Drilling partially overlapping holes

GMM

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Jun 21, 2012, 7:25:52 PM6/21/12

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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

The Natural Philosopher

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Jun 21, 2012, 9:20:46 PM6/21/12

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fill old holes with car body filler.

--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.

John Rumm

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Jun 21, 2012, 9:25:49 PM6/21/12

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On 22/06/2012 00:25, GMM wrote:
> 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.

That is not too bad if the new hole is mostly contained, however there
is risk of it splitting out if you have not got much wood around the
point of the spade.

> 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

Cutting a wood plug (square with the corners whittled off can be good
enoug) to fit the old hole can work.

> 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)

This technique works best with a hole saw I find. Its relatively easy to
constrain them when drilling part wood and part nothing.

The decorating details I used on this book case were done with a holesaw
in a pillar drill - however the ply template would do just as well (in
fact probably better than on my cheap and sloppy pillar drill!)

http://wiki.diyfaq.org.uk/index.php?title=Small_bookcase

--
Cheers,

John.

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harry

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Jun 22, 2012, 2:37:45 AM6/22/12

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Small sharp chisel. Or make up a wood plug and glue in old hole and
redrill.

NT

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Jun 22, 2012, 3:46:35 AM6/22/12

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On Jun 22, 12:25 am, GMM <Han...@dsl.pipex.com> wrote:

Do yourself a favour and get a latch that fits. Lot easier than
plugging and redrilling, and filling.

NT

Reentrant

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Jun 22, 2012, 5:46:48 AM6/22/12

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On 22/06/2012 00:25, GMM wrote:

>... 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.

A Forstner bit wouldn't mind - ideal for overlapping holes.

--
Reentrant

dennis@home

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Jun 22, 2012, 8:08:37 AM6/22/12

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"GMM" <Han...@dsl.pipex.com> wrote in message
news:42331e18-ca15-4c2b...@w24g2000vby.googlegroups.com...

Its easy despite what people say.

Clamp a scrap block of wood to the door, drill trough it.
Its easier with a hole saw or a forsner bit as they are guided by the hole
once started.

However if you don't fill the hole the door will be weakened some more.

GMM

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Jun 23, 2012, 10:40:24 AM6/23/12

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Excellent advice as ever, Mr Rumm - the only tool I didn't think of
was a hole saw but now you raise it, it's clearly the best thing, as a
piece of ply or something would effectively keep it in position, along
with the pilot/arbour, where there's some wood in the centre.

GMM

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Jun 23, 2012, 10:44:57 AM6/23/12

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Kinda hard to get a 60mm backset that fits the same as a 40mm one,
since the whole point is to bring the thing away from the frame as
much as possible. I can't imagine what the person who fitted the 40mm
set there was thinking, as the door is set behind brick on our
sideway. Having sued the wrong size, he then spaced the whole thing
back (so it could be opened from outside) by an inch or so, so the
door always looks like it's partway open.

So far as the other one is concerned, it seems that a BS marked
security lock is just different enough from an old low security latch
as to not line up. If I put a non-BS one on there, it wouldn't really
be worth bothering to change it.....

GMM

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Jun 23, 2012, 10:47:00 AM6/23/12

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On Jun 22, 1:08 pm, "dennis@home" <den...@killspam.kicks-ass.net>
wrote:

Definitely a case for setting a wood block in the hole with some 2-
part filler, then covering with a finger plate or something if it
doesn't look as good as it should.

GMM

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Jul 2, 2012, 5:34:54 AM7/2/12

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On Jun 22, 2:25 am, John Rumm <see.my.signat...@nowhere.null> wrote:

Just to complete this thread - in case anyone ever finds it (!)

I formed the hole using a hole saw (set up with the template from the
lock packaging) in 9mm MDF, then clamped that to the door and put the
hole saw through, with its pilot drill in fresh air. The MDF guided
the saw and I was through in seconds (with a pause to do the last bit
from the other side. Nice clean hole, smack in the right place.

The only gotcha is alignment - it was trickier than I anticipated
ensuring I was in line vertically with the old hole, as it had been
hacked out rather than drilled. I did take the precaution of drawing
vertical and horizontal lines to the hole centre before I cut the MDF,
which helped, a bit.

Of course, fitting the latch onto the tab from the lock that sticks
through the door took a bit of swearing (and a bit of filing) but then
I find it always does, before slipping in as though there was never
any problem.....

Thanks for all advice!

Rick Hughes

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Jul 2, 2012, 9:03:35 AM7/2/12

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On 22/06/2012 00:25, GMM wrote:

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
>

Forstner bit is OK ... but I would not wan to use one of those outside
of a drill press.

I would clamp on a piece of wood to give you a new face and then use a
hole saw, take your time, very light pressure