Do you cut your saddle slots before or after gluing the bridge ?

[murrmac123]

Apropos of a thread on the Build and Repair Forum, I thought it might be of interest to find out the preferences of the pros on whether they cut the saddle slots prior to gluing the bridge, or whether they machine them subsequently.

Similarly, do you drill the bridgepin holes before or after fitting the bridge ?

[phavriluk]

I want to understand why it is a better idea to cut the saddle slot in the bridge after the bridge has been attached, so that I'll be working on an uneven surface with final finish applied, as opposed to working on the bridge itself clamped nice and safe to a work surface where a router can be used with some precision and preparation. And early in the bridgemaking task, if I wished to cut the saddle slot first in the bridge blank.

It seems as if this advice is appropriate only when making a bridge from a blank. I can't recall seeing bridges offered for sale finished but for a saddle slot.

Is there a subset of this technique involving positively but temporarily locating the bridge, removing it from the guitar, making the saddle slot on the bench, and then installing the bridge?

Thanks very much.

[Hot Vibrato]

Originally Posted by phavriluk

I want to understand why it is a better idea to cut the saddle slot in the bridge after the bridge has been attached, so that I'll be working on an uneven surface with final finish applied, as opposed to working on the bridge itself clamped nice and safe to a work surface where a router can be used with some precision and preparation. And early in the bridgemaking task, if I wished to cut the saddle slot first in the bridge blank.

It seems as if this advice is appropriate only when making a bridge from a blank. I can't recall seeing bridges offered for sale finished but for a saddle slot.

I cut the saddle slot after gluing the bridge. That way, i can string it up and install some temporary saddles before committing to routing the saddle slot. That way I know for a fact that the intonation is as perfect as possible for the proposed string gauge and action.

I drill the pin holes before installation, but I don't drill the outside E string holes all the way through. That way I can use small pins for holding the bridge in place while gluing. This requires doweling the outside bridge pin holes in the top, but it's worth the extra effort, because smaller pins hold the bridge precisely where I want it. I would never rely on pins or bolts through the existing bridge pin holes for alignment purposes - way too sloppy.

I'm not sure if pre-made bridges are available without a saddle slot. Any time I need to replace a bridge, I just make one.

[Howard Klepper]

Originally Posted by murrmac123

Apropos of a thread on the Build and Repair Forum, I thought it might be of interest to find out the preferences of the pros on whether they cut the saddle slots prior to gluing the bridge, or whether they machine them subsequently.

Similarly, do you drill the bridgepin holes before or after fitting the bridge ?

slot after

what do you mean by "fitting?" They are drilled before I glue.

[murrmac123]

Originally Posted by Howard Klepper

slot after

what do you mean by "fitting?" They are drilled before I glue.

I stand corrected. I should have said "gluing" ..which I did say in the poll.

[theEdwinson]

I have always slotted my bridges after they are glued on, as one of the final steps in the assembly and set-up of a new guitar. I use my shop-built version of the StewMac Saddle Slotting Jig, with a DeWalt 1 1/3 hp router, and various flat-bottom, down-shearing end mills.
Why?
Because I have the extra assurance of exact placement of the bridge saddle after the guitar is assembled, with the neck permanently installed. I can check and double check saddle placement with my scale templates and machinist rules, with no guesswork. I want the guitar to be at its final stasis before I place the saddle. An error of 1/32" placement is huge, and this is how you avoid making that error.

Also, I build all my guitars with a 25' or 30' top radius; and routing the saddle slot after the bridge is glued on assures me of a perfectly flat-bottom slot. Of course, I always sand in the footprint of the bridge to conform to the top's radius; but if I routed the saddle slot BEFORE gluing it on, there might be some very minor warp imposed on the bottom of the saddle slot.
As we all know, it is absolutely essential to have 100% contact between the saddle and the bottom of the saddle slot, for best vibrational transmission to the guitar top, and to avoid phantom buzzes and other anomalous noises you might get from a poorly fitted saddle.

[Halcyon/Tinker]

Before, personally.

I built a jig that locates the bridge pins holes using the saddle slot as it's registration point. Route slot, insert jig, drill holes (only part way through). The saddle slot and bridge pin holes are always in the exact same relationship with each other.

Then I use a jig that locates the saddle slot in correct relationship to the fingerboard. With the saddle slot in the right place, the pin holes are as well.

Then I drill the outer strings all the way through with the bridge located correctly and doublesticked to the top, and use drill bits blunt end down as holding pins when I do the glue up.

In the end, I don't think it matters much which order the operations occur in, as long as the slot and pins end up in the right place. Just a matter of picking your comfort/risk level...

[dekutree64]

I drill the holes and route the saddle slot first thing while the bridge blank is still rectangular. Then plane from the bottom to taper the thickness, which tilts the holes and slot backward a few degrees. Scrape the bottom concave, cut out the shape, carve the upper side, sand to fit on the guitar (shouldn't take much, thanks to the prior scraping), and glue it on. Then drill the holes through the soundboard, ream, countersink, and slot them.

[Rodger Knox]

I route the saddle slot first, then carve the bridge, and then drill the bridgepin holes. Bridge is complete before it is glued to the top.
I don't have any jigs or fixtures that would allow me to cut the slot with a 6° to 10° back angle after the bridge is attached, and I have a hard time believing that I would be able to route the slot more accurately with the bridge attached to the guitar than how accurately I can locate the bridge.
Those that come from different backgrounds will feel differently, and probably are able to more accurately route the slot after the bridge is attached, but not me.

[redir]

I do everything necessary including finishing (where applicable) to the bridge before gluing it down. It seems to great a risk to me to trust myself and my jigs to rout out a saddle after it's already on the top.

[phavriluk]

Redir, Rodger: That's what I was fumbling around trying to inquire about. Nice to see succinct and clear comments. Thanks..

[Martin Keith]

I generally slot beforehand. It just feels safer, in line with what other folks have already said. I use the outermost pin holes to index the bridge to the top using 10-24 machine screws. These can also be used with tee-nuts or nuts/washers inside to provide most of the clamping force for the actual gluing. We did hundreds of guitars like this at Veillette and never had any issues with bad placement. Once you nail down your location for a given string/scale/tuning combination, you can just reproduce it.

However, I've been reconsidering this week, since I just (finally!) built a jig for slotting a pin bridge in place (i.e. glued on), for a repair job I had on the bench.
The advantage of being able to pin down exact intonation points is attractive, especially if it's a new model/scale/custom string gauge etc. where the predetermined points are not necessarily right on.

I did once make a set of hollow bolts that let you string up the guitar without gluing the bridge - you bolt on the bridge first, then run strings through the bolts and test it that way. (I think Stew Mac sells a version of this).
That actually worked out pretty well. Maybe this is the "middle way"?
It's not hard to bore out a set of brass 10-24 machine screws with a .080" hole up the middle, especially if you have access to a machine lathe.
Then, bolt on the bridge and string up to test. If the bolts are tight, it shouldn't move at all from the gluing position.

Cheers,
Martin

[murrmac123]

Originally Posted by Martin Keith

However, I've been reconsidering this week, since I just (finally!) built a jig for slotting a pin bridge in place (i.e. glued on), for a repair job I had on the bench.
The advantage of being able to pin down exact intonation points is attractive, especially if it's a new model/scale/custom string gauge etc. where the predetermined points are not necessarily right on.

I did once make a set of hollow bolts that let you string up the guitar without gluing the bridge - you bolt on the bridge first, then run strings through the bolts and test it that way. (I think Stew Mac sells a version of this).

I have just this past weekend ordered the Stewmac jig and the "intonator" which Dan Erlewine demonstrates in this video

[yoni]

Originally Posted by murrmac123

I have just this past weekend ordered the Stewmac jig and the "intonator" which Dan Erlewine demonstrates in this video

**** video...I want to know what happens next!!!

[pops]

I have always routed the saddle slot with the bridge glued on. I think it is more accurate. I can't be sure, but I would think a glued on bridge will lift the top under string tension different (less) than one with just two screws.