Thanks for the compliment, Howard :-) It is theoretically possible to apply not enough hot glue although I can hardly imagine how. It is however possible to do it incorrectly.
I am not too much of a competent luthier, although - after quite some woodworking experience - I have been trying to learn as much as I could from David van Edwards in three summer schools. Also I have a friend who is a professional luthier and we have been discussing this issue in great lengths. It is still my belief that there is almost no glue between jointed parts. Practically zero gap. I do not know if you are familiar with the hot glue business, absolutely no insult intended here. One applies quite a lot of the stuff, one major purpose being to warm up the wood. For example for the soundboard joint, one rubs both parts against another until one feels that the joint begins to stick, at least that is what we do here. By this moment, all pores are filled with glue and this is what holds the parts together. There is almost no glue in the joint itself, it is all in the pores. If one just applies some glue to the cold surfaces like one does with PVA glue and clamps everything together, there will be a weak joint. This may well be called glue-starved. One wants enough glue in the pores, but not in the joint. For a good hide glue joint, the amount of clamping pressure is almost completely irrelevant. There is no such thing as too little or too much pressure. It is all surface preparation and glueing technique that counts. I am fairly confident that your luthier would not think much differently. Gernot On 25.07.2010, at 20:01, howard posner wrote: On Jul 25, 2010, at 10:57 AM, Gernot Hilger wrote: With hide glue, this is not possible. For example, when jointing a soundboard, one would rub both parts together to squeeze out any surplus glue. Even under the microscope, there will be no visible joint thickness. Have a look at your lute's front. The very capable builder who repaired the damage to my glue-starved instrument thought differently. -- Neu: GMX De-Mail - Einfach wie E-Mail, sicher wie ein Brief! Jetzt De-Mail-Adresse reservieren: http://portal.gmx.net/de/go/demail To get on or off this list see list information at http://www.cs.dartmouth.edu/~wbc/lute-admin/index.html
