Originally Posted by Jim Foster
Plexiglass reacts to Acetone. I removed the curved stone guards on our Excella, put them inside up on a table and applied acetone to the cracks using a syringe with a very fine needle along the cracks. There was also inside damage due to hits on the outside of the guards. Applying acetone seems to have stopped the spreading of that damage.
If you know someone who is diabetic, the disposable syringes they use are perfect for applying acetone for many plastic repairs. The syringes are also plastic, however they do not react to the acetone.
Care must be taken not to smear the wet acetone away from the cracks. If you do damage the inside of the guard in this manner, it may be polished out with tooth paste after all is dry and hard.
This trick was passed on to me by a tech at Vintage Air, a company that makes aftermarket A/C systems for Street Rods and other cars. Their plastic Heat and A/C cases are bonded together using acetone.
Thanks for your suggestion for arresting the crazing that has already occured. I will be doing this as soon as we get home next month. Hopefully, information about what was causing the cracking on my stone guards will help other Airstream owners avoid this problem. The expense of replacing stone guards is a major outlay that could be avoided if proper cleaning procedures were understood.