EPP Foam Plane Repair with Window Screen

After successfully building my new Twisted Hobbies Edge 540, I took it out to the flight field last night for its maiden flight.  I thought that I had carefully set the throws on all the control surfaces correctly pre-flight.  Even old timers like me make a bonehead move every once in a while and this was mine.  I failed to notice that the ailerons were completely reversed.  So, up the new plane went, followed by a quick down.  My maiden flight lasted all of two seconds and the EPP fuselage surrounding the motor firewall was broken.  Arrrrgh.

 As we all know, EPP mends pretty well.  However, I have noticed that a number of other guy’s planes motors had pulled out of the EPP foam at the fuselage and even more guys have had the tailskid rip out of the tail even on simple landings.

 So, off to the workbench for a “screen door” fix.

 What you will need:

• A small piece of fiberglass window screen – this can be purchased very inexpensively from your local hardware store or you might even find a piece of it in your garage.  Be sure to use fiberglass and not the aluminum kind
• Scotch Super 77 Multi-Purpose Adhesive
• Loctite Go2 Glue
• A razor knife

• Waxed Paper
• Tongue depressor or coffee stirrer

The Fix

1. Cut a piece of the screen to cover the area that you want to reinforce or repair.  The screen is easy to cut with a pair of scissors or your razor knife.
2. Put the screen face up with the side that will be attached to the screen on the waxed paper.  Apply a light coat of the Scotch Super 77 to the screen.
3. Apply the screen to the place that you wish to reinforce on the plane.  The screen will easily wrap around 90 degree angles. 
4. After the screen is tacked to the planes surface, apply a bead of the Go2 Glue over the surface of the screen with the tongue depressor.  The Go2 Glue is clear and very flexible.  You could also use medium to thick foam safe CA.  If you have ever worked with fiberglass, this is a very similar process to applying the resin through the fiberglass.

This technique can be used to make high stress areas tough, or even make foam hinges less susceptible to cracking and tearing.

It’s a very lightweight repair but is extremely robust and does not detract from the plane’s line and color much.