Model Repair, 10-Steps to a Fast Fix

Jul 06, 2011 2 Comments by

We’ve all done it. That one dumb thumb move, the very brief moment when
our brain wanted to go right and our thumb decided to go left. There’s nothing
you can do but pick up the pieces and take them back to the shop. Some
professional aircraft impact testers even have a trash bag in their flight box
for damage retrieval. The first rule of crash repair is to pick up all the
pieces, but once you have all the parts home, what’s next? Let’s look at one of
the more common impacts, wing damage. This type of damage can happen anywhere
and is perhaps one of the more common repairs. Let’s see how we can repair this
wing and get back into the air by the next weekend.
YOU’LL NEED
Here are some of the tools and repair supplies you may need for your repair.
You won’t use all of these every day, but you’ll need many of them every time.
Supplies include CA glue, accelerator, epoxy, heat-shrink film, scissors, mixing
sticks, tape, iron, trim iron, #11 hobby blade, pliers, reinforcement material
(fiberglass) and extra balsa.
1 DAMAGE

Here is the damage to the wing that needs to be repaired. Fortunately, most
all of the parts are still inside the wing because the covering held
together.
2 INSPECTION

Cut around the damaged area and leave the covering attached to any rib that
can still support it. Inspect the damage inside and remove the broken parts to
use as templates. Here the center rib is damaged beyond repair, but the adjacent
ribs can be used as a base part to which I can glue the new ribs.
3 MAKING THE TEMPLATE

By piecing the part together, I was able to make enough of a rib to make my
first template. After checking the fit, I needed to make another template until
I got one that was just about the right size. The right size is one that is just
a tiny bit large, so it can be reduced in the next step.
4 FINISHING THE TEMPLATE

After getting a piece that is slightly larger, I sanded to fit. I am looking
to make this part so that it fits snugly in place between the spar and the
leading edge. Once I have the perfect fit, I’m ready to make my repair pieces. I
will label this template with the name of the plane, just in case I need to use
it again.
5 CUTTING THE PARTS

Now I can use this template to cut out my three ribs. Use a sharp hobby blade
and keep the knife vertical to make a straight edge with a clean cut on the
ribs.
6 SANDING

Don’t put away that sanding block just yet. Use it to fine-tune the part for
an exact fit. I like to sand all the parts together; this way I can make sure I
have the same size ribs going across the wing.
7 PARTS INSTALLED

All three ribs are now glued in place and ready for covering. I used CA glue
to place them so I don’t have to wait to move on to the next step. The stubs for
the broken ribs are used as a glue surface to give the new ribs more “bite.” If
you use epoxy or resin glue, just give it time to dry before adding the
covering.
8 CUTTING THE COVERING

Cut the covering to extend beyond the undamaged rib; now you can tack it all
around the damaged area. Finding covering that matches the base can sometimes be
impossible and you have two choices. You can either use the covering that is
close and live with the slight deference in color cast or choose another color
with a design in it and duplicate it on the other side of the plane. I am fine
with my repair piece being a slightly different hue.
9 APPLYING THE COVERING

Tack down the covering to all the solid wood around the damaged area and then
use the heat gun to shrink it down. If you can’t find the same brand of covering
that was used on the aircraft, make sure that your patch piece is of a material
that uses a lower heat setting. This way, you will not melt the original
covering.
10 FINISHED REPAIR

Here’s my finished, repaired wing all ready for its next flight. Total time
for the repair: just a little over an hour. That’s less time then it would take
for me to assemble another plane and a heck of a lot less money pulled from my
wallet.
You can apply these steps to any damaged area and save that crashed aircraft.
Remember: the money you save by repairing that crash can be used to get that
great high-end radio you’ve been drooling over. That’s worth an hour of your
time, isn’t it? Enjoy!
Featured News, John Reid

About the author

West Coast senior editor About me: I’ve been involved with RC aircraft since high school and have flown just about everything. I started my RC career with scratch-building, but now like many pilots I rely on ARFs to get me in the air. My main focus is on pylon racing, aerobats, combat and scale warbirds.

2 Responses to “Model Repair, 10-Steps to a Fast Fix”

  1. High Nitro says:

    Nice article John. Where did you get that picture of my trash can? —Tony I.

  2. John Reid says:

    I know it’s not my trash can, mine is much bigger, but I do have the same content filling it up.

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