Can you reparge,remortar old firebrick?

[Bruce L]

Crawled inside arch this morning to clean out ash that had blown to back of combustion chamber,under grates,and noticed that firebrick are loose and chipping away after 10 years of hard firing. Can I just reparge over top,or should I take the bricks out and install new? Thanks

[Bricklayer]

Depends on how bad it is.
Regular fire clay ( mortar) is really only meant to be 3mm thick max.
You may get away with parting it up. And you may not.
Finding a good bond to old firebrick is gonna be tough.
There are castables available for this purpose. But the cost of them might outweigh the price of just putting in new fire brick.
Not sure if you still have my email Bruce. But I am re-bricking my arch this summer and could give you a hand or do it for you.
I’m sure I’ll have lots left over from mine too. I’ve been saving them for years from various jobs.
L

[TapTapTap]

I agree with Bricklayer. Maybe his name means he knows more than most of us about this topic. My thinking is that at best you can parge and relay old firebricks to get through the next season. I did repairs last summer and I'm gearing up to do an entire relining for next season, including new ceramic wool lining. I also have a wrinkle in my rails where hot air blew out and caused the warp. It's best not to get to that point.
Ken