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70's D35 bridge and saddle location

Posted: Sun Mar 06, 2016 4:55 pm
by Matt Atkinson
I have a 1970s D35. The neck needed a reset which I am getting ready to glue up. It also has typical 70's Martin issues including a B string, pickguard crack and the saddle (and bridge) is nearly 3\16" too far forward resulting in lousy intonation. There is also a decent belly in the top but I have decided to install a bridge doctor which will easily take care of that. I am not overly concerned about the pickguard crack but I do need to address the bridge/saddle issue. The existing bridge has clearly been shaved down to avoid the neck reset. Nothing much is left of the saddle above the bridge and the bridge pin holes have been aggressively slotted towards the saddle. I have made the neck reset with the existing bridge taken into account. My question is this: Should I fill the saddle slot and re-cut it or install a new bridge? I am afraid that re-cutting the slot will leave things very crowded. I have checked the saddle position and it is precisely the same distance from the 12th fret as the distance to the nut but there is zero compensation. I am not overly concerned with keeping everything original. I think the guitar will sound great once all repairs are made. Looking for suggestions. Thanks,

Re: 70's D35 bridge and saddle location

Posted: Mon Mar 07, 2016 2:47 am
by Michael Lewis
When resetting a neck on a guitar with a shaved bridge the bridge should be replaced with a standard Martin design 5/16" high (the wood part) and the saddle should be 1/8" - 3/16" above the wood when you are done.

I am assuming the neck joins precisely at the 14th fret and has not been cut so it is at less than the 14th fret.

The pick guard issue will continue as the guard shrinks over time, so the remedy is to remove the guard and glue the crack, finish the bare wood left under the guard, and replace the guard with a new self adhesive one. You have to make the finish smooth for the adhesive on the guard to be reliable.

Re: 70's D35 bridge and saddle location

Posted: Mon Mar 07, 2016 3:21 am
by Michael Lewis
I would put the neck on first and then position the bridge. You might need a slightly larger footprint to cover any uncovered wood. I sometimes make a bridge and don't slot it for the saddle until it is glued in place. This way I can check for intonation for each string, mark the path and rout the slot.

Re: 70's D35 bridge and saddle location

Posted: Mon Mar 07, 2016 4:52 am
by Joshua Levin-Epstein
I have a late 70's d-28 with the same bridge placement issue and the saddle was moved back, courtesy of Martin. The intonation is better, but it is crowded, especially at the low e. I've discussed the "Ultimate" repair with a couple of reputable institutions (you'd know them and agree). Part of the plan is contingent upon whether the original footprint is to be maintained. Some people are very sensitive to the slightly enlarged bridge, others aren't. If size matters (sorry) then the plan is to patch the bridge plate and make a bridge with the saddle in the right place and the pin holes moved back a bit. Obviously an involved (and somewhat expensive) job.

I may be out of my league, but if you've adjusted the neck angle for the cut down bridge, it can still be adjusted for one with full height. I think this would be preferable, as it would look right and probably sound better.

That being said, Michael has probably forgotten more about this stuff than I will ever know.

Re: 70's D35 bridge and saddle location

Posted: Mon Mar 07, 2016 7:38 pm
by Matt Atkinson
Thanks all. I will remove and replace the bridge. I am not concerned with having an enlarged bridge. Patching the bridgeplate is something I hadn't considered. Josh, can you give me a basic rundown of the process? Thanks, for all the great advice.

Re: 70's D35 bridge and saddle location

Posted: Tue Mar 08, 2016 5:59 am
by Joshua Levin-Epstein
There are several methods I have seen described. I have not done any of these so I am not speaking with any authority.

1) (with the bridge off) Plug the holes with dowels, fit a maple overlay .090" thick, and re-drill the holes, through the new bridge that has been glued in place. So you would be drilling the holes and slotting the saddle with the bridge in place. (as described by Frank Ford)
2) Plug the bridge plate with the Stew Mac tool. Fill the holes in the top with spruce plugs
3) Dan Erlewine describes making a sandwich of (in this case) rosewood and spruce, plugging both the bridge plate and top at the same time. This sandwich can be expanded to 3 layers, the top being ebony or rosewood to fix damaged holes in the bridge. He also likes to keep the grain of the plugs the same as the material he's patching.

You can tell I read a lot. In my opinion, your guitar (and mine) certainly has enough bridge plate to begin with, so I would try to add as little weight as possible. This would suggest the Stew Mac tool or as small a maple patch (pre war type) as necessary.

This information is worth exactly the purchase price.

Re: 70's D35 bridge and saddle location

Posted: Sun Mar 13, 2016 5:31 pm
by Matt Atkinson
Thanks for all the good advice. I have removed the bridge. The old bridge was set into the finish as expected but it also looks as if the top was compressed by the bridge in some way (?). The step between the raw wood beneath the bridge and the adjacent finished area is almost 1/32" behind the 5th and 6th strings. Less elsewhere.
The top is fairly uneven due to wear and repair and age. I have to move the bridge back 3/16" on the bass end and 3/32" on the treble (it was badly positioned) and will scrape away finish behind it. I am accustomed to shaping a bridge by laying sandpaper on the top and sanding it to fit but this top is irregular and I am looking for suggestions on how to fit it. I'm guessing it's just s slow sand, test and fit process. Advice appreciated, thanks.
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Re: 70's D35 bridge and saddle location

Posted: Sun Mar 13, 2016 6:02 pm
by Matt Atkinson
Looking into this further I have an idea and need you folks to tell me if I'm nuts. Perhaps I could glue a piece of spruce the shape of the old bridge in it's footprint, level it and glue the bridge over that? Crazy?

Re: 70's D35 bridge and saddle location

Posted: Sun Mar 13, 2016 6:22 pm
by Matt Atkinson
IMG_0648.jpg
More issues. Hopeless?

Re: 70's D35 bridge and saddle location

Posted: Mon Mar 14, 2016 9:45 pm
by Matt Atkinson
Humidifying. Fingers crossed.

Re: 70's D35 bridge and saddle location

Posted: Sat Mar 19, 2016 2:59 am
by Michael Lewis
Leave the bottom of the new bridge flat and it will help keep the top flat. If you make it fit the 'contours' of the top they will become a permanent fixture.

Possibly someone has 'cleaned out' the area under the bridge by removing some of the spruce. Tsk tsk! Clean the surface of any glue or finish where the new bridge will cover and glue the bridge with lots of clamping force. I use two spool clamps I made in the outside holes and three regular bridge clamps, one in the center and one on each wing. Use clamping cauls to prevent any marks from the clamps, and reef that sucker down good. My general preference is hot hide glue but good aliphatic resin glue (Titebond, etc.) should suffice. Don't disturb the clamps for 24 hours.