Official Luthiers Forum!

I have been trying to find suitable countersink bits to countersink the bridge properly but I don't want to sink almost 40 dollars on a Stewmac tool that does only that. I ordered a countersink from Enco but I got confused with their countersink angle and it turns out that while 60 degree is great for Fender pickguard it's too steep for bridge holes. The problem is that I needed to jump through a ton of hoop to order from Enco and they insist on shipping it express, so that means 30 dollars shipping for a 5 dollar part. I tried local tool dealers and they don't even know what a countersink is much less provide the correct one so in desperation I bought one of those drill/countersink thing that also turns out to be a 60 degree countersink (and sadly drilled it into a bridge). I tried ordering through McMaster Carr and they said in an email that due to ever complex export regulations (which only consist of filling out one form) they will only deal with a few overseas customers. Caswell plating only accept wire transfer which costs 15 dollars.

So can someone do me a favor? I will order a correct countersink from ENCO or other tool dealers, send it to you then you forward it to me in a first class envelope (which costs like two or three stamps). Or if someone has an extra countersink of the correct size to sell me that would be great too. What degree countersink should I use? 90 or 100 or 120?

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Is this to countersink the bridge pin holes? You can get a carbide burr at a machine shop for much less money.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I am not sure which carbide burr you're referring to... I tried to find a suitable burr but they were either too steep or too expensive. I thought about using a angle router bit but I think that might chatter a lot. Enco sells most countersink at 5 bucks a piece...

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

A router bit to chamfer your bridge pin holes seems like a bad idea…
Any machine shop should carry a selection of carbide burrs suitable for the job. Otherwise a hardware store/home centre should have countersinks.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

The countersink from Lee Valley is awesome ...its about 15 bucks IIRC.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Hi Tai Fu,

Here is the link to the Lee valley ones:

http://www.leevalley.com/wood/Search.aspx?c=2&action=n

I just bought the larger one on the top row right but have other ones as well that I bought at local industrial stores (for metal working). They are 82 degrees and should be fairly common, even in Taiwan.

Good luck!

Shane

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Canada

There was a discussion on this awhile back and I believe it was Mario who said he used a rotary tool grinding stone.

Warren.

Hey Warren,

That particular one looks way too pointy (to get technical!). Also those units are quite soft and the abrasive breaks off quite easily so that would concern me as the strings may rest against that area a bit. But hey, Mario has WAY more experience at that than me...but still there must be other angles that he was referring too.

Shane

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Canada

Here is a link to MSC Industrial that will show you what a carbide burr looks like.

http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=1666594&PMT4NO=61622651

I use one to make the countersunk holes on the bridge to accommodate the round heads of the bridge pins. If you want one, I can get them in a day or two from the MSC warehouse in Nevada. Then mail it over to you.

Best used in a drill press for overall stability, but can go in a variable speed hand drill if you're careful.

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Hank Mauel

I think this is what I need:

http://www1.mscdirect.com/CGI/NNSRIT?PM ... O=61623286

I hope the 90 degree angle is correct.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

I most likely have the wrong bit pictured.

Here's Mario's original post.



Maybe it was this one...

I have a couple of really good countersinks, but prefer to use a carbide (or high speed steel)
burr. I find the countesinks tend to cause chipping where the cutting edge meets end grain. Sometimes a dull old burr will do a smoother job than an sharp, aggressive one.

Yup, I quite like the look of the burr that Hank linked to. I printed that page off and I will be attending my local Industrial Supply and asking them to get me one and will give that a try. I like that it creates a round hole rather than a chamfered one.

Hey Warren, no worries I was just noting that the angle needed to be shallower. That one looks more like the angle I would like to see.

Shane

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Canada

I used to use a Dremel-style stone to do this, but they clog up pretty quickly and burn rather than cut, which I find undesirable.
I use a carbide burr mounted in a hand-powered drill, it will probably last my entire career and some, is very clean and manageable and I even use it to slightly countersink tuner/end pin holes before finishing.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

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Todd Rose
Ithaca, NY

https://www.dreamingrosesecobnb.com/todds-art-music

https://www.facebook.com/ToddRoseGuitars/

Lee Valley. I've used them for years and would never go back to any other for wood.

Danny