Just a thought
Saw a mod the other day that had the sound holes in the back with a false back and no holes in the top. Could you possibly cut sound holes in the back and do the repairs through them and then add a false back. That may even increase the volume

When this is all done, I'd like to play that dulcimer with someone.  It's soooooo beautiful.  A rosette on the bottom like the design on the top would work very well and might even play a little louder. I do a lot of scroll work on my instruments....but the little darling hearts on the top are really tiny...I could do them, but maybe not as perfectly as those are done.  Ask Bob where he gets his lazer rosettes and maybe have one made the same as the top.  Keep us "in tune" (pun intended) to what you decide to do with that lovely dulcimer.  aloha, irene

Just a quick reply- If you finally come to the conclusion - after long research and consideration- that you must physically alter the instrument to access the repairs, I thing Irene's idea is excellent!!  Cut a very nice hole in the bottom of the dulcimer to access repair work and use your creativity in plugin the hole with something faithful to the design of the instrument (i.,e., a pretty rosette with hearts).

Many minds at work can achieve anything.

I see two issues with your repair.  The first is getting the glue to where you want it, the second is holding down the loose brace while the glue sets. 

Steady your nerves.

For the glue,  find a dentists mirror (Dollar Store, Harbor Freight, eBay) that will fit in a soundhole near the brace you want to glue.  Shine a small flashlight into the soundhole on the other side of the instrument.  This should allow you to see the loose brace.  Shape two curved pieces of wood that are long enough to reach the loose brace.  Use one to prop the brace away from the back far enough to insert glue.  Take the other and put a small enough drop of glue so that it stays on when you reach into the instrument to place the glue under the bridge.  Repeat until you believe enough glue is under the brace to hold it.  Pull out both pieces of wood.

Halfway home.

Fully insert the strongest of the shaped pieces of wood and flip it with a tweezer so that it  curves up with one end resting on top of the brace.  Take a dowel that fits through the sound hole and rest it on the wood piece.  Take a clamp and gently clamp down on the dowel until the brace is in place.

Walk away and let it sit for a couple days.

For better instructions, look up gluing a loose brace on stewmac.com.  They will show you how to do it on a guitar, which is easier because it has a larger body and a bigger soundhole.

Be patient, don't give up.

Thanks Bob and Irene.  I don't have a clue what the collector value of this Carstanjen would be.  It was sold at eBay auction and considering the current market, I probably paid too much for it.  But, I'd been looking for a courting dulcimer and this was about the coolest I've seen.  It's obvious issues (and the intonation problems were not obvious of course) scared off other bidders so I got it as the sole bidder at the opening price.  I've done what I could to coax life out of it and to this point all set up efforts have been reversible.  It has really nice voices on both sides.  I tuned one side DAdd, the other GEgg (i.e. baritone) with the thought that the baritone side E could optionally be dropped to a D for a "new ionian" D tuning.  As previously stated, the rattle can be pretty much avoided if picking or plucking is confined to the strum hollow.  So I'm not in a big hurry to get the job done and am quite willing to wait for some sound advice before dealing with my "resonater dulcimer" further - beyond playing it of course.

I've followed some some threads on John Maxwell dulcimers and its ironic how much I can empathize with the push and pull between obvious craftsmanship coupled with an intonation nightmare - especially now that I recently obtained a Maxwell myself.

I finally met a local player/builder/repairman that I will be meeting and I'm sure we'll put this Carstanjen through its paces as a duo.  This guy has built courting dulcimers and says the difference in single versus two players playing is incredible.

Matt Berg, has got me pondering if maybe a fix could be accomplished through the existing sound holes after all.  I've got some ideas but will hold them for now.  I hope he jumps in here again as I'm wondering what he had in mind.

I loved reading all the write up of this man. wow.  It would be a shame to cut all those darling hearts out to make a round hole to fix the braces, but those braces can BUZZZZZ.  bummers. I'd suggest maybe a possible nice made heart UNDERSIDE of this beautiful instrument.  THEN fix the braces.  Best of all I'd follow Bob's suggestions.  aloha, irene

What an amazing and even historic instrument! And that seems like a big issue to fix. Just curious, Jim, have you talked to a professional instrument restorer?  A quick Google search discovered the Smithsonian Museum Conservation Institute  https://www.si.edu/mci/english/learn_more/taking_care/musinst.html

They can give you leads to conservators in various locations in the US and Canada. Not sure if it's financially feasible but they may have some good ideas for you.

Best wishes for your project.

~Bob

 

Thanks for the reply Matt.  "Thump testing" was telling me the braces are about three-quarters the way between the fourth and fifth fret on both necks (i.e. symmetrical, as one would expect).  I inserted a curved piece of insulated solid core wire through the large sound holes to feel along the underside of the top and found the braces just 1 3/4" from the center of the heart going toward the middle of the dulcimer body.  I did the same through the central "rosette" and got 3 3/4" for both braces.  This agrees with the "thump testing".

The two large hearts in the bouts are 25mm wide x 15mm "valley to valley" (1" x 9/16').  The small hearts both in the bouts and the central circle are 19mm x 11 mm (3/4" x 7/16").  The central rosette is 16mm in the widest dimension and is 12mm in the shortest (11/16" x 1/2").

Taking a stab at reading your mind, yes I can get an endoscope in there and I am thinking of getting one for this and other projects.  I was somewhat optimistic that the bout holes are such short distance away from potential access points.  But those sound holes would seem too limiting for the work that needs to be done - I think.  If you know better, clue me in - I'd rather leave the sound board intact.

The contemplated option of a circle cut around the central heart pattern would give me a 3 1/4" diameter access hole to work with.  Hell, I could get my hand through that to apply glue and install temporary force-fit struts between glued braces and the bottom.  I'd fashion a jig to temporally affix to the central sound holes that would in turn provide a pivot post for an arm fitted with a razor knife blade to do the cutting - so the cut would be less than 1/16 wide. I'd probably have to widen that cut a bit for the decorative binding circle that would dress up the sound hole disk when it was reinstalled. To spice things up I'm even contemplating installing an ivory colored O-Port in the large hole then press fitting the sound-hole disk into that. This should provide some awesome resonance.  The down-side is that this access hole cutting scheme involves non-reversible modifications that may have a detrimental affect on the instrument's collector value (if any).

I would entertain back removal, but as previously stated, this task appears daunting considering the dulcimer's size, shape and under-scroll shelves.  Here's a more complete set of "as found" photos that better describe what I'm up against. The file also includes some information regarding the builder.

Sorry for the long-winded post, but then again, I'm asking for information that goes well beyond a yes/no answer.

Jim,

Could you be more specific on the location of the loose bracing?  Also approximation dimensions of the heart sound holes.

A while back I purchased a Mikael Carstanjen Courting Dulcimer.  It's what you'd call a "project dulcimer".  It had some intonation issues that I have successfully addressed.  But there is apparently some loose bracing and I'm somewhat at odds as to how to proceed.  The attached photo file should explain the past, present, and proposed future better than I can here.  I'm hoping for some feedback on what my best options are.   Thanks in advance!

updated by @jim-hedman: 04/20/18 04:53:47AM