My husband and I have been restoring a family home built in 1918. It had been sold out of the family and we have recently bought it back. There is a chimney in the middle sitting room that was painted with glossy black paint by previous owner. We have removed the paint and the bricks look great in their natural condition. We seem to have a lot of mortar dust (not sure if that is the proper term). My husband thinks we need to seal it with a brick sealant. However, I have read that historic brick is not good when sealed because it needs to not have moisture trapped within the brick. Any suggestions on how to care for this beautiful original part of our home? It is not a working chimney- used to be connected to a wood burning stove. Now we just have a flue cover over the hole. Maybe eventually we will connect something to it- but for now, I just love the original brick. Any advice would be appreciated.