Pocket Hole troubleshooting...Experts please weigh in!

[Justin]

Hi all,

Below is a picture of an issue I am having recently.  This is a picture of pocket holes in 3/4 oak.  In a softer wood the issue, let's call it burs, are more pronounced.  I am using a corded drill with up to 3000rpm, I am letting it get up to speed.  I have tried a new bit, drilling slower, drilling faster, etc.  The only thing I can think of is some how I am using the jig incorrectly all of a sudden?  It is ever single hole.  

I spoke with a Kreg rep at a local Woodcraft store event and he said he was having the same issue.  

Help, friends!

[Russ Haynes]

It's not you.  It happens, even at the correct drill speed, with a sharp bit, with dry stock, wet stock, etc.  It has much more to do with the orientation of the holes with respect to the grain of the workpiece being drilled.  When you're drilling holes across the grain you're going to get more burring/flashing/fingers/whatever you want to call them.  I've found no easy way to avoid it over the course of drilling probably thousands of pocket holes now.  I have several suggestions  First, the expensive one -- purchase a "sanding star" and use it to clean up the holes before finish and assembly.  Second, the "redneck" version (my preferred method) is to glue a piece of 150-grit sandpaper to a round pencil, chuck the pencil into your drill and clean up the holes afterward.  Third, use a cylindrical rasp to clean them up.  Or four, if' you're plugging the holes later, just leave 'em, then sand it all down later once your plugs are in.

[Justin]

Thanks Russ,

I've been using a sharp chisel to knock it off. I'll try some of your methods now, thanks.  Yay, I'm not crazy! 

[Russ Haynes]

Of course you're crazy -- you have voluntarily chosen to associate with the other sawdust fanatics here!  You gotta be careful with the sharp chisel though -- one slip and your holes aren't ovals anymore, they have little gouges that won't get covered up by a plug.  And when you're cutting cross grain, like you would be in the workpiece you posted, you can get tearout and make the problem worse by taking a chip out of the workpiece surrounding the hole.  That's not easily covered up with a plug.  Easiest method really is to push them over into the hole with a sanding block, then crush them into the pocket when you insert a plug.  They actually help get the plug in nice and tight and the only material removal that takes place is when you sand down the plug.  It ensures that you get a nice tight joint around the plug and that the surface of the workpiece around the pocket is uniform and unblemished.   But if you're a "give-me-the-knife" type of woodworker (plenty out there and nothing wrong with it -- I myself think there are few types of joinery problems that can't be fixed by cutting it too small then working it out with a ridiculously sharp instrument), accept it, but use the rasp instead.  You'll satisfy your craving and safely clean up the pockets with less risk of killing a workpiece. Good luck!

[Justin]

Thanks Russ!

[KregCS]

Justin,

 

Russ is right in that drilling across grain like you are in the picture will increase the amount of tear out you are experiencing.  However, there are a few things you can do to minimize the amount you see.  First thing is to make sure that you are getting enough clamping pressure on your piece.  If your material moves some it can increase this.  The other items that can increase this it appears that you have addressed with the drill speed and your dull bit.  If you have any thing else come up please let us know and we would be more than happy to assist you. 

[Jay Boutwell]

Justin, from looking at what you have shown I would also suspect that since this appears to be coated with a lacquer or poly finish of some kind, that some of the wood remains at the rim of the hole because of the finish.  The finish is like a piece of scotch tape that did not cut free of the hole and like a glue it holds on to wood fibers.

If you notice the fibers are on the side of the hole where the bit will be lifting upwards on the cut and not downward as it would be on the other side.  The rotation of the bit will pull the wood fibers down on the clean side pulling the fibers downwards and cutting them free of the surface.  On the side where the fibers are, the bit is lifting upward on the fibers and not cutting them free.  You will notice on most wood holes bored the most uncut wood fibers will be on the the side as shown. 

[Derek Gould]

I've noticed the same thing; I assumed it was typical to have to do a little bit of cleanup on the hole after drilling. In this case it looks like most of the burrs are from the surface, probably held together by the existing finish. A light sanding will take care of them; if you're plugging the holes you're going to be sanding anyway.

[Raymond Buitron]

Would applying a strip of masking tape over the area to be drilled help?? Maybe this would reduce some of the tearout...