Yellowed Silicone?

[docturtle91b]

A friend of mine just gave me two tanks that were in his crawl space for about 5 years. The silicone on one is yellowish. I'm curious, is this normal for old silicone or should I be worried about some kind of contamination? I'm going to replace it anyway just not sure if its a normal sign of age.

 

[Motoxer777]

id say its just old. i would reseal the tank. dont want to chance it if any of it is dry and cracked

 

[skjl47]

Hello; Silicone has absorbed color from dye medication before in my tanks. Methylene blue for example. It turned the silicone a light blue but did not affect it as a seal.