Gibson Hummingbird needs bridge.

[Michael S. Fields]

A friend brought me this Gibson Hummingbird that was used for testing finishes and wants me to attach a bridge to it. I feel like it may be over my head. I've found lots of info on reattaching bridges, but not about when the top is completely finished. Also, the end of the fingerboard at the sound hole wasn't taped up very well and has quite a bit of finish on it. Any ideas on how to remove it without damaging the binding? One more thing. The little bag in the last picture was fastened to the neck pocket inside the body with Velcro. I have no idea what it's for. Thanks, guys.

Mike Fields

[Mike Kolb]

Yes, the straightedge should just 'kiss' the top of the bridge (minus, of course, any saddle height). So you want your bridge to be .375" thick.  Maybe start with a .425" thickness and that'll give .050" worth of curve-matching to work with, or thicker if you want some insurance, but that increases the ol' sanding workload!  

[Andrew]

Ideally, I think the straightedge should land just in top of the bridge under string tension rather than unstrung, assuming the neck is nice and straight, so its necessary to account for the movement of the top once its under tension. Of course this is tricky when the bridge isnt on yet for a couple of reasons. However, if the straightedge sits .375" over the top where the bridge will be, this leaves about 1/16" of material that could be removed from the top of the bridge after its installed and that movement can be observed and then compensated for. Obviously different guitars exhibit different amounts of movement under tension, but 1/16" *should* be enough room to play with.

[Michael S. Fields]

After much practicing on scrap wood, I finally was able to make a bridge.

Mike Fields

[Michael S. Fields]

I posted this over at the OLF, but I thought I'd see what you guys think, also.

After gluing on the bridge and clamping it over-night, here's what I have. With a straightedge on the frets, it hits the front of the 3/8" tall bridge about 1/16" below the top of the bridge. Before gluing, it would lay just on top of the bridge. The bridge was flat on top, but now has a slight curve and yes, I did sand the bottom of the bridge to match the curve of the guitar top. Also, I don't remember the top having as much curve to it as it does now. But here's what really concerns me: with the neck straight, the fingerboard extension (beyond 14th fret) rises visibly. With a straightedge across all frets, there's a gap at the 12th fret of .006". I put a hygrometer inside the guitar and sealed the sound hole with tape. After a couple of hours, it read 53%. Any ideas, guys? Thanks.

Mike Fields

[Glen H]

You probably need to set the neck back. 1/16 below the top of the bridge will result in a very low saddle height - especially true if the top has more flex in it. Up-ramp of the FB extension also points to a forward set neck.  But, I have learned not to jump to action. You loose nothing by letting it sit a day or two to acclimate/dry, then string it up and check it out.  Good luck.

BTW, nice job protecting the soundhole.

[Michael S. Fields]

FINALLY, I'm finished with this one. I removed the bridge, installed another one using a proper caul, and actually got it playing really good. I told the owner about the neck problem and he said to do the best I could and he'll let the next owner worry about a neck reset. The string height at the 12th fret is 5/64" for the low E and 4/64" for the high E. Also, this is the Pro model and somewhat different than a standard Hummingbird. It's supposed to have a different pickguard, but the owner wanted the one with the birds and flowers, so I had to do a bit of trimming to get it to fit. I really learned a lot and I'm sure I'll do better with the next one. Thanks for all of the help, guys.

Mike Fields

[Glen H]

Nice job!

[charley erck]

Beautifull, looks like a million dollars!

[moonlightluthiers]

For physically locating the bridge (after compensation, etc. is determined)  prepping the top and gluing/positioning the bridge, please see this suggestion: http://www.moonlightluthiers.com/bridgattachment.htm.    The laminated tape technique facilitates finish removal in the area where you want to glue the bridge and locates the bridge with 100% certainty while gluing and clamping.  This also makes glue squeeze out easier to remove.  

[Michael S. Fields]

Thanks, Glen H and Charley Erck. Also, Moonlight Luthiers for the great info page.