Building Tips and Techniques

Gluing Foam Panels Edge to Edge (a.k.a. "The Hinge Method")

As the first steps in building the Cozy airplane, the builder is instructed to make the seatback and bulkheads by applying 5-minute glue to the foam panels and gluing them edge to edge.  While sounding simple enough, the uninitiated builder soon ends up with glue everywhere but where itís supposed to be, not to mention ill-fitted parts.  So here's my "Hinge Method" for achieving perfect glue joins without all the muss and fuss.

Here's everything you need to do a perfect job -- the panels to be joined, duct tape or box tape (I prefer duct tape), 5-minute epoxy, cup and mixing stick, sandwich bags, and gloves.  Some of you may recognize the B33 and R33 strake rib in this picture.

Step 1 -- Vacuum the panels thoroughly, butt the edges together, and align the pieces as necessary.  Apply one length of duct tape over the seam to form the hinge.  The hinge holds the pieces together and keeps the glue from running underneath the parts.  Leave a small overhang on the tape to aid in removing it.

Step 2 --   Carefully turn the panels over.  Apply one length of tape on each side of the seam, leaving overhangs as in the previous step.  The purpose of these tapes is to catch any glue run-off and keep it off the foam.  

Step 3 -- Lift at the seam and stand the panels up into an upside-down V with the now-opened "hinge" facing upward. (For larger panels of foam, it's easier to hang one panel from the edge of a table.) By standing the panels on edge, the panels are still joined together at the hinge, but the seam now forms a channel into which to pour the glue without fear of it running down the panels.  

Step 4 -- Mix up some glue and quickly pour it into the corner of a sandwich bag.  Cut off a small hole in the corner, and use the bag like a cake icing tool to gently dispense the glue into the seam.  You don't need a heavy amount of glue, just a contiguous bead. 

Step 5 -- Collapse the V by pulling on one side of the panels.  When the panels fall flat onto the table, the excess glue will squeeze from the hinge. Quickly wipe away the excess.

Step 6 -- With no delay, hold the panels completely still and remove the tapes from each side of the seam.  When the glue is set, flip the panels over and remove the hinge tape.


Voila! The panels are glued together perfectly without gaps in the seam and without excess glue all over the foam pieces. Very clean. No clean-up and no more sanding glue ridges prior to glassing.