OUCH is right.
I did that with with an old ham antenna many years ago. I found a very simple and inexpensive fix to this.
I bought a 14oz. can of KRYLON, 'Crystal Clear' acrylic spray coating, # 1303, at a craft store for $4.29. This stuff dries very fast and protects against the elements extremely well. I used this to coat[3 coats] an aluminum, ham antenna [MOSLEY, TA-33], that I placed on my tower in 1979. When I took this down and gave it away last spring, to my surprise it looked like new; especially since I am only 6 mile from the coast. It is now back in service on another tower without any needed maintenance/parts.
I have used this spray on all my marine antennas, the oldest was from my 1988 [SeaRay] boat. This antenna is still as fresh as when I first coated it.
The KRYLON is designed as a permanent protective coating for finished water colors, charcoal, pencil and color ink renderings. It appears to be moisture proof. I have used it on maps, also. It is somewhat flexible, though I would not expect it to keep its properties if the material/paper were folded. A little goes a LONG way.
This is one of those items that would fall into a <$20, in this case <$10, idea to keep around that shop.
I hope this helps extend the life of an otherwise working antenna.