I need to change a couple of night latches. I bought a 60mm backset one to replace a 60mm latch and guess what? they're just a bit different. I also have a door that has a 40mm backset but can't easily be opened and could use a 60 instead. So the problem, in each case, is how to drill a hole off centre from the previous one.
In the first case, I could probably enlarge the hole on one side with a rasp. Not very elegant, but it would all be covered by the fittings. For the other, the point of a spade drill would be boring into fresh timber, but it will probably not like clunking against the old hole as it turns.
So does anyone have a tried and trusted solution to this situation? I have thought of using a two-part filler to fill the old hole then treating the whole thing as new. Alternatively, clamping some timber to the face of the door and drilling through that first to constrain deflection of the drill. Would a Forstner bit be any help for this? (never used one but they look like they might)
I'm sure I can't be the first person to have this problem, so any (sensible) suggestions gratefully received.
Cheers