Almost every helicopter uses rubber grommets to soft mount the canopy to the helicopter structure. Installing these rubber grommets to the canopy seems like a very straightforward task, but some techniques just work better than others. Over the years this is the technique that I have developed, and I hope it’s of help to you.
Before I drill a hole in the canopy I first stick pins through the canopy where the grommets are to be mounted to ensure they line up with the correct mounting locations on the helicopter itself. The pins are moved as required to get the alignment just right, and then the proper size holes are drilled.
I then take a little petroleum jelly and work it all over the rubber grommet, which has the following benefits. First it lubricates the rubber making it easier to install on the canopy. Flexing the rubber grommet also makes it more pliable and easier to work with. Lastly, the petroleum jelly moistens the rubber to keep it from drying out with age.
I then use a blunt object, such as a hex driver to force the rubber grommet into the mounting hole. When the grommet is halfway through the hole I finish the job my pulling on the edges of the grommet from inside the canopy. This ensures proper canopy alignment with rubber grommets that will last for years without drying out.