hinges can be put in place and then the glue applied. Mylar hinges are also extremely durable.
The Mylar hinges are intended to be used only with a specific type of glue. This glue is known as thin CA, sometimes called Cyanoacrylate and often called “Super-Glue”. If there is no glue supplied with the model, you need to select the right type. The thing to look for is the word “thin”. The glue comes in thick, medium and thin designations. It may also say slow, medium or fast on the bottle, with some indication of how many seconds it will take to bond. “Thin” usually cures in 5-10 seconds and is the glue that you want. There is also a new flex-thin CA that is specifically designed for the Mylar hinging process, from Bob Smith Industries.
This type of glue sets very quickly. It is often referred to as instant glue. It definitely sticks your fingers to things, or your fingers to your fingers, instantly! It is a very good idea to keep a brand name CA solvent handy at all times. Acetone also works very well with freshly-used CA. It comes in quart or gallon cans and can be purchased at your local hardware store. Try not to wipe with paper towels because the glue will come right through the towel and glue your finger as if it were applied directly.
|
