Bridge Location

Questions and answers for beginners. If you have a question, so do most other people.
scamp
Posts: 223
Joined: Sat Mar 26, 2022 8:19 pm

Bridge Location

Post by scamp »

Just about ready to start finishing the Guitar.

Last major step is to locate the bridge and mask off the location for finishing.
According to Bill Cory"s book, you measure the distance from the nut-end of the fret board to the crown of the 12th fret. The center of the bridge saddle between the D and E strings should be this same distance away from the 12th fret plus a compensation of 7/64 ( 0.11 inch ).
Is this generally accepted as correct?
Any feedback on this appreciated as I don't want to muck this up.

Also, Bill Cory secures the bridge position by drilling two 1/16 inch holes ( or possibly two 3/64 inch holes) through the bridge saddle slot into the bridge plate and then secures it with appropriate brads (wire nails) so it doesn't move. He then drills all the bridge pin holes using a 5/32 drill bit.

He then masks the area under the bridge, 1/16 inch smaller than the edge of the bridge.

So.... Is this what you would recommend?
If not, what?

Not sure it makes sense to drill all the bridge pin holes at this point or even drill holes to secure the bridge, given your only masking off the bridge location.

Scamp
bftobin
Posts: 64
Joined: Sun Aug 24, 2014 12:27 pm

Re: Bridge Location

Post by bftobin »

There's several variations of this process. The main issue for me is keeping the bridge from moving when clamping it.
Some people finish the top and then scrape away the finish where the bridge goes and others mask off the bridge area and then finish.Using a product called Frisket to mask off the area works well and it's available in different thicknesses. If you're going to cut the mask smaller, you may want to rout a small area around the bottom edge of your bridge, so it will sit in a 'pocket' left by the mask. Personally, I like to drill two spots in the saddle to make absolutely sure the bridge does not move when clamping. All the bridge-pin holes are drilled after. And as always, measure twice, then glue up.

Brent
tippie53
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Joined: Fri Mar 03, 2006 7:09 pm
Location: Hegins, Pa
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Re: Bridge Location

Post by tippie53 »

https://www.youtube.com/watch?v=EJG5Frbu78c
my favorite trick is a 10/32 machine screw in the 2 E holes don't drill through just into the top
that keeps it from moving and from glue dripping into the guitar
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
scamp
Posts: 223
Joined: Sat Mar 26, 2022 8:19 pm

Re: Bridge Location

Post by scamp »

I think I'm going to try and mask off the area under the bridge so I don't need to grind off the finish.
What is the best tape to use to do this.
I was thinking of just blue painters masking tape.
Someone suggested something called "Frisket"
Any opinions on what would work best and why?

Thanks
Kevin Sjostrand
Posts: 3712
Joined: Sat Feb 09, 2008 8:06 pm
Location: Visalia, CA

Re: Bridge Location

Post by Kevin Sjostrand »

I have always used the blue painters tape and it works great. Another benefit when you put your finish on the top
put it over the tape also, then when you pull the tape you can mic the thickness of the tape with out finish, and with finish and you'll have a very close indication of how much finish you have on your top. Works very well when spraying, but if you are wiping on, is it Tru Oil you are thinking of using?, it should work out as well.

Also when you pull the tape, give the top surface where then tape was a rub with some Naptha, (clean the tape glue residue) then scuff it up a little with some 220 grit paper. You should have a nice gluing surface.
Diane Kauffmds
Posts: 3246
Joined: Sun Mar 09, 2014 8:13 pm

Re: Bridge Location

Post by Diane Kauffmds »

I like using 3M 233+ green tape for everything. But, if you have blue painters tape or masking tape, they'll work too.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
scamp
Posts: 223
Joined: Sat Mar 26, 2022 8:19 pm

Re: Bridge Location

Post by scamp »

Your suggestions are, as usual, were very helpful.
Thanks.

BTW...Did some research into how to locate the bridge and discovered some interesting and surprising information.

Don Cory's book tells you to set the bridge at the center of the saddle between the G and D strings at 2X the 12th fret distance from the nut plus a fudge factor of 0.10 inch.
He also tells you to make the bridge perpendicular to the center line.

John H's youtube video tells you to focus on the high and low E string length and for a 25.4 scale, make the high string 25.5 and the low string 25 5/8 ( 25.625).

I checked my bridge and expected the saddle slot ( which is not parallel to the edge to the bridge ) to be sloped relative to the edge of the bridge so there would be a 1/8 inch difference between the high and low E strings . To my surprise, it's more like 0.10 inch.

So... this would mean that setting up the bridge using 25.5 for the high and 25 5/8 for the low E strings would result in a bridge that was not perpendicular to the center line. I have a Martin D28 so I took a look at the bridge and sure enough it isn't perpendicular to the center line of the guitar. It is slightly sloped to make the low E string length a bit longer.

Also, found out the my OM isn't exactly a 25.4 scale when I measured the 12th fret. More like 25.375. So I needed to adjust the High and Low string length. Found a neat software tool on the Stewmac web site that calculates the high and low E string length for a given scale so I can modify it for my guitar.

So I think I'm ready to set up my bridge. As usual, noting is as simple as it seems.

Scamp
tippie53
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Location: Hegins, Pa
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Re: Bridge Location

Post by tippie53 »

be wary of mixing stew macs rules to other kits you may not get a good result.
you have to understand that setting up the bridge is critical to the method of the player
a blue grasser and lead play usually have a heavier picking style and you will have to set the saddle back a touch more to allow for the string bending

a finger style a little less
so if you can set the length as I described inside the saddle slot you are golden. you definitely do not want to be short and be sharp
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
tippie53
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Joined: Fri Mar 03, 2006 7:09 pm
Location: Hegins, Pa
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Re: Bridge Location

Post by tippie53 »

if you set up the way I told you in the video you will find your intonation will be more on than not. There is not perfect intonated fretting instrument .

I use a 3 degree angle for compensation , and then I can do some tweaking later and I don't have issues with this. I have been doing it for 22 years.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
scamp
Posts: 223
Joined: Sat Mar 26, 2022 8:19 pm

Re: Bridge Location

Post by scamp »

tippie53 wrote: Wed Jun 01, 2022 3:55 pm if you set up the way I told you in the video you will find your intonation will be more on than not. There is not perfect intonated fretting instrument .

I use a 3 degree angle for compensation , and then I can do some tweaking later and I don't have issues with this. I have been doing it for 22 years.
So should I just set it up with 25.5 for the high E and 25 5/8 for the low E, even if the scale is a bit short?
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