chewing fn badly

[Cookie]

So my two chins have a fn 142 and they also get out, have dustbaths etc regularly but they still chew the bars on the cage! It was just annoying to hear at first but now I've been looking closer and in the corner by the ledge where they sleep the coating is actually coming off and theres actually some sharpish bits I had to smooth down. Is there anything I can put on the bars to stop them from doing this? If they keep doing this I'm worried they might get a cut in their mouth or something from the jagged edges that are left behind, not to mention its wrecking their cage that hasn't even been used for half a year yet. It's only in the one spot and about 5-6 bars.
Oh and before you ask, yes they do have lots of chew toys(wood), both hanging and toss toys as well as lots of pine ledges and fleece items (hammocks, tubes, liners etc) for entertainment.
Thanks!

 

[ChinnyMom]

try attaching a spare pine shelf to the area of the bars where they are chewing. put it flat side against the bars, so that it is flush with the side of the cage.

 

[Chin_Parent]

Chalupa chewed her cage a lot, and I just weaved a bunch of palm leaf shredders through the bars, and now she doesn't do it. That'd probably be helpful to stop them from doing it. Surprisingly too, she hasn't chewed the bars anywhere else.

 

[Godofgods]

my male does that anytime he get worked up about not being able to see his girl anymore. Generaly in the same certin areas to. So far i havnt had any luck in getting him to stop