CL Aerobatics
Curt Contrata
Tips for applying perfect painted-on trim
FOR ME, ADDING color trim to a model is the most enjoyable part of the building process. That is when the model takes on all of its personality. My father used to comment on how I would begin to paint the model in my head before I would even cut the first piece of wood. He was absolutely right, and to this day I plan the finish before I start construction.
Having the right tools for applying the trim colors is important. Perhaps the most important item of the entire process is the tape you use. The top choice among most top modelers is the blue Scotch Plastic Tape (471). It is low tack, can be removed and repositioned many times, and can be left on the model for several days without causing problems.
This tape is also smooth sided, which makes for an extremely clean edge to paint against. It is so much better for our application that I no longer need to prespray edges with clear or the base color to avoid trim colors from bleeding under the tape—something that was mandatory when using paper tapes.
Scotch Plastic Tape also comes in various widths, which is a huge advantage. I generally purchase several widths, each with a specific purpose. The 1/8-inch-wide variety is ideal for all curves, and the 1/4-inch-wide tape works for almost everything else. I generally pick up one roll of the 1/2-inch-wide kind, just in case.
Having different widths of tape is useful for quickly measuring widths of stripes and the offset between them. Sometimes it helps to lay down a temporary piece of tape to keep everything parallel. Although tape is available in a variety of widths, the three I mentioned complement each other and should be all you need.
The tape’s flexibility is a blessing, but it can also be problematic if you are not careful. It takes a bit of practice to make a straight line, and it is easy to put a curve in the end of a line with your fingers as you set it in place. As with everything, there are some tricks you can use.
Always cut a piece several inches longer than you need. Holding an end of the tape in each hand, lay it down a few inches before where the trim needs to begin to get a running start at being straight. Sight down the tape as you bring the other end toward the model, being careful not to stretch it.
Chances are that you will miss the second point or put a curve in the tape. If this happens, just pull up one end and try again.
Also included in this column is information about:
- The new PA Merlin-series .85 engine
If you keep having difficulty with a slight curve at the end of the tape as you apply it, put the second end on a #11 X-Acto blade that is turned around in its handle. Holding the handle in one hand, sight down it and tape as you apply it. This technique works well for keeping long pieces of tape straight.
The 1/2-inch-wide tape tends to stay straighter on its own; however, it is more difficult to navigate around other colors and may require more trimming. The 1/8-inch-wide tape work great for going around corners and canopies but can be a challenge to keep straight.
It is difficult to apply the paper masking where the 1/8-inch-wide tape has been used since there is little surface area with which to work. When I use the 1/8-inch-wide tape I generally overlap a few pieces to make a surface that is at least 1/4-inch wide, providing more surface area to which to stick the paper masking.
Regarding the paper masking for large areas, it is well worth the investment to purchase a portable masker from a supply store for automotive paint and body repairs. I have tried a variety of methods to mask off large areas of the model to avoid overspray, and the best way to do it by far is the way the pros do it.
CL Aerobatics
Curt Contrata
Maskers hold a roll of nonabsorbent paper and a roll of paper masking tape. As you pull the paper off the roll, the tape is automatically applied to one edge of the paper. After you use a masker for the first time, you will wonder how you ever lived without one. If your time is at all valuable, this device will pay for itself on your first model.
For a full-size Aerobatics model, I typically use two rolls of 8-inch-wide masking paper and four rolls of paper tape: one each of 1/8- and 1/2-inch and two rolls of 1/4-inch-wide blue Scotch Plastic Tape.
Another important trimming tool is an airbrush. I cannot imagine how anyone can finish a model without one. There is nothing like using an airbrush to apply trim colors and retouch all the little mishaps that happen along the way. It is the perfect miniature spray gun and is great for blending colors.
Everyone with an airbrush should have as many small jars as there are colors on the model, one for clear, one for thinner, and a couple spares. I use my airbrush for all the stripes and small trim areas on the airplane, and as a result I tend to change colors frequently. I also tend to break the glass jars once in awhile, so I try to keep extras around.
By putting out little material, it is easy to control how much paint actually goes on the model and, for that matter, how much builds up on the edges of the tape. If you apply too much paint when shooting trim colors, it will take more clear coats to make the edges smooth to the touch.
After the trim has been sprayed, you need to remove the tape and clean the edges. To remove all the masking, wait until the color has completely dried and then take your time. When removing the tape, pull it slowly and as flatly as possible. If you pull it toward the trim color you just sprayed, sometimes it will leave a cleaner line.
No matter how careful you are when spraying and then removing the tape, there will be paint flashings along the edges of trim color that need to be cleaned off. People swear by different methods, but no single technique works for me on the entire model.
For years I was told to use the edge of a credit card, and then someone suggested using a Scotch-Brite pad, which is like a cross between plastic steel wool and sandpaper. I have also had success with rubbing a piece of fresh paper masking tape down on the paint edge and then pulling it off.
You will probably find that using a combination of methods works the best for removing the paint flashings and cleaning the edges of your trim. It is crucial to keep the work area on the model—and your tools—as clean as possible. It is easy to rub the little pieces of trim color into the base color and quickly make a mess.
When it looks like all the flashings are gone, I go over all the edges with fine 1,500-grit sandpaper. This takes a light touch to do correctly and should be done slowly with clean, dry paper. If done correctly, this takes down any sharp edges that remain and will make the rest of the finishing process much easier, especially if you plan to ink the edges of your color.
A great advancement in technology that we can benefit from for masking is the vinyl sign shops that seem to be showing up everywhere. For our application, it is possible for them to provide a low-tack vinyl that can be applied as a spray mask. These masks are extremely easy to apply and remove, and they can be used for larger text and graphics.
The company I am using for my current project is RG Graphix, and the staff has been more than helpful. The Web address is www.rg-graphix.com or you can reach the company at (724) 981-2914. For fine text, they can print on thin clear vinyl, which is then contour-cut around the letters, making something that resembles a decal.
In the last column I announced that Randy Smith of Aero Products had introduced a new engine: the Merlin-series PA (Precision Aero) .75. It complements the Merlin Ultra Lite PA .40 that was released last year. Since that news, several of the .75s have hit the air and are receiving great reviews as being the smoothest and strongest Aerobatics engine ever produced.
Randy has since announced that he is developing a Merlin-series PA .85 from the same case. This is truly an exciting time to be involved in this event. MA
Transcribed from original scans by AI. Minor OCR errors may remain.
