Official Luthiers Forum!
http://www-.luthiersforum.com/forum/

Gibson Southern Jumbo Bridge
http://www-.luthiersforum.com/forum/viewtopic.php?f=10137&t=52956
Page 1 of 1

Author:  Conor_Searl [ Fri Feb 21, 2020 7:05 pm ]
Post subject:  Gibson Southern Jumbo Bridge

I'm looking for some perspective. I haven't paid too close attention to these details before.

I've got a newer Southern Jumbo here, the bridge is cracked at the saddle slot on the treble side. The slot is cut awfully close to the edge of the bridge, and has a couple holes drilled into the end of the slot to hide the end of a UST. The bridge seems a little thin, but maybe not. With the UST in the slot, there's not much space left for the saddle, it seems like the torque from the saddle is what caused the crack. I'm going to build a new bridge, but was wondering, should I consider making it a little thicker than the original bridge? Would that change the way the instrument responds? I'm pretty sure the customer doesn't want that.

The bridge is .285" thick, (my martin is about .327" I know apples and oranges.)
The saddle slot is .190" deep
The UST .032" thick
The saddle is .382" at its tallest point leaving roughly .224" exposed, seems like a lot...

Author:  Barry Daniels [ Sat Feb 22, 2020 9:40 am ]
Post subject:  Re: Gibson Southern Jumbo Bridge

I hate those reverse belly bridges. There is only a 1/4" of parallel grain there extending beyond the saddle slot. If you pushed the radius further towards the bridge's end to extend the parallel grain you would gain a corresponding amount of strength. Another approach would be to chose a piece of wood where the grain runs back into the bridge so you don't have that weak grain configuration.

Author:  DanKirkland [ Tue Mar 03, 2020 8:54 am ]
Post subject:  Re: Gibson Southern Jumbo Bridge

That crack was probably caused by an improperly fit saddle.

It'd be easier and less of a pain to repair that bridge and make a saddle that actually fits properly. Gibson just tosses in those pre made tusq saddles and they usually don't fit well at all.

Author:  Conor_Searl [ Tue Mar 03, 2020 12:42 pm ]
Post subject:  Re: Gibson Southern Jumbo Bridge

DanKirkland wrote:
That crack was probably caused by an improperly fit saddle.

It'd be easier and less of a pain to repair that bridge and make a saddle that actually fits properly. Gibson just tosses in those pre made tusq saddles and they usually don't fit well at all.


The saddle was my first thought too. I had already replaced the saddle, but thought maybe I had made it too tight. When I got the guitar back though the saddle fit pretty close to perfectly. Didn't have to force it, and it wasn't sloppy at all. I think maybe it was an inherent flaw in the rosewood, a dry environment, and whoever had installed the UST drilled two holes on either side of the saddle, one straight through the bridge and top, and a second at what looks like a 45 degree angle through the bridge and top.

I tried gluing the crack closed first, but when I strung it up the tension popped the crack open again right away. So I've made a new bridge, and glued it up yesterday. Pretty fun actually, and not too much of a headache.

Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/