Quick Mortise With a Hand Drill and Forstner Bits

[Immortan D]

This is about drilling a quick mortise on a finished piece, in order to install hardware, using a hand drill and a Forstner bit. Of course a woodworking router or hand tools will get the job done too, YMMV.

I've seen this question asked a couple of times on these forums, and since I had to do it again during the weekend, I figured I could explain my process here for those who may take advantage of it.

Required Tools: Drill press, hand drill, Forstner bit, wax, chisels, 3/4" MDF, scrap material.

Steps:

1) Determine Forstner bit size and cut depth: Using your drill press, lay out your hardware and make a test cut on a piece of scrap to determine the right size of the fortsner bit, the location of required holes and the depth of cut. Test your hardware until you get a nice fit. Then set and lock a depth gauge for future reference when drilling on your piece. Make sure the mortise won't interfere with the screw locations.

Important: If you're about to drill a very shallow mortise, you may consider setting your depth gauge with your template (see next step) applied to the test piece: once you drilled your template position it over the mortise on your test piece and grab that depth instead.

2) Drill your template: Grab a piece of 3/4" MDF, reference a corner to your piece (e.g. top and left), and again lay out your hardware and using your drill press make the holes all the way thru.

3) Attach your template to the piece: align the reference corner of your template to your piece and clamp it making sure it won't move:

 

4) Make the mortise: I always wax the sides of my forstner bit before starting the cut, this seems to help a bit with over heating by reducing the friction with the MDF template. Drill small amounts on each hole in sequence. Do not drive at full speed and at all times watch for over heating. I found out that slightly rocking the drill up and down while drilling makes the process go smoother.

Once you're about half the required depth you may remove your template and continue the drilling sequence until you reach the desired depth. If you've set your depth taking the template into consideration (see the end of step 1), then leave the template in position until you're finished drilling.

5) Final touches: Using your chisels chop the necessary cuts to merge the holes into one mortise and you're done!

 

 

 

[Isaac]

Just to be clear, you are drilling these with a hand drill? I can see this working when the slot you need allows you to make two distinct circles like this. Anything thoughts when you need something where the circles overlap substantially? My issue is with the bit slipping into the first hole when you attempt to drill the second. 

[Immortan D]

19 minutes ago, Isaac Gaetz said:

Just to be clear, you are drilling these with a hand drill? I can see this working when the slot you need allows you to make two distinct circles like this. Anything thoughts when you need something where the circles overlap substantially? My issue is with the bit slipping into the first hole when you attempt to drill the second. 

Yes, I'm using a hand drill (a power drill). You have to start the hole really slow and hold your drill with both hands. If the holes are way too close to each other you may need a template with a single hole and keep moving the template as you drill each hole... I don't think that's going to be a practical or accurate solution though, I'd use a router instead in such case or drill more spaced holes and then use a chisel to merge them..