# softening a drilled hole edge



## dickhob (Jul 12, 2012)

I need to drill a lot (100's) of 7/16 holes in 1/8 in birds eye maple. I'm planning on buying and using a brad point drill bit for the holes to minimize tear out. I THINK his is the best bit, but if someone has a better idea I'm open to suggestions.

The main problem I'm trying to deal with is a way to soften the edges (top and bottom) of the drilled hole. I've tried a 1/2 counter sink bit and it does ok, but there's still a pretty rough edge. I've tried sanding, but that is really going to take some time to do it right.

I don't think they make a roundover router bit that is that small or could be used safely on that tight of a hole.

I've got to stain the finished area with a lightest brown stain. I'm afraid if I don't get the edges right, I'll end up with board and a bunch of dark rings.

So the problem is two fold- how do I get a softened edge that is both smooth to the touch and that will take a stain?? 

Anyone have any ideas of what/how to best approach this?

Thanks
Dick


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## Dave Paine (May 30, 2012)

I can recommend a better bit that a brad point bit.

The Colt Maxi-Cut will give you the cleanest holes with least effort.

I have these for drilling pepper mill blanks and love them.

http://www.packardwoodworks.com/Mer...e=packard&Category_Code=drilling-bits-maxicut

You might want to try these out to see if the cut line will be sharp enough to avoid the need to soften the ends.

If you do need to soften the ends, you need a large "ball" shaped sanding disk. I am not sure if such a thing exists, you may have to make one.


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## Alchymist (Jan 2, 2011)

A good forstner bit will make a clean cut, if further softening is needed, perhaps:
http://drillsandcutters.com/dulsd5doublecut.aspx


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## cabinetman (Jul 5, 2007)

Abrasive stones for a drill/drill press like these might give you an edge you'll like. For a clean hole, I would use a carbide tipped Forstner bit.








 







.


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## dickhob (Jul 12, 2012)

*Great ideas*

Thanks Guys. That's what I was looking for. 

I usually associate a forstner bit with drilling all the way through something, but I'll certainly give it a try.

The burrs sound like the way to go, but I need to get some.

I've got a round stone. Seems like it might be too fine, but again, it's certainly worth a try.

Great help.
Dick


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## GeorgeC (Jul 30, 2008)

I have some round "stone bits" that fit my drill. These can be used on metal or wood. I have tried to google it but do not know what to call them. I also do not remember where I got them years ago.

A round end mill for a drill would also work.

George


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## BigJoe16 (Feb 20, 2012)

You could try a rotary rasp. I use these on my lathe for rounding over edges and opening the faces on fishing lures i make. I couldnt tell you where to get them though. I got mine at an estate sale.


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## Leo G (Oct 16, 2006)

They make a nice router bit for doing what you want. Look up brass bearing roundover. Or just go here.

http://www.mlcswoodworking.com/shopsite_sc/store/html/smarthtml/pages/bit_brass.html


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## Alchymist (Jan 2, 2011)

BigJoe16 said:


> You could try a rotary rasp. I use these on my lathe for rounding over edges and opening the faces on fishing lures i make. I couldnt tell you where to get them though. I got mine at an estate sale.


See post #3. :smile:


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## dickhob (Jul 12, 2012)

Thanks Leo, I didn't think they made anything that small. I ordered the 1/16 roundover. Will let you know how it works out.


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## BigJoe16 (Feb 20, 2012)

Here is a pic of some of my rotary rasps.


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## Dave Paine (May 30, 2012)

If the 1/6in roundover does not work out, Lee Valley just added carving burrs to their site.

Some are 13/16in dia, so potentially the right size to soften. One a ball end, one a taper.

http://www.leevalley.com/US/wood/page.aspx?p=69808&cat=51&ap=1


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## Leo G (Oct 16, 2006)

dickhob said:


> Thanks Leo, I didn't think they made anything that small. I ordered the 1/16 roundover. Will let you know how it works out.


I have the 1/8 myself and it is a nice size for breaking edges. The 1/16" might be harder to setup because it's size is so small. I was thinking about ordering the kit after I saw they have a chamfer in it now.


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## rrich (Jun 24, 2009)

Cut a bunch of sandpaper squares about 3/4" square. Put a hole in the center of each square and force a machine screw through the hole. Put 4 to 6 sandpaper squares on the screw and tighten a nut against the sandpaper. Chuck the assembly in a portable drill. Set the drill to turn in reverse. A quick touch of the sandpaper spinning in the drill should smooth the edges of each hole.

Experiment with screw sizes to find he appropriate size. I would guess that a #10 (3/16") by 32 would be the correct size. (1/4 x 20 has a head 3/8" and is probably too big.)

One other thing. I would use wet or dry paper as it has a stronger backing.


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## dickhob (Jul 12, 2012)

Holly smokes, I've never gotten this many replies to a question- all great.

This is what I ended up ordering






I was looking for a flap sander type solution, but everything was just too big. DIY wins out every time if you can just get your head around the problem properly. I've got a feeling this is going to be the best and cheapest solution. Of course I had to go spend $20 first to get to a 20-cent solution! I tend to to that more than I want to admit.

Keep em coming, if there are any more ideas. This is great.
Thanks
Dick


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## jschaben (Apr 1, 2010)

I've used a small "V" router bit in the drill press. Run on the highest speed, still nowhere near router speed but works fine.:smile:
Ball will give you a cove edge. V bit will give you a champfer and a point roundover will give you just that.


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## jigs-n-fixtures (Apr 28, 2012)

Eagle makes plunge round over bits that would work well.

Sent from my iPhone using Wood Forum


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