Hand drill problem

[SRoper]

I have a rather old (1970s?) Black and Decker corded drill. Often when I am drilling a larger sized hole in wood, the bit grabs and goes all the way in like a corkscrew without properly boring a hole. It's pretty annoying because this drill has no reverse. How do I prevent this? Is there a problem with my technique?

 

[Southern Presbyterian]

Sounds like the bit(s) need to be sharpened or replaced. Is it one bit in particular, or all bits?

 

[sevenzedek]

I would agree with James. In addition to his advice, I have found something else that helps. What has helped me, in the past, is to put the drill on the high speed and apply a light amount of pressure toward the hole being drilled.

 

[VictorBravo]

What kind of bit are you using? Some random thoughts:

The "corkscrew" effect sounds odd if you are using an ordinary spade bit. If that is what you are using, basically make sure it is sharp and don't push too hard.

If it is a forstner-style bit, same thing, make sure it is sharp and you don't need to push too hard.

If you find you have to push hard, and the bit is sharp, try pulling it out before going all the way through to clear the hole of shavings.

And if you are using what is called a "self-feeding bit," you might try removing the feed screw after the hole is started.

 

[VictorBravo]

Also, if you want the exit part of the hole to not be all mangled (not a big deal for framing work, but maybe important for finish work) clamp another piece of wood over where the drill will exit. It helps keep the edges from tearing and stops the bit from jumping through suddenly when it nears exit point.

 

[SRoper]

I am using twist drill bits. I guess "larger" is relative. It happens around 5/16" and above. I have it happen with brand new bits from Dewalt, so I assume they are sharp.

 

[Southern Presbyterian]

My next guess would be that you need to back off on the amount of pressure that you apply during the drilling process. The softer the wood you drill, the less pressure you should need. But there is also the possibility that your drill is not developing enough RPMs. Perhaps a new set of brushes is in order?

 

[SRoper]

Thanks for the tips. I didn't realize how much I'm a part of our disposable culture. I always thought of drill bits as disposable, and I never considered replacing the brushes on something like a hand drill.

 

[malum in se]

Sometimes this happens even with a good drill and sharp bits, it's just more of a pain when the drill doesn't have reverse. As others have said sometimes less pressure does help though.

 

[Mushroom]

Don't use 'Ship's auger' bits if you want to avoid this. Twist bits can do the same thing, especially in softer wood. You can avoid it by using an in and out action, pulling out before it 'bites' and clearing the flutes of shavings. Forstners are best for clean holes with flat bottoms, and they don't grab. Spur point bits do a pretty good job of avoid grabbing, too. Spade bits don't grab, but they're not very good for accuracy or clean holes. Irwin makes some tri-flute larger bits that do pretty nicely, but the in and out action is necessary.

 

[SRoper]

Thanks, Brad. I definitely try using an in and out action, if only to clear the shavings. It's just when it grabs it is only a few rotations before the bit is all the way in. I will try some of the different types of bits you suggested.

A correction to my earlier post: I meant 3/16" and larger, not 5/16". My drill only has a 1/4" chuck.