smoothing the back of a lock mortice

[JohnD]

I am not very good at woodwork.

A long time ago I fitted a large mortice lock to my hardwood front door, drilling 5/8" holes and chiselling out the remainder.

I recently fitted a new lock, and although it is nominally the same model, the case is made differently and is a bit deeper, it is riding on the back of the hole. This is too deep for my chisels to get a cutting angle on it. I have tried raking the chisels forcefully down the back of the hole, but the wood is very hard and I am just scraping a bit of dust off, and chipping the edge off the chisels.

Is there a better way?

 

[Jasonb]

A Swan-neck chisel is the tool for the job . If its too deep for a mad bit you can just use a long flat bit to chew out the waste.

Jason

 

[Burnerman]

Use a flat bit of the correct diameter and cut the timber away...if you overdo it at some points it doesn't matter. John