If wing tank bladders have sat, installed for 10 years, while structural and other repairs were being made, is there any treatment that rejuvenates them? I suppose they are Goodyear, I m not sure. The have been inside a hangar for this time. I know that certain old leather like couches and jackets can be wiped with a preservative and really be brought back to good condition. Prior to siting empty they were most always full of fuel. Thanks