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Re: [BKARTS] Food Grade Gelatin?



When, for instance, a calfskin is soaked in water and heated up,
the first adhesive to come off will be gelatin; at higher heats
various grades of hide glue come off until you get down to a dark
brown hide glue which cabinet makers and some bookbinders use.

The current method for evaluating the strength of gelatin/glue
was developed by O.T. Bloom and patented in 1925.

Bloom strength is a measure of the resistance of a glue film
to pressure.

Details are contained in: _The Science and Technology of Gelatin_
A.G. Ward and A. Courts, eds.  Academic Press, London, 1977.

But basically, when I am standing in front of the plastic bulk
bin at the grocery store, I place a small sample of the food
quality gelatin in my mouth and go on about my shopping.

As the gelatin dissolves I am alert for any taste of mold on
my tongue.  If there is any such taste I do not purchase/use
that gelatin.

Here is what happens as glue/gelatin is manufactured.  After
heating to a target temperature the glue-water is taken off
and dried.  If is is not dried quickly enough, mold begins to
form.

If the solution is dried quickly enough, no mold will be visible
on the finished product.

But it can be tasted.

Glycerine can be added to enhance flexibility; it has the additional
benefit of being somewhat sterile, keeping the solution mold free
longer than if no glycerine had been added.

Re: % solution.  I agree with Peter here.  I place some gelatin
in a container and add water.  If it swells up, but leaves some
dry gelatin I spritz some more water on.  Then I heat it up and
use it.  If it is cold in the lab I might use a hot-air gun to
warm up the material before brushing on the glue.

Or, I might stir some wheat starch paste into the glue/gelatin.

It all depends.

Jack


>Hello everyone,
>
>Someone mentioned to me that Food Grade Gelatin is a much better quality
>gelatin than hide glue.  I would love to hear comments and insight that
>anyone might have regarding substituting food grade instead of hide-

(snip)

>Jake Benson

Thompson Conservation Lab.
7549 N. Fenwick
Portland, Oregon  97217
USA

503/735-3942  (ph/fax)

http://home.teleport.com/~tcl

"The lyfe so short; the craft so long to lerne."
Chaucer  _Parlement of Foules_ 1386

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