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05/08/2009 6:44 PM

Sharpening a Forstner bit?

I have a large (3.5") Forstner bit that has lost its edge. Is there a
DIY way to sharpen it, or is this something that must be done by a
professional? It looks like I might be able to hone the teeth and the
knife edges, but I'd like to hear what you folks have to say about it
before I do.

Thanks.

Lynn Willis


This topic has 12 replies

DN

David Nebenzahl

in reply to "[email protected]" on 05/08/2009 6:44 PM

06/08/2009 11:14 AM

On 8/5/2009 8:48 PM jo4hn spake thus:

> Highland Hdwe has one [instruction page] at
> http://www.google.com/search?q=forstner+bit+sharpening [...]

That seems to be the Google search page you used to find it. The
Highland page is actually at
http://www.highlandwoodworking.com/index.asp?PageAction=Custom&ID=101


--
Found--the gene that causes belief in genetic determinism

Pd

"Pat"

in reply to "[email protected]" on 05/08/2009 6:44 PM

05/08/2009 7:16 PM


<[email protected]> wrote in message
news:58da3ebd-ca59-4193-b423-5489422b7d93@h21g2000yqa.googlegroups.com...
>I have a large (3.5") Forstner bit that has lost its edge. Is there a
> DIY way to sharpen it, or is this something that must be done by a
> professional? It looks like I might be able to hone the teeth and the
> knife edges, but I'd like to hear what you folks have to say about it
> before I do.
>
> Thanks.
>
> Lynn Willis

I use a file on mine all the time.

jj

jo4hn

in reply to "[email protected]" on 05/08/2009 6:44 PM

05/08/2009 8:48 PM

[email protected] wrote:
> I have a large (3.5") Forstner bit that has lost its edge. Is there a
> DIY way to sharpen it, or is this something that must be done by a
> professional? It looks like I might be able to hone the teeth and the
> knife edges, but I'd like to hear what you folks have to say about it
> before I do.
>
> Thanks.
>
> Lynn Willis

Here's an instruction page that I printed out years ago:
http://wwch.org/techdata/forstner_bit_speeds.jpg

Highland Hdwe has one at
http://www.google.com/search?q=forstner+bit+sharpening&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a
or better yet http://tinyurl.com/kvresl

mahalo,
jo4hn

MH

"Martin H. Eastburn"

in reply to "[email protected]" on 05/08/2009 6:44 PM

06/08/2009 8:59 PM

That is a fast and heavy way - I like a cone stone myself.
Use a curve to sharpen a curve.

What I see with the Dremel method - while fast and 'easy' - it can
cut notches and make a wavy line if one isn't perfect in the use.

A stone can be used wrong, but does less in a second to clean up later.

Martin

Tom Veatch wrote:
>
> http://www.highlandwoodworking.com/index.asp?PageAction=Custom&ID=101
>
> should open a white paper on the subject by Highland Woodworking.
>
> If it doesn't, go to http://www.highlandwoodworking.com
> scroll to the bottom of the listing on the left under "More Info" and
> click on the link "Woodworking Tips Map".
> In the right column near the bottom of the page under "Woodworking
> Library", click on the link "Sharpening Forstner Bits"
>
> Tom Veatch
> Wichita, KS
> USA
>
>

Uu

"Upscale"

in reply to "[email protected]" on 05/08/2009 6:44 PM

06/08/2009 3:37 AM


<[email protected]> wrote in message
> I have a large (3.5") Forstner bit that has lost its edge. Is there a
> DIY way to sharpen it, or is this something that must be done by a
> professional?

Guessing yours doesn't have a carbide inserts.
http://www.youtube.com/watch?v=bt4weRZs0HM


JG

"Jeff Gorman"

in reply to "[email protected]" on 05/08/2009 6:44 PM

06/08/2009 8:12 AM


<[email protected]> wrote

>I have a large (3.5") Forstner bit that has lost its edge. Is there a
> DIY way to sharpen it, or is this something that must be done by a
> professional? It looks like I might be able to hone the teeth and the
> knife edges, but I'd like to hear what you folks have to say about it
> before I do.

I recall that some sixty-five years ago, ie before diamond tools and
suchlike, my revered woodwork teacher told me (with some satisfaction) how
he had managed to sharpen the peripheral edge with a triangular engineer's
scraper.

I've never tried it, but I imagine it would get into the corners more easily
than the rotary and other tools.

Jeff

--
Jeff Gorman, West Yorkshire, UK
email : Username is amgron
ISP is clara.co.uk
www.amgron.clara.net

jj

jo4hn

in reply to "[email protected]" on 05/08/2009 6:44 PM

06/08/2009 3:11 PM

David Nebenzahl wrote:
> On 8/5/2009 8:48 PM jo4hn spake thus:
>
>> Highland Hdwe has one [instruction page] at
>> http://www.google.com/search?q=forstner+bit+sharpening [...]
>
> That seems to be the Google search page you used to find it. The
> Highland page is actually at
> http://www.highlandwoodworking.com/index.asp?PageAction=Custom&ID=101
>
>
oopsie. Thanks.

TT

Tanus

in reply to "[email protected]" on 05/08/2009 6:44 PM

06/08/2009 8:55 PM

[email protected] wrote:
> I have a large (3.5") Forstner bit that has lost its edge. Is there a
> DIY way to sharpen it, or is this something that must be done by a
> professional? It looks like I might be able to hone the teeth and the
> knife edges, but I'd like to hear what you folks have to say about it
> before I do.
>
> Thanks.
>
> Lynn Willis

I've never sharpened a Forstner.

However, I've sharpened a lot of other tools in the shop. Most of them
successfully. One of the things that has helped me with my approach
towards sharpening is Leonard Lee's book "The Complete Guide to
Sharpening". It's a bit of a heavy read, but virtually anything that can
be sharpened is covered in that book. I recommend it to anyone who ever
thinks they'll have to sharpen any woodworking tools especially, but
most tools in general.

http://www.leevalley.com/wood/page.aspx?c=1&p=32991&cat=1,43072,43091

Tanus

n

in reply to "[email protected]" on 05/08/2009 6:44 PM

06/08/2009 12:28 AM

On Wed, 5 Aug 2009 18:44:27 -0700 (PDT), "[email protected]"
<[email protected]> wrote:

>I have a large (3.5") Forstner bit that has lost its edge. Is there a
>DIY way to sharpen it, or is this something that must be done by a
>professional? It looks like I might be able to hone the teeth and the
>knife edges, but I'd like to hear what you folks have to say about it
>before I do.
>
>Thanks.
>
>Lynn Willis

I've not (yet) needed to sharpen a Forstner bit, but Rockler has a kit
of sharpening tools and instructions for $18:
http://www.rockler.com/product.cfm?page=22012

John

TV

Tom Veatch

in reply to "[email protected]" on 05/08/2009 6:44 PM

05/08/2009 11:38 PM



http://www.highlandwoodworking.com/index.asp?PageAction=Custom&ID=101

should open a white paper on the subject by Highland Woodworking.

If it doesn't, go to http://www.highlandwoodworking.com
scroll to the bottom of the listing on the left under "More Info" and
click on the link "Woodworking Tips Map".
In the right column near the bottom of the page under "Woodworking
Library", click on the link "Sharpening Forstner Bits"

Tom Veatch
Wichita, KS
USA

Pn

Phisherman

in reply to "[email protected]" on 05/08/2009 6:44 PM

07/08/2009 5:57 AM

On Wed, 5 Aug 2009 18:44:27 -0700 (PDT), "[email protected]"
<[email protected]> wrote:

>I have a large (3.5") Forstner bit that has lost its edge. Is there a
>DIY way to sharpen it, or is this something that must be done by a
>professional? It looks like I might be able to hone the teeth and the
>knife edges, but I'd like to hear what you folks have to say about it
>before I do.
>
>Thanks.
>
>Lynn Willis


Sure it is possible and sharpening is a good skill for woodworkers.
Natural lighting, magnification, and patience helps.

LH

"Lew Hodgett"

in reply to "[email protected]" on 05/08/2009 6:44 PM

06/08/2009 2:30 AM

<[email protected]> wrote:

>I have a large (3.5") Forstner bit that has lost its edge. Is there a
> DIY way to sharpen it, or is this something that must be done by a
> professional? It looks like I might be able to hone the teeth and
> the
> knife edges, but I'd like to hear what you folks have to say about
> it
> before I do.

Even an el-cheapo 3.5" Forstner bit is in the $40-$50 range.

Quality bits are more.

Willing to make that bet, you screw it up, you replace it, or would
you rather have a pro do it?

Lew



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