Fireplace repair to the firebox (wood)

My fireplace is 80+ years old. The bricks and mortar in the rear of the fireplace are badly pitted and deeply eroded. I believe that the fireplace is no longer safe. My questions are:

1. Can I dig out the old bricks and replace them? If so, any idea where to purchase bricks for a fireplace.

2. Do I need special mortar that resists intense heat? If so, where can I purchase it?

3. Can I just fill in the deep scars and pits with a protective motar, and then adhere some protective facade? (Heat reflector?)

Thanks for any and all information on this topic.

George Kopf

 

Before beginning your project, I recommend an inspection by a Certified Chimney Specialist. There may be more problems with the chimney than meets the eye.
http://www.csia.org/homeowners.html

"The firebox of course takes the brunt of the fires' heat and it requires some special attention. The firebrick can take the heat pretty well, but the fireclay joints will fail in time from the constant expansion and contraction. In a fireplace without a chimney cover, the rain water will also pool on the smoke shelf, mix with the soot behind the damper, and form an acidic slurry that seeps into the fireback destroying the mortar joints. These joints must be kept in good repair with a high temperature refractory mortar to insure the fire is contained. " Fireplaces. Chimney Safety Institute of America. Retrieved 29 May 2002. http://www.csia.org/home/fireplce.html

Refractory brick and mortar can be found at a local brick yard or home center or building supply.