Arntrol Extrol Expansion Tank Leak

My expansion tank is leaking, there is about a 1/8" hole in the side about 6" up from the inlet side, can I just repair this hole or is there damage internally where I would need a new one? I went to the website to see how they work and it doesn't look like it would hurt if I just fixed the hole. Any thoughts? Thanks

This is just a guess...if it is rusting out, you are only seeing the tip of the iceburg...get ready for a new one and sooner may be better than later.