Bridge replacement and top cracks in Oriole

[Larry Pederson]

I have a new project to work on with the intention of making it a "player" guitar. The early '40s Kalamazoo Oriole that I just bought has lots going for it in that regard. It appears that unfortunately the neck, back, sides and top have been refinished, probably over the original finish, but thankfully the peghead wasn't touched. It had an oversized rectangular replacement rosewood bridge (6" x 1 5/16") glued on but with new bolt holes. The finish was scraped to bare wood to glue this bridge on. The glue has failed "cleanly" and is now off. There is a major crack in line thru the low E peg hole from the sound hole to the binding on the lower bout. Someone skooged some unknown glue (maybe what was used on the bottom of the bridge) into the crack most of the way from the bridge to the lower bout binding where the crack appears to be widest. They used some fine abrasive then to remove any unevenness in the finish along the crack. That took the shine out of the unknown finish.

I think I want to put a new original size rectangular ebony bridge on it. 5" x 1" are the dimensions the best I can tell from original screw holes and some finish outline visible. I don't really care about the visiblity of the scarred finish around the bridge I put on. I want to optimize the sound it produces. Question #1: Should I use the original bridge size or the larger bridge size that it came with?

Another thing I want to add is a bridge plate. This guitar has ladder bracing (nicely intact) but there is NO bridge plate. The ball ends are braced by one of the pine braces that goes the whole width of the top under the bridge. The pine is worn. I was going to make an ebony bridge plate the same dimension as the bridge that will go on. Question #2: How thick should that bridge plate be?

I was going to glue diamond shaped cleats along the underside of the major crack. Question #3: what kind of wood should I use? Question #4: How thick and what size should they be? Question #5: How far apart should they be spaced?

The neck is remarkably straight and frets have virtually no wear and tuners are in good working order with one slightly bent shaft. There are several other more minor cracks in the top that haven't been messed with. I'll fix them as well.

Finally for now, Question #6: What string set would be the heaviest I should use once this guitar is playable? I mostly flatpick fiddle tunes but I know not to expect the volume I get out of my dreadnaughts.

This is my first time on this forum. I'm not attaching a photo of the top because I'm not certain it's appropriate.

I'm looking forward to getting some advice to help me get this distinctive guitar back in action. It apparently spent the first few years of its existence at Guadalcanal during WWII with it's owner who was building the base there and was nicknamed "Fingers." He and the guitar made it back OK.

 

 

[Paul Verticchio]

Hi Larry & WELCOME to the forum (:

I'm only qualified to address you question #6.

As I recall, these guitars don't have adjustable truss rods.

The answer to these types of instruments is: the correct string gauge is the one that allows the neck's geometry to compliment the rest of the setup.  Essentially, the gauge of strings will "set" the relief.  Your strings become your "truss rod". It may be a very light set given the ladder bracing, or could be a heavy set.  The only way to determine this is trial & error.  You'll "know" when the gauge of the set matches the setup.

Hope that helps and best of luck with this VERY cool project,

Paul

[Kerry Krishna]

Larry, welcome to this terrific friendly Forum.  Just so you know, pictures are always appropriate! I would love to see any that you would like to post! 

[Larry Pederson]

[Larry Pederson]

It's a "natural" finish w/solid maple sides and maple "laminate" back. I'm not including photos of those (unless they are requested, of course) since they are solid and the "tortoise" binding is completely intact. You can see the original bridge bolt holes were filled with something, and you can see something of the original bridge outline. Not a pretty sight. 

[Larry Pederson]

Thanks, Paul, for the welcome and your info. There is no obvious truss rod. It may have been manufactured before WWII so it may have a metal neck reinforcement rod. Information from the web says that the less expensive "off brands" Gibson manufactured for don't have adjustable truss rods. I'll start light and work to heavier gauging if necessary I guess. This will be the last step in the project but important nonetheless.

[Eric Steven Johansen]

Larry, I have an Oriole myself that I re-toped several years ago due to a totally compromised original top. A few observations from my experience, number one is that the truss rod is adjustable but the adjuster nut is on the heel end of the rod. Only access is by neck reset. Number two is that with as much as has been done so far in the way of refinish, and since a player is what you're after, you might consider a new top. I X-braced mine and used a nice adirondack top and it's a killer sounding guitar,. 

[Larry Pederson]

Hi Eric, and thanks for your info for sure. I was hoping to find someone who has worked with one of these before. I'm holding out hope for this top since the "belly" is very moderate in lower bout top and braces appear to be securely attached. The cracks appear to be easily reinforced w/properly applied cleats or whatever the right term is. I want to get a good idea of its sound before I do anything drastic. I'm posting a photo of the top now since that was requested above.

Your outcome with the top replacement is very nice to know. Is your Oriole a "natural" finish w/maple sided and maple laminate back too? If I get mine in good playing order and it sounds "ugly" or toneless or unresponsive, I'll keep that replacement in mind as an option.

[Eric Steven Johansen]

Larry, looking at your pics I would agree that the top is worth saving. Mine was way too far gone so replacement was the only option. Mine is also a natural finish with nice figured maple back and sides (solid sides and laminated back). These guitars sound great as originally braced and you'll be surprised by the volume. When I had the neck off I gave the truss rod a twist and the neck is nice and straight now. The only caution I'd give is this neck is glued on every surface so patience is needed to steam it loose. I'd recommend the reset though just to give the rod a "tighten up".

[Larry Pederson]

Not sure if this goes to everyone, but I'm back w/a couple questions!

I'm getting ready to do the neck reset after making some small steps forward ... and at least one step back. I've cleated the cracks, glued in a maple bridge plate since there was only a thin (shallow) pine damaged bridge plate present, made a rectangular ebony bridge the size of the non-original with a compensated saddle slot and glued it on. It moved toward the soundhole since I didn't have correctly sized bolts in a couple peg holes to keep it from sliding a bit. This was my first bridge gluing. I didn't appreciate how wet glue is slippery in this situation. Didn't realize mistake until glue was mostly dry. I decided to leave it for the purpose of stringing it up w/extra light steel strings to get an idea how the guitar sounds. It wasn't playable when I got it. It sounds REALLY good, very responsive and pretty loud, but even w/extra light strings the resulting string action was very high.

In positioning the bridge for gluing, the scale length is 24 3/4" based on measuring from the nut to the middle of fret#12. I TRIED to put the middle of the saddle at the hi E string to that length and it moved. Is that where the scale length is measured to with a compensated saddle slot?

Also I used the saddle slot angle of a Martin D-18 saddle in using a friend's very precise XYZ adjustable router to make the saddle slot in my homemade bridge. The scale length is different for the D-18. Does that make the saddle slot angle incorrect for the Oriole? Since I'm taking the bridge off anyway, I'm willing to make a different bridge if a different saddle slot angle is necessary.

Finally, is it advisable to include bolt holes since both the original bridge apparently was bolted on based on evidence of filled holes just outside the hi and low E bridge pin holes AND another pair of filled holes outside the span of the original holes? I tried to arch the bottom side of the new bridge to mirror the belly in the top and intended to just use yellow glue for this job.

Since I've never done a neck reset, I bought a neck angle gauge w/straight edge from Stewmac and another old but less valuable guitar to practice on. It's a pretty nice early 50's (?) Harmony 00 size w/"steel reinforced neck", ladder bracing and gold treble clef stenciled on the peghead. The tuners are crap and the neck flexes to a very steep angle w/light gauge strings, but other than that it's in fine shape. I paid a lot less for this guitar, and thought it would be a pretty fine fingerpickin' guitar if I succeeded w/the reset.

Thanks for any feedback.

Larry

 

[Joshua Levin-Epstein]

Hi Larry,

Eric & Paul are more qualified than I am (damning them with faint praise) but the entire saddle needs to be farther back than 24 3/4". Stewmac's calculator says to add .03" to both e string lengths. You might want to make a new bridge or fill the slot in the one you've made. After you've reset the neck, cut the slot with the bridge in place. Frank has "articles" on doing this, Stewmac makes a jig for a dremel tool, and people have made their own jigs. I would be tempted to see if you can slip the guitar under that XYZ router.

If it were me, I would affix the bridge without bolts. The bolts were for expedience of manufacture. If you want to use the bridge you've made, fill the holes with inlay so it looks right, but no bolts. Plug the bridge plate and top with appropriate wood before re gluing the bridge.

As an aside, I have a Harmony like the one you've described, right down to the need for a neck reset. It was finished over as well with finish dripping onto the front of the peghead. I was able to remove a lot of that finish with a sharp razor blade because it was on top of another finish. This might work on your Oriole.

Joshua

 

[Eric Steven Johansen]

Damned I am, and in Pauls company, thanks Joshua. My only comment to you Larry is that I'd reset the neck first, and then string her up and check the intonation, before you fill the existing slot. Nothing beats strings for proper set up in my book, and you might get lucky and minor saddle shaping is all she'll need. See the D-35 reset post currently up for a more detailed analysis as to why this might happen. :)

[Larry Pederson]

Thanks to both Joshua and Eric.

I'll proceed w/the Harmony neck reset after I get the angle gauge and information that comes with it. I don't have to do a thing w/the Harmony bridge. It's solidly in place and uncompensated. Will just focus on getting that reset right on the Harmony and it will be rewarded w/new tuners if things go well. 

I'll pay close attention to the D-35 reset post as suggested. The bridge currently on the Oriole will have to come off to use the XYZ router at all. If I get confidence from the Harmony reset, then I will likely tackle the Oriole reset, then deal w/saddle and bridge positions on it.

Thanks again for the information and suggestions!