what glue did Eastman used to attach mando tops ?

[mandolagirl]

Good morning mandolin lovers. Here's a little repair query from New Zealand. I have been hanging around on the Cafe for years, rarely offering any ideas - because someone else has usually done it already, or better. But I have spent half a lifetime making and repairing instruments.
On my bench at the moment is an Eastman 814 mandolin which I think has suffered from a long hot journey in a shipping container. Happily, after acclimatising to our local climate, there are no wood cracks and only a tiny bulge in one side. Neck angle doesn't quite match the top but that's easily adjusted with a thin shim under the fingerboard.
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More seriously, the top has come off the end block and the sides, just as far round as the widest part of the front. After opening the binding, this part of the joint separated very easily with a thin pallette knife, but the rest of the top joint seems completely solid. Checking upper parts of the joint through the soundhole confirms this. I would like to reglue just the part which has opened, rather than remove and replace the whole top.
So it would be helpful to know what kind of glue was originally in the joint. A You Tube clip shows Eastman tops being attached with hide glue, but the residue I can see on this end block doesn't look like hide glue, and of course they may have used different glues at different times.
Also the fingerboard on this particular instrument was attached with some kind of cross-linked PVA glue, which only finally gave up with much heat, a hot knife, and hot water and meths. Even then, it didn't begin to dissolve, but was soft enough to be separated and scraped off neck and fingerboard.

So... does anyone know what kind of glue may be on the separated top/side joint in this Eastman 814 ?
Kia Ora from New Zealand. Simcha.

[sunburst]

I would have assumed hide glue because of the violin family roots of the Eastman company, but I don't know what they used. I think I would try some De-Glue Goo on the residue that you can see. I don't know if you can easily get De-Glue Goo where you are, and if not vinegar (acetic acid) will dissolve the glue if it is hide glue, PVA of other water based glue. The dissolved glue will closely resemble the uncured version of itself, and perhaps then you can tell what it is.
There's always the option of cleaning away all the old glue also. Then it doesn't really matter what it was.

[Tavy]

You could also try adding some warm water to the exposed glue and see if you can re-activate it (make it sticky again as per HHG or Fish glue), if yes you're in luck, if no, you're going to have to clean it out.

[mandolagirl]

Sunburst, Tavy, thankyou for the advice. I will try hot water, and strong vinegar separately on parts of the open top/side joint - see if anything dissolves. I would have expected hide glue because of eastman's history with violins , but the high tech polymer glue under the fingerboard was unexpected. Every fiddle fingerboard I have ever replaced was attached with hide glue. I wonder why they used something different for mandolin fingerboard.

[mandiogenes]

I found the following verbiage about Eastman mando construction/materials on the Gianna website:

Eastman mandolins are completely handmade using traditional techniques employed in violin making.

Air-dried tonewoods
Acoustically transparent hide glue
Varnish or varnish/nitro finish
Bone nut
High quality Schaller or Gotoh tuners
Lightly radiused fingerboard
...