Drilling a hole in nothing?

[jedmc571]

Hello everyone, first post here!

Been lurking for a while, and actually have a question that only Festool owners could probably answer?

I have 14 x 36mm MDF interior doors with badly fitted tubular latches. I have new latches by a company here in the UK called Union. They produce the Fastlatch which is an interference fit latch with no fixable face plate.https://www.uniononline.co.uk/en/site/union-online/union-fastlatch/
I've fitted one, and they do need an accurate hole, also the MDF gives a too easy fit as it compresses the fibres when being knocked in, that said, the spindle in the handles would prevent it moving

My intention is to remove the old ones which leaves an existing 25mm hole which I know isn't drilled accurate, then drill it out to 28mm, glue in a dowel, and then redrill my 25mm hole again, and the solid wood being a better medium to fix into.

I actually bought a jig to do the job called a Souber DBB. I figured the jig would be more accurate than my current set up which is a modified drilling jig by Wolfcraft, basically 2 legs with springs with a dubious plunge action  [big grin]
I also had to buy extra cutters which is pushing the price up!

The Zobo set has been on my wish list for years, but I tend to buy tools when required, I'm a Maintenance Engineer, but a hobbyist woodworker with an addiction to the black and green  [big grin] The % piece set is available from Amazon UK for £110 and having the 25mm and the 30mm I figured it might be an option? at least I have something i can re-use rather than a £150 jig and cutters which are specific to door locks. My concern here is 30mm only leaves me 3mm either side.

My other concern is setting up a plunge mechanism and essentialy having nothing to plunge in to but trying to take out the extra 5mm required. so making a 28mm hole over a 25mm existing one, and I'm not sure if it will just catch hold and tear it to pieces, or cut like a knife through butter........which is what I'd like!
Does this make any sense?  [huh]

Look forward to your replies

Jed.

 

[Holmz]

On the cheap...

1) use A-hole saw, or zobo bit, to make a hole in some plywood or MDF

2) Imagine yeself Clamping wood to the door.

3) Using that as a guide - drill the new hole.
(32-mm may be a decent size?)

 

[tjbnwi]

What Holmz said, create a drilling guide.

Tom

 

[lwoirhaye]

Drilling a straight hole into the end-grain of a dowel rod is something I am pessimistic about.  Drills tend to wander in end grain.  Even if that is not a problem I don't see the 28mm hole coming out straight with no material in the center.

An easier way to go about it which may or may not be acceptable is to route or chisel out a rectangular hole and fill it with a plate of solid wood, say 1/2" thick.  The 25mm hole can then be drilled in the patch.  If the extant 25mm hole is not close enough to the new hole for the hardware to pass through, the patch can be removed and the hole beneath it can be filed larger where needed using a rat tail rasp or half-round Iwasaki file.  Then glue the patch in.

 

[Holmz]

Drilling a straight hole into the end-grain of a dowel rod is something I am pessimistic about.  Drills tend to wander in end grain.  Even if that is not a problem I don't see the 28mm hole coming out straight with no material in the center.

An easier way to go about it which may or may not be acceptable is to route or chisel out a rectangular hole and fill it with a plate of solid wood, say 1/2" thick.  The 25mm hole can then be drilled in the patch.  If the extant 25mm hole is not close enough to the new hole for the hardware to pass through, the patch can be removed and the hole beneath it can be filed larger where needed using a rat tail rasp or half-round Iwasaki file.  Then glue the patch in.

Good point.

In my case the hole was more like a US lock and not a small Euro one.
So I used a hole saw and that was 1-1-1/2 tall... So I had had a guide most fo the way through and switched around with the second half to the other side.

The Zobo/Forstner would need meat all the way around it, so a 32-mm may be better... I would suggest to test it somehow, or use a small holesaw so it supported by the guide.
Not drilling normal to the surface is the next drama to consider...

 

[semenza]

Hi Jed,

    Welcome to the forum!  [smile]

      How many do you have to drill?

    If you have a plunge router and make a solid jig that can be clamped to the door and the router is solidly attached to the jig, then you could make a slow, well guided plunge.

Seth

 

[Stone Message]

Hi Jed

There is a very simple solution to your problem and it is one that I use a lot.

If you want to put a Forstner style drill overlapping an existing hole start by taking an offcut of anything that is flat, say a piece of ply or MDF as thin as 8 mm but best at about 12 mm thick.

Drill a hole near one end using the larger Forstner that you want to use. Next clamp the piece of wood over the target hole and make sure it is positioned where you want the hole.

Now drill through the template and the drill will not wander at all.

Peter

 

[jedmc571]

Thanks for the replies everyone,
Seems most of yo had the same idea. I don't have enough experience to disagree with anything, so I guess I'll just have a go and see how I get on.

I see merit in a few suggestions......drilling end grain, yeah, that could be problematic? But using a block of wood to fill the gap instead of a dowel makes sense.
The idea most of you suggested was to use a drill guide, I've actually done this with Marcrist tile drills, they sell a template with the different holes to guide the core cutterhttp://www.tilegiant.co.uk/marcrist-pg750x-tile-drilling-guide.html It just never occurred to me to do it with wood  [smile]

If I can just ask one more question..................I'll need to fill the space where the faceplate was on the edge of the door, and I wondered if you would reccommend 2 part filler over a regular wood filler, particularly if it's going to be drilled? Never used the 2 part, so no idea of it's use.

Cheers

Jed

 

[upscale]

If the center of the existing hole lines up with the center of the larger hole you'd like to make, then you need a special arbor hole saw for this exact purpose.
Oops Hole Saw

 

[Holmz]

Thanks for the replies everyone,
Seems most of yo had the same idea. I don't have enough experience to disagree with anything, so I guess I'll just have a go and see how I get on.

...
If I can just ask one more question..................I'll need to fill the space where the faceplate was on the edge of the door, and I wondered if you would reccommend 2 part filler over a regular wood filler, particularly if it's going to be drilled? Never used the 2 part, so no idea of it's use.

Cheers

Jed

Anything... That area will be under compression if there is a new faceplate.
And if no Nee face plate then it just needs to stay in place.
(That said the locks always seem to leave a greasy residue or it is brass polished..)

Popsicle sticks glued down, a wooden plug, bondo, ...

 

[jedmc571]

Quick update,

Using the Jig, I managed to expand the holes with no need for anything else. I then filled the holes with 28mm dowel, bit of 2 part filler, sanded with a combi of Rotex, and RTS, and the finish was very good  [big grin]

And that's where the fun ended  [sad]

I set up the jig again with a 25mm cutter to mortice for the latch, and as suggested, it struggled getting through thee dowel end grain, I would've expected a bit more from the cutter, but it was pretty much done for after 1 hole.
Just to make matters worse, when I put the latch in, it wouldn't hold? I measured the latch at 25.4, but my hole was just shy of 26mm? I drilled another, and the same thing happened! They're interference fit, so the hole needs to be right
I drilled one hole manually with a spade bit........perfect? Turns out the bronze bush that holds the cutter shaft on the jig had play in it, causing the cutter to wander randomly  [mad]

I'm in the process of trying to return the jig and cutter, and in a fit of rage, ordered a set of Zobos from Amazon ready for tomorrow.
I've lost a half day messing around, so hopefully Mr Zobo will get me back on track

So, now I'm devoid of £110 is there anything you'd suggest for their use......drill speed etc, or can I just whoop those bitches straight in  [big grin] [big grin] [big grin] [big grin]

Cheers

Jed.

 

[Holmz]

We'll end grain is tougher, but I zobo'ed a 25-mm hole for a 1" pipe on Sunday, abnd needed to use a file. They are much smoother bore than a spade drill.

A router was suggested earlier.

 

[mwildt]

Ok, keep the template (with slightly larger hole) but could you use a router with a guide bushing instead ?
Might make more progress on end grain than the drill bit.