SO YOU, WANT TO LEARN ABOUT SCALE MODELING by Kenny Kear

Title: SO YOU WANT TO LEARN ABOUT SCALE MODELING.

Greetings to all scale enthusiasts. First, allow me to introduce myself. My name is Kenny Kear, I’m a member of the USSMA (Member #152). I’m also a life member of the Academy of Model Aeronautics (L92357). I have been married for 30 plus years to my wife Mary Lee Kear (USSMA member #153). I’m a USAF veteran. My wife and I have 4 kids (all grown) and two grand kids. I have been involved in model aviation since the age of 8. I’m currently employed at Honeywell International as a lab technician testing land, sea and air components for various customers around the world.

I would first like to get this out in the open before I start. I’m a regular modeler like the rest of you out there. Just having a great time doing the things I love to do… Modeling. I haven’t published any books or any of that jazz. Just creating models and having fun doing it.

(First things first… it’s my father’s fault I’m doing this scale stuff. Thanks dad. “Rest in peace”.)

Being my mother didn’t have a lot of extra money to support my hobby I had to find a way to fund my passion. I started collecting soda pop bottles using my oldest sister’s faded blue bicycle. The frame had the big cutout in the middle for girls and big baskets in the rear on both sides. I couldn’t sit on the seat and reach the pedals so I rode the bike standing up on the pedals to all of my destinations. You know …back alleys, garbage dumpsters, gutters, etc., where I found my greenbacks in glass form. I took my pop bottles down to the nearest convenience store and cashed them in for the big pay-out. (Yep...about $3.00… I had struck it rich). I then went to the local hobby shop where I purchased a stick and tissue rubber powered sport model with the help of dad (I was only about 9 years of age at the time). I built so many rubber models that I just knew that I had kept the hobby shops and main manufacturers in business for some time while also keeping the neighborhood clean.

At the age of 12 I started building more scale models like Guillows, Comet etc. I started adding more and more scale details to them. Please keep in mind that these models still had to be built light and strong along with adding all the other neat scale details on them.

After a few years of building and flying (AMA Gas Free Flights along with scale rubber models) I felt pretty confident of my building and flying skills. I decided to take the next step.

Nope, not control line, they made me dizzy and I would let go of the handle and turned them into a free flight for a few seconds until they demolished themselves. Well, you guessed it…I got the itch to build and fly R/C models. “Oh boy the fun has started now”.

I would build trainers and semi-scale models that were proven to fly from manufactured kits like Sig, Sterling Models etc. I would then add small details to them trying to keep the weight and cost down on each model. I used a lot of rubber power model building techniques to do this. Well, as I was taught by dad you have to learn how to first crawl before you walk and then run. And so my scale adventure had begun.

OK, for the beginners, let’s look at some basics. I would have to imagine that you already have a current AMA license or (equivalent) and have earned your pilots wings. Those are biggies…

With having the basic fundamentals of R/C flying under your belt and a dozen trainers or more flown/crashed/repaired you now feel that the trainers are getting to be a bit boring. So, the thought strikes you that you would like to build that scale masterpiece and show the world and (your favorite buddies) that you have the talent to build a scale model and fly with the “Big Dogs”.

Now for a little meat and potatoes to get your taste buds working…

So, as a beginner in scale modeling let’s take a look at how you can accomplish some of these tasks. Put on your thinking cap use your imagination and let’s begin. In today’s world there are still some kits available along with a ton of ARF’s (Almost Ready to Fly) & ARC’s (Almost Ready to Cover) to pick from. Pick the kit/ARF/ARC that meets your available budget, time and building skill level.

Most modelers on the average will pick an ARF or ARC. These models have the least amount of work to get them in the air for that ultimate pleasure…looking and flying scale.

Let’s pick an ARC model to start with. You will receive a pre-built model almost ready to cover, install radio/engine/landing gear and then detail to your likings.

First inspect the model for any defects that might have happened in the manufacturing process. Repair as necessary. When satisfied, start with small details like aileron/elevator hinge gaps, wing saddle fit, cowl alignment, engine installation etc. Make sure everything is correct per manufacturer’s instructions and that you are happy with everything.

Next, look on the Internet for that ultimate color scheme or go through your favorite documentation packages and choose the one you want to model your ARC after. Sometimes I choose a plastic model that catches my eye and use it for the project. (Editor’s note – plastics are a good source of color detail and sometimes 3-views.)

Look at the details presented to you and choose a couple of them to put on your model. Be reminded that the model you are doing is not a true scale model. It is more than likely a stand-off scale model. You are using this model as a test bed for the scale master model(s) to come.

There are multiple areas on your ARC model to tackle. Let’s list a few of them:

  1. Panel lines

  2. Fabric stitching/pinking

  3. Rivets/screws

  4. Fiberglassing

  5. Elevator/Aileron/Rudder/flap Hinging details

  6. Cockpit detailing

  7. Dummy engine etc.

We can talk more about these details later.

Please don’t think you are going to do them all on this model. Some details will be easier than others. Pick one or two details to apply to the model.

If you ever thought you wanted to be the master of illusions, now’s your chance. On my scale masters project I first look at taking the full scale subject and put it in a shrink machine. This is what I want my model to look like when it is finished.

I also do one other thing before I start my scale project. From start to finish “I build the model in my mind to the point of completion”. I’ll study the plans and the full scale first and go through all the techniques that I’ll be using before I glue one stick together. It’s a lot cheaper this way.

Let’s pick an area on your ARC to start with. Let’s talk about “Covering”. With an ARC model you need to look at the complete airframe and see if all the imperfections have been removed. Nicks, dings, dents will show up like a bad paint job on a car. If the foundation is poor, you will only magnify it when you put your covering over it. Take the time to putty /fill and sand out any bad spots.

If you have a few small dents that you want to remove without filling you can soak the balsa with a few drops of water and steam them out with your Monokote iron (without the sock) until the water has completely evaporated and the ding/dent has come flush with the surface. If needed, lightly putty/fill and sand out those spots that didn’t come out with the steaming or didn’t meet your specifications. I use “Patch and Paint” for those dings/dents. It can be purchased at your local hardware store like “Home Depot” etc.

Pick the covering you wish to complete your model with. I’m an old “Dope and Fabric” guy but have used Monokote for years. The choice is yours depending on what you are trying to achieve scale wise.

Mr. Bob Frey (of Phoenix AZ) has experimented with Monokote in the sense that sometimes fiber glassing, priming and painting can get a bit heavy and costly and time consuming. With great success he has taken many models and Re- Monokoted them and added scale panel lines, texture and even repainted over the Monokote to achieve the proper paint scheme and details desired.

For me there is a particular way to apply Monokote so that you get a real good finish when done. Always keep in mind the foundation of the airframe. It needs to be sanded with fine sand paper. This will give the model that foundation you need for a fantastic finish whether you use Monokote or dope and fabric. Start with 320 grit and progress to 400 grit to give it a real nice finish. I have even used 800 grit for the final sanding on some models. The finished sanding will give the covering that drop dead gorgeous finish you are looking for. ALWAYS sand in the direction of the balsa grain. Don’t get too excited with the sanding or you can make the balsa too thin and you know what happens then...

If you can feel a glue joint on cap stripping or sheeting joints etc. the Monokote will magnify it when applied. This is very common with CA glues. The heat from your iron will cause the glue joint to grow/rise. (Bear in mind that the glue is harder than the balsa – sand joints with care. Editor). Try to get the joints as smooth as possible.

After you have sanded your masterpiece to perfection you need to apply compressed air carefully (approximately 20 -30 psig.) to the entire model to remove all that pesky balsa dust. Take your time with the compressed air. Monokote needs to stick to the balsa. A layer of balsa dust between the wood and covering will do nothing but give you a major headache and a model that looks like…well you fill in the blank(s).

Now for the covering process. Stick with me on this, the outcome will be astonishing. With your model sanded and prepped for covering set you covering iron to manufacturer’s heat specifications for the particular covering you are going to use. We are going to use Monokote at this time.

Pick a small part like the stabilizer to start with. Start with the bottom surface first. Cut the covering about 1.5”- 2.0” oversized for the surface to be covered. Remember to remove the clear plastic backing on the Monokote. Don’t laugh…I have heard many tear jerking stories about how that stupid Monokote didn’t stick like it was supposed to. Stupid Monokote

Lay the covering down on the bottom side of the stab with the side that you just had the clear plastic backing removed. Lightly flatten it out so that you have that 1.5”- 2.0” oversized covering as equal as possible all the way around. Pick a tip and tack the covering down with about a quarter to half inch tack. (Do not tack on the very edge. You’ll see why later.) Go to the other tip and lightly pull (or pre-stress) the covering so that the covering shows little pull/crease in the covering. Tack this tip down like the first tip. Allow to cool.

Go to the center of the stabilizer. With both hands, pull the center of the covering equally LE and TE out at the same time so that the pre-stress crease from tip to tip goes away. Release one hand slowly not allowing the other hand to move and tack that area down like before. Allow to cool. Then lightly pull the other center piece of covering outwards so the wrinkles go away. Tack this edge down like the others. Now go to a corner of a tip (just pick one) and lightly pull like you did on the other tacking’s and tack it down. Repeat same procedure to the other three corners.

Now, look from the center of the stab to the tip and go half way out and pull the covering like you just did with your two hands earlier. Tack down LE and then TE. Repeat same procedure on the other side of the stab.

After the tacking has been completed, pick a starting point on the stab and lightly pull outwards on the 1.5”- 2.0” oversized covering at each location that you are going to apply heat/iron on. Keep sealing the covering all the way around the stabilizer with this technique. Apply a small radius of the covering on the LE/TIP/TE etc. while lightly pulling and ironing the covering down. (This is to keep the covering from loosing up when you apply heat from the heat gun).

When you get about a quarter of an inch from the start/finish area “STOP” and leave that quarter of an inch open for the hot air to escape from the heat gun process. Take your heat gun at this time and turn it on. Allow it to come to temperature. Now, apply the heat from the gun over the covering in a circular motion starting from the tip area getting closer to the covering to remove any wrinkles. (DON’T get to close or you will melt the covering). Keep the heat gun moving across the stab just enough to remove the wrinkles. When you get to that open area of the covering stay away from it at this time.

Now we are going to pull the extra covering around the LE/Tips/TE for a smooth finish and” no wrinkles”.

I do this by putting the stabilizer between my legs to lightly hold it. CAUTION - make sure you are wearing long pants like Levies’ etc. (It gets a bit warm when doing the technique). I like to start at the tip area. This area is the most difficult area to make look good and make smooth without any wrinkles.

With the heat gun blazing away and the part between my legs I start pulling on the extra covering (a little harder than previously mentioned when tacking) outwards and at the same time I move the heat gun in closer to the covering and in a circular motion apply the hot air to the area I want to stretch around the surface. Watch those fingers - they can get heated up when doing this.

This action will happen quicker than you expect. The covering gets hot and starts the stretching/melting process. At this time you pull the covering around those pesky compound corners as much as it will yield without melting or ripping off. If a wrinkle appears go back and repeat the process until you are satisfied.

Repeat this same process around the entire stabilizer. When you are satisfied take a NEW #11 X-Acto blade and trim the excess covering in as straight line as possible so that you leave at least 50 - 75% of the LE/Tip covered around the edge(s). Take you Monokote iron that has been set to the proper ironing temperature and seal the edges down completely. This will be enough covering so that when you do the other side of the stabilizer it will be enough for the other covering to adhere too and create a good seal.

Now, you’re asking what happened to that quarter inch air hole for hot air to escape. You’ve sealed it up but it’s OK. When you gunned the wrinkles out earlier it did the job it was put there to do. Now do the other side of the stabilizer the same way. When finished and you want to seal the covering to the wood you can gun it down or use you Monokote iron (with a sock installed).

If you use the heat gun you’ll need a hot mitt. You can purchase one from your local hobby shop or go to your favorite discount bargain store and pick up one there. I use the terry cloth type hot mitt that my wife donated. They seem to be a bit more flexible or softer after they are washed and dried. Bottom line is to make sure your mitt is not coarse or abrasive. It will transfer its signature to you covering and down to the fine sanded balsa wood finish you worked so hard to perfect earlier.

When you are ready to seal the covering to the top and bottom of your stabilizer you will need to take that sharp #11 X-Acto blade and make a small slice on an outward angle (like a 45 deg. or more) towards the corner of the tip area. This is to allow the extra air to escape while pressing the covering down after being heated again. DON’T make a vertical cut in the covering or the heat will split the covering and make a hole there. NOT GOOD.

First place the stabilizer on a flat but soft surface so that you can work with it and not damage the other side. It also needs to be as stationary as possible. Start close to the tip of the stabilizer and work your way across to the other side with the heat gun. This is to re-tauten the covering getting a little closer as you go so that you start to see the covering tauten. Again move the heat gun in a circular motion. Do not stay in one place to long or you’ll burn a hole in the covering. Move the heat gun closer as needed to get the covering to tighten and not take all day. This is about a 1 second interval moving the gun approximately 1 inch in movement and about 1 - 1.5 inches from the covering. (This is a “BIGGIE” when working over open bay areas like wing bays etc. The solid surface is a bit more lenient but it can still burn through the covering). Watch that cut in the covering. Stay away from it until the end of the process.

Go back to your starting point and start the process over again except this time you are going to follow with your hot mitt and seal the now well-heated covering into place. Remember the covering is being heated and tightened at the same time you are pushing the air out and pressing the covering down into place with hand pressure from your hot mitt. Keep everything moving until you get to the other end. Repeat the same process again but move the operation down an inch or two. Be aware of the slice you put in earlier. Don’t penetrate too much heat into that area. When the slice is rubbed over it will seal itself. Again go over the slice fairly fast.

If you want, use the Monokote Iron to do the same procedures as stated above only use the iron in place of the hot mitt. If you wish to install the Monokote iron sock please do so. You will have to increase the temperature of the iron to compensate for the sock.

The proper procedure for putting on this type of covering is this. The fuselage should be done starting on the bottom then the sides and then the top. This is to seal the model and keep fuel/oil from getting under the covering and loosening it etc.

The next procedure will be used on the aileron and the aileron/wing sockets. (Very special note: MAKE SURE YOUR TONGUE IS IN THE PROPER POSITION OF YOUR MOUTH BEFORE YOU START. Mine is in the right corner.) The vertical stab and rudder are done the same way as stated below.

Start with the ailerons and cover the ends first with small scrap pieces. This is called “Facing”. These pieces are fairly large. This is needed so you can hold them with your fingers when pulling the covering.

First center the covering on the aileron end and use the iron to tack it. Start at the leading edge area of the aileron. Tack it down and then go to the trailing edge and lightly pull the covering so that it creates that small crease (like that mentioned in above procedure) and tack it down. Pick a side about half way and pull one edge out lightly in the center area so that the crease starts to go away and tack it down. Repeat for the other edge. Keep sealing the covering while lightly pulling the covering outwards until it is completely sealed down on all edges.

You will need to leave a small opening (like the stab) so that the air can escape. Once happy with everything seal the opening. Don’t place too much heat on the end surface or you will get bubbles under the covering.

Depending on the size of the aileron end I use the heat gun to relax the extra covering (while pulling at and around the corner). This happens quickly as noted in the stabilizer covering procedures above. You can use your iron if you wish but the heat gun gives you better finish. “DON’T APPLY HEAT GUN AIR ON THE SEALED “END” OF THE AILERON” it will loosen (and make you very mad). Only apply heat gun air on the loose covering and the edge of the aileron.

The purpose for this is to get the covering to flow around those pesky corners again. After you are satisfied with the aileron end, take the iron tip and seal the covering around the aileron ends /top/bottom. This should leave you with approximately 1/8 inch of covering that is attached to the top, bottom, front and rear of the aileron end. Take a straight edge and use a #11 X-Acto blade and cut/leave a 1/16 inch perimeter of covering around the aileron end. Cut only through the covering. Try not to cut into the balsa. (This is a TONGUE THING.) (See note above).

Use this same facing technique for the trailing edge of the wing/aileron socket where the aileron leading edge is to mate up with the wing. After all of the “facing” has been applied then you can start the real joy of covering your ailerons and wing etc.

The aileron can now be covered in one piece starting from the “bottom” of the trailing edge all the way around to the “top” trailing edge. “No” seams to lift up.

Us the same covering techniques as mentioned above in the stabilizer covering procedure. The wing can be done in 4 pieces or in two. I recommend that as beginners you go with the 4 pieces. Again apply the covering as you would the stabilizer. Bottom first and then top. Give the center section (top & Bottom) at least a ¼ inch overlap.

I think by now you get the idea of how to apply the covering to get a real good finish. If you get the “PERFECT” covering job the first time, I tip my hat to you. It took me many of models practicing the techniques before I came up with the covering job I was very proud of.

If you have any questions …Please ask. I’ll do my best to clarify them for you.

Kenny Kear









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