how often and when is the chapel open i pass by it often but i rarely see it open to the public other than when they have the feast.

I pass it all the time many times throughout the year and it is never open I think it might be private and exclusive to being a member of the society to have a cess or to even visit because this isn't the only one that's not open when the feasts are not being held all them are always closed.

I am not sure, perhaps leave a note, or pop into St. Joseph Society on Hanover and see if they have some contact details.