Removing the old mortar is probably the hardest and most time-consuming part of the job.
He pulled it at an angle, and was rewarded with a shower of old mortar from above.
You didn't want to lose-artillery, even a little old mortar.
The stones were solid, but between them was old mortar, which crumbled easily.
"The new mortar looks white next to the old mortar, but it's just clean."
One worker was using a chisel to extract old mortar from a buttress.
Work carefully to remove the old mortar without damaging the surrounding brick.
Consultants devoted much time to testing the old mortar and coming up with a recipe that matched it.
This process involves replacing old mortar in order to better bind the bricks together.
Both the modern mortar and the older mortar were used for high angle fire.