This article was originally published in Fly RC’s April 2016 issue.
By Tim Bailiff
At the risk of sounding too cliché, getting older really does make you wiser. Honestly, it’s a matter of experience. Over the years I have made so many mistakes and wasted so much time and money that I was finally forced to find solutions to my modeling concerns. Now, while much of what follows is what I personally discovered, I would be remiss if I didn’t say that some was shared with me by friends and fellow modelers. Thankfully most of those creative modelers are still with us, but sadly some of them have moved on. I felt, by sharing these tidbits of wisdom, a part of their knowledge would live on.
I realize that what I am sharing may not exactly rock your world, but these tips certainly have improved my modeling world. Besides, I’m sure there are a great many novices who regularly peruse these pages. Individually some of these ideas have been tremendously helpful, while other others have only helped slightly. Yet, when taken as a whole, they have made a huge difference in the amount of pleasure and enjoyment I get from building and flying my radio control aircraft. Hopefully the same will be true for you. Even if you only find one thing that helps … Hey, it helped, right?
In my opinion, one of the most time saving developments in aero modeling has been in the field of adhesives, specifically Cyanoacrylate glues, also called CA. As a kid, glues such as Ambroid, Titebond and Elmer’s Glue were the main choices. The problem was they took so darn long to dry. I’d build a little, and then have to wait overnight for the glue to dry. OMG! My projects seemed to take forever to finish, but then, CA was introduced. What a difference this “super glue” made for me! It was like a miracle. My model planes seemed to fly together (pun intended). That being said, I soon found that CA had its own set of problems to overcome.
Aside from the frequent “fingers being glued together or to the plane”, the biggest drawback for me was that it always dried out. No matter how careful I was, it would eventually evaporate. My CA would gradually get thicker and thicker until it wasn’t usable any more. Generally, that unusable moment came right in the middle of a project and late at night. You’ve been there, right?
One day, while at my local hobby store, a friend offered this simple suggestion. Just store it in the refrigerator. I followed his advice and from that day forward all of my CA stayed perfect. Even after a year or more, a partially used bottle of glue remains the same. Thin CA stays thin; medium stays medium and thick stays thick. Problem solved!
One last suggestion … set your bottles of CA in a plastic container. I decided early on it would be best to avoid explaining to the wife why the refrigerator wouldn’t open. The plastic container doesn’t even need a lid, but should a bottle ever crack or tip over, you are covered.
Since I have just discussed CA, allow me to discuss “Kicker” as well. You all know that Kicker is the catalyst that “sets off” CA and makes it harden instantly, if not quicker! Well, I have found a few tricks you may wish to add to your personal bag of tricks.
How many times have you wanted to use CA to secure a keeper holding on a wheel? You know the drill. You slide your wheel onto the axle, place the keeper and then you make sure it spins freely. Let’s also say you have decided to use a small washer or a thin slice of tubing as a keeper to hold the wheel on. You decide to use just a touch of CA to hold your keeper in place. You gently touch the tip of your bottle to the outside of your keeper and immediately realize something has happened. Something bad! Yep, your wheel won’t turn and is, in fact, cemented to your axle. Seriously?
So what actually just happened? Well, CA has the ability to wick into porous structures and run along impermeable surfaces. Now if you are trying to cement wood together, excellent, but if you’re trying to secure a keeper in place and want that small touch of CA to stay put, not so good. It just traveled along the axle past your keeper and into your wheel as well. So, here is the fix that worked for me. If you wet the tip of the axel with Kicker before applying the CA, it will set up almost instantly. That means it won’t have time to run along the axel, but will stay put and securely glue the keeper in place.
Now, here’s another way you can benefit from using kicker to capitalize on CA’s wicking characteristic. When dealing with balsa, there are times when a little more strength is needed in a particular area. Instead of adding ply or hard wood, simply spread a little “thin” CA around the area and allow it too absorb (wick) into the balsa for a moment. Then, apply some kicker to a paper towel and quickly wipe over the surface of the CA saturated balsa. Be sure not to hesitate while doing this. The CA will quickly harden and strengthen the balsa greatly, without the need for any additional hard wood. I use this technique a lot when building my RC planes. This works especially well for mounting small electric motors and servos.
Now this is some pretty cool stuff. For those unfamiliar with it, Bluecor is actually construction grade underlayment foam board made by DOW. It is 1/4-inch thick, folded extruded polystyrene board with plastic film on both sides. The plastic film is bonded to the foam using heat, not glue. This makes for a nice light, yet stiff piece of foam that’s very easy to work with. It reminds me of very light balsa.
Ready for this? It’s sold in 50-foot lengths! That’s right. Each piece is four feet wide, 50 feet long and then fan folded every two feet. This is why it’s commonly referred to as “fanfold”. You may be thinking, “Yikes, how am I going to store that much material”?
Well, I know it sounds like it would be a huge stack of foam, but it’s surprisingly compact and manageable. A folded bundle is 2×4 feet and only about 10 inches thick. That’s actually not hard to store along a wall in your workshop or garage. My bundle is standing alongside a refrigerator in my garage. It’s out of the way, yet easily accessible.
OK, I know what many of you are thinking. What modeler needs 200 square feet of ¼-inch foam, right? Well the answer is, one modeler may not need that much, but several would! That’s precisely what I did the last time I purchased a bundle. I bought a bundle and then split the cost and foam with several other flying buddies. Finally, I’ve saved the best for last, the price. Although I’m sure prices will vary, I bought my Bluecor bundle for $50. That’s only $2.00 for each 2×4-foot section. Have you seen the price of hobby foam lately? What a bargain this is!
Now in all fairness to some foam products like Depron, I must say that Bluecore is not quite as durable. Bluecore will crush and even break. However, with a little tape strategically placed in the middle and around the edges (to be discussed next), it is a great material for aero modeling use. Obviously a minimum of crashes would be best, however, if a spot does get crunched, it’s very easy to do a little surgery and replace the affected area. It really is great to work with and makes for creating some really nice flying foamies.
It didn’t take me long to figure out that packing tape could be used to adorn and strengthen my foam planes. Two-inch rolls are available in almost any color imaginable online. At first I had a little problem handling it, especially when dealing with intricate designs. Then I learned a little trick. If you first stick your colored tape to wax paper, you can then cut and trim it as you please. After you finish with your design, the wax paper backing can be easily peeled off and the tape can be treated like any other sticker. Try it, it really works great.
Another thing I found is that packaging tape can make a dramatic difference in the strength of foam planes. Every place that tape is applied becomes stronger. One location I discovered took care of the problem related to wing spars. For many flyers, their planes tend to fly the majority of the time upright with a positive wing loading. Especially on smaller foam wing planes, a single length of tape applied tip to tip on the underside of the wing, at the center of gravity, will act as a spar. That means the added weight of an additional wooden or carbon fiber spar becomes unnecessary. I have used this method in numerous designs with great success. Give it a try.
Fiber reinforced packaging tape adds even more strength to foam designs. Depending on the brand, this tape may also be called strapping or shipping tape. Scotch Brand “Extreme” shipping tape, a 3M product, is one variety I have found to be excellent for my modeling needs. With reinforcing fibers running along its width as well as length, this tape is hard to beat. As discussed earlier, when applied to a spar, it will add an incredible amount of strength and rigidity to any wing. When applied to leading edges and wing tips, it helps guard against the ever present “hangar rash” that plagues all of our planes.
Not to be forgotten, remember your fuselage as well. When placed along the length of your fuselage, especially around your motor mount, it will add a tremendous amount of rigidity and strength. Don’t hesitate to use the colored tape here, too. You will be adding good looks and reinforcement all at the same time. Hey, it’s a win-win situation!
Yet another tape produced by 3M is Blenderm Surgical Tape. While specifically made for the medical industry, this is undoubtedly my favorite modeling tape. What makes it so special is that it is very flexible, really light and extremely strong. It sticks like crazy because it is designed to stay stuck to nasty, sweaty skin while providing a waterproof barrier.
Whether your plane is made of foam or balsa, this is the ideal tape for making hinges. After its application, its transparent flat finish makes it virtually invisible. I usually buy one-inch wide rolls, but it does come in half-inch and two-inch rolls as well. That being said, should you need a very narrow hinge, it can easily be cut and will still provide great flexibility and adhesion. Because of its waterproof qualities, it stays stuck and flexible in otherwise harsh flying conditions. Should you be aloft when it begins to mist or rain, rest assured, your hinges will stay attached. Also, should you happen to land in wet grass, no worries as Blenderm won’t be affected in the least.
I personally buy it by the box and have used it for many years. Without exception, all of the hinges I’ve made are still flexible, secure and going strong. From 10-inch planes to five-foot planes, Blenderm has proven to be a terrific material to work with. Du-Bro actually sells a tape similar to Blenderm.
Hopefully I have presented some ideas that you will find useful. I should add that there may be several brands for some of the prod- ucts I’ve mentioned. All are good, but some are better. Only your own experience will tell you which ones work best for you. Don’t be afraid to try something different. There are many materials that can easily cross over and be used in our world of model aviation. Keep your mind open to change. Dare to be unique. Remember that with age comes experience, which leads to wisdom. Happy modeling my friends. Fun stuff.