forstner bit skills

[David Wadstrup]

Hello,

I'm primarily a hand tool user. Except when it comes to drilling. I need to drill quite a few large diameter and deep hols in some hard maple. Holes all the way up to 2" in diameter and 4" deep. Mostly around 3/4" diameter, though. I'll be purchasing some new Forstner bits for the project. I've never used Forstners before. I understand that they are usually meant for a drill press. I do not have a drill press. I do, though, have a 1/2" hand drill with a hand grip. Do you think I'd be able to use the Forstners with this drill? What would you recommend? I suppose I could try to borrow a friend's drill press if necessary. I'd rather not, though. What is your advice?

Thanks,

David

[Chen-Tin Tsai]

I don't know about the 2" ones, but I've used a corded drill to drill 1" holes with a forstner bit. It wasn't too bad, but it wasn't easy, either. I tried it with my cordless 18V Milwaukee and it drained the battery after 2 holes. I'd say go slow and try it out. Worst that could happen is you end up borrowing your friend's drill press (which does make it much easier).

[Chris True]

Forstners are pretty miserable in a hand drill, they take a lot of feed pressure to cut properly. For the smaller holes you'd be better off with a spade bit in a hand drill, a new sharp one cuts pretty clean holes. For the bigger holes maybe a hole saw although 4" deep may be a problem and if it isn't a through hole the hole saw won't work.

[Johnny Kleso]

If you have a slow speed drill 650 rpm you can do it I think..
Dont try it with a 1500+ rpm drill and the 2" bit :)

You might do better with a brace and bit for holes that large or the new style bits

WOOD SELFEED DRILL BITS
http://www.amazon.com/s/?ie=UTF8&keywords=self+feed+drill+bit&tag=googhydr-20&index=tools&hvadid=3667726105&ref=pd_sl_7xrw81wfre_b

175467

[Andrae Covington]

I highly recommend making a guide by using the bit to drill a through hole in a scrap piece. Then securely clamp the guide hole onto your workpiece where you want to drill. Without something to hold the bit in place as you start the drill, it will dance across the surface like Fred Astaire, only without any grace. At least that was my experience, but maybe you are butch enough to resist the torque of a 2" forstner bit. I used a corded Ryobi hammer drill (with the hammer feature turned off).

175484

edit: Oh yeah, I briefly tried using the forstner in a hand brace. I think seven years per hole would be a reasonable estimate.:rolleyes:

[Terry Beadle]

I agree with Andrae Covington. Make a jig and it will save your hands and arms while increasing your accuracy. Also for the big 2 inch holes, make a series of jig holes starting at about 3/4, then 1 1/4 and then 2 inch, you can creep up on the big holes and not put so much pressure on your hands and the drill. The jig hole will keep the bit centered. I'd use some 5 quarter stock for the jig if you have it.

Another tip is to start the bit very litely. By that I mean let the tip establish the center point very gently then proceed slowly until you have about 1/8th inch depth and then go deeper at a reasonable speed. What's reasonable speed.... let the bit do the cutting gently. Don't force it. I'm ham handed so this tip may not be for you but I've sure noted my drilling, even on my drill press, has shown better results because of it.


I've seen bench top drill presses for less than $50 on Craigs List.... something to think about.

[Eric Brown]

Another thing that helps with Forstners is to use a vacuum. It not only clears the hole but reduces the chance of the bit overheating.
Problem with all Forstners (except the very first patented style - very rare) is that they have a split ring to aid in chip removal and heat reduction. The split however tends to catch on the wood if not held perpendicular to the surface.

Another option is the Irwin solid center pattern of brace bits. They are quite common up to 1".
I would not suggest Russell Jennings touble twist bits with the double thread screw. They have a difficult time with hard maple.
The adjustable augers would also work except the hole will be much rougher and not as straight.

Have fun. Eric

[David Epperson]

I'm thinking that the biggest issue you'll run into with using a hand drill is going to be keeping the holes straight. You might look at using a hole saw of the same diameter to cut a guide, and clean that out with the Forstner bit, repeat as needed to get the depth. The straight walls of the hole saw will help keep the cut straight.

[harry strasil]

I used a 13/16 forstner bit to drill 39 dog holes in my New Oak Workbench Top and 36 in the Apron, fortunately I have a portable drill press from my Blacksmith shop. I might suggest buying one of small bench top drill presses that you can swivel around and lower the top and use that to drill your holes, and clamp it to the work if it's a large piece.
A blacksmith friend of mine used the benchtop drill press method to drill some 1 1/8 holes in a large sheet of 1 inch plate a couple of years ago, so I know it works.

[Prashun Patel]

IMHO, the easiest is to use a drill press here. Very low speed, and keep retracting the bit to keep it cool. It'll be a challenge - even with a jig - to keep a hand drill 90 to the surface.

[Jim Koepke]

Much good advice above. In my opinion, the best is to use a drill press and low speed.

In my own work, I have used forstner bits in a eggbeater. First a guide was drilled with an auger bit of the same size. This would be difficult for the larger sizes.

jtk

[harry strasil]

My take on pre drilling is to start the hole with the right size forstner bit down enough to be a guide and then drill a slightly smaller hole, then ream out the excess with the forstner bit if doing it by hand, forstner bits are notorious for being hard to get to cut by hand, I have a couple of the old ones with the tapered shanks, and this way doing the reaming of just a little will be the easiest and most accurate way. FWIW