laminated bridge

[Ron Nossaman]

>
>Titebond is not good at adhesive bonding, where the glue layer is not
>expelled and no molecular links are formed between the two parts glued
>together. That's preceisly why ultra-thin heavily clamped joints are so
>essential for titebond type glues...i.e. extremely high pressures are
>needed...as Hoadley points out considerably more pressure is really
>required than anyone would typically use. Hide glue, as well as being an
>excellent cohesive bonding agent, is also reasonably good adhesively.
>Hence the applications in gluing materials like felt and leather, for
>which yellow glues are useless. Within reasonable limits the adhesive
>strength of hide glue can maintain a poor wood joint where a titebond glue
>would be less adequate....before you come down on this I say reasonable
>limits. Apart from chemical deterioration, the majority of failed old hide 
>glue wood joints can be attributed to wood shrinkage and expansion i.e. 
>movement after the glue has cured, causing the crystalline structure to 
>break.
>
>Stephen


And lo, through the magic of both semantics *and* smoke, hide glue becomes a
better gap filler than Titebond. Truly fantastic. If I get around to it,
Stephen, I'll check the archives to see what you have written about the
known gap filling properties of hide glue in past posts. If I can wade
through it all and find what I think I remember, perhaps we can arrange a
debate between you then, and you now. Meanwhile, if your hide glue was mixed
very thin, there wouldn't be enough solids in the joint to fill much of a
gap once the water evaporated out. If, on the other hand, you mixed your
hide glue to the same consistency as the Titebond, you would have much
better gap filling properties by virtue of having more solid material in the
joint, and clamping requirements similar to those of Titebond. Take your
pick. The properties you described above are more the result of the
viscosity of the different glues than of their adhesive properties. I see
the escape clause here in the form of the phrase 'within reasonable limits'.
Assuming the *same* reasonable limits and conditions for both glues, I don't
think you have a case. 

Yellow glues (I'm presuming Titebond, specifically, to avoid introducing any
more fuzzy generalities into the murky morass), I see, have also
transmogrified (congealed?) into something that is 'useless' for felt and
leather work. This comes as a surprise to me, as it will to any other tech
who happens to accidentally read this. State an opinion, if you like, but
present it as your personal view, not as a fact. Fortunately, the English
language does supply a number of intermittently colorful words, colloquial
and otherwise, to describe this process. Obfuscation, exaggeration,
bombastic prevarication, and misdirection come immediately to mind. Perhaps
if you were more open minded to the possibility that other options exist, or
were aware that a number of other fine glues and adhesives have been
invented since the Stone Age, you wouldn't have to resort to inventing
truths and falsely maligning a fine product to make a point that really
doesn't exist anywhere but in your own mind. Shouldn't hide glue be able to
pull it's own weight without all the showmanship? Just my opinion.

 Ron