Disclaimer: The window rock-guards worked well for short distances or being stationary. We did experience high winds in West Texas and in New Mexico and the rock guards did not perform as well as we hoped. The polycarbonate cracked under high stress.
Like most people, we went back and forth on what is the best (and most cost-effective) way to protect our panoramic windows. While we could have ordered custom rock guards direct from Airstream, it just simply wasn’t in the budget.
We have seen other ways people have protected their windows ranging from duct tape and a box, which we did initially to get our Airstream home…
To creating canvas wraps that snap on…. to cutting Lexan (a clear Polycarbonite sheet similar in appearance to Plexiglass) cut to fit and fastening with Velcro to the windows so it can be easily removed and reapplied. All fine ideas, however, we wanted something more permanently mounted in case we ever stay at a golf resort or have a run-in with a reckless landscaper unaware of spitting rocks up with the mower. But still able to remove should the panels ever get damaged or cracked.
We started out with a template of the window using large paper and a crayon to give us the exact shape of the window
Then cut the template out of a cardboard box 2 inches larger (all around) than the end of the window to ensure complete coverage.
We used and cut a .093 Palsun polycarbonate sheet with a jigsaw using a fine-toothed blade. You can order Palsun polycarbonate sheets with UV protection, which will prevent it from yellowing over time. While I believe you can order the pieces from your local big-box hardware stores, we chose to order ours from a local plastics fabrication shop.
Once we had our pieces cut, we began drilling the holes in the end cap just along the outside of the upper frame and inside the bottom trim / stripping.
To keep the rock-guards off the windows and held securely in place, we created spacers from conduit clamps (6 per panel – the top 3 painted to match the end cap color) with a hole drilled through the center to fit a bolt and fastened with (long) 5/32 rivets to the airstream skin. (We made sure to fill the holes and caulk the rivets with Trem-Pro 360 and used rubber washers to keep the seams leak-proof)
Starting with the upper and lower inside seam of the panel, we drilled holes, one by one, into the Palsun polycarbonate sheet; sliding the bolt through and mounting it loosely each time ensuring it wrapped around the window as we wanted it. Then used a marker to indicate where the next hole would go.
The full panel was then secured with stainless steel machine screws, washers and locking nuts to hold it firmly in place without scratching the rock-guard as it bounces and wiggles down the road.