drilling in pine

[John T Barker]

I'm drilling a ton of holes in pine and I am using a brand new forstner drill bit on my drill press. I get tear out on entry. Anything I can do to eliminate this? RPM's? Nothing?
Thanks

[John Lankers]

Interesting, my first guess would have been a dull drill bit but when yours is new and of good quality that eliminates this possibility.
Have you tried starting the cut very slowly to give the spur time to score the perimeter of the hole? If you only had a few holes to drill you could sandwich the workpiece between two sheets of hardboard or scrap to eliminate tearout.

[pat warner]

Would clamp the work before the drill hits it.
And if the cutter is >7/8, I'd drill at <250 rpm.
And it would not hurt to enter slowly, then feed at the cut rate of the tool.

[Keith Westfall]

If it's not clamped somehow, it may move a bit causing a bit of tear out before it gets deep enough to stay in place. (only guessing...)

[John McClanahan]

Even though the bit is new, it sounds like it is not as sharp as it could be.


John

[Lee Schierer]

Take a piece of scrap and bore a hole through it. Then clamp that piece directly over the location for the hole in your finished piece. The scrap piece will prevent any tear out.

[John T Barker]

Appreciate the suggestions. Unfortunately I have to drill 4700 holes so clamping or use of scrap would slow me down too much. I'll try the slow feed...I hate pine.

[Brian Tymchak]

Even though the bit is new, it sounds like it is not as sharp as it could be.


John

My guess as well. Or the entry of the bit to the wood is too fast. Go slow for the bit to cut its first edges.

[Brett Luna]

You might also try starting the hole with the drill running in reverse, allowing the spurs to more gently score the perimeter.

[Bradley Gray]

You could make a pattern with an index hole under each hole you need to drill that fits over a pin in the drill press table.

This holds the work almost as well as a clamp but is much faster.

[Erik Loza]

I don't have a suggestion beyond than what others have posted but am curious. What is the project that requires 4,700 holes?

Erik

[John K Jordan]

I'm drilling a ton of holes in pine and I am using a brand new forstner drill bit on my drill press. I get tear out on entry. Anything I can do to eliminate this? RPM's? Nothing?
Thanks

This may not be practical for a "ton" of holes, but when I want an absolutely clean entry I clamp another piece of wood on top and drill through it. (Another piece on the bottom too if I want a clean exit.)

And make sure the bit is sharp even if new.

I haven't tried this, except on the lathe where tearout was a problem and when chip carving, but I'm wondering if a coat of thinned sander sealer before drilling would help.

JKJ

[william watts]

We do not know what size holes your drilling. My set of LV brad point bits has cutting spurs that are way sharper than my forstner bits, but they are under 1/2". LV my have larger available. You could hold the work steady against a fence if it's shape allows. 4700 holes at 15 seconds per hole equals 19.5 hours

[Frank Pratt]

How about making all the pieces just a little bit thick & then bring them down to final thickness after the holes are drilled, thus removing the torn out layer. Something to try if nothing else works.

[Myk Rian]

You might also try starting the hole with the drill running in reverse, allowing the spurs to more gently score the perimeter.

On a drill press?