[alt-photo] Re: PVA for SIZE & GUM ??+MSDS mystery broken

[pfriedrichsen at sympatico.ca]

Joseph's link to the MSDS is a great help. The MSDS provides valuable 
insight. From that, it is stated as being an Ethylene/Vinyl Acetate 
Copolymer. This is a different animal than many of the acid free PVAs 
we may find at the art store which are usually just PolyVinyl 
acetate. They lack water resistance and that is good for book binding 
so the work can be reversed with water/steam if need be.The Ethylene 
makes it much more water resistant, improves adhesion, and increases 
flexibility. This all makes sense to me. I tried a white wood glue 
once (Elmers brand) and it did a very bad job, as water was slowly 
absorbed by it and the paper went limp.

What we have in the Gamblin size is what is called VAE or Vinyl 
Acetate Ethylene Copolymer. The higher flexibility allows it to flex 
with fabric and water resistance is much better.

Bottom line is: you may get lucky to find a similar performing off 
the shelf "white glue" as size but it seems like a real crap shoot. 
Most will fail the water resistance requirement.

A good summary can be found on page  4 (second last paragraph on the 
right column) of the book:


Solvent-free adhesives

 By T.E. Rolando

Google books link is:
http://books.google.ca/books?id=f7B7rsF3jOYC&printsec=frontcover&source=gbs_v2_summary_r&cad=0#v=onepage&q=&f=false
scroll down to page 4

Hope this helps

Peter Friedrichsen

At 08:32 AM 03/06/2010, you wrote:
>The link to Gamblin's MSDS for their PVA size can be found on this page:
>
>http://www.gamblincolors.com/sizes.grounds/index.html
>
>Joe
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