Digital BW, The Print

>
>Hydrocote is a polyurethane that is already polymerized!...that's why it is
>called "poly".  There are coatings which you add a cross-linker to but they
>are not available in water-based formula.  The problem with viscosity is a
>universal problem with water-based polyurethanes.  They are not really
>soluble in water so people add cosolvents to them.  If the cosolvent (which
>is more volatile than water) begins to evaporate the polymer starts to drop
>out of solution.  The polymer itself is much more viscous than the solution.
>Personally, I don't fine polyurethanes to be a good solution for print
>coating...there are just too many variables that can go wrong.  Acrylics are
>a much better solution and they are commonly used for artists
>materials...polyurethanes...are not.
>
>Robert
>


I have been following this with interest...and even posted several 
times in the past month or two about the virtues of coating with 
acrylic varnish...I agree with Robert that acrylics are a much more 
elegant solution chemically.  Find a good quality artist acrylic 
varnish and intermix the gloss and the matte together until you get 
the degree of gloss you want....Blow it through the same spray 
gun...easy clean up...as long as you don't let the thing dry....I 
shoot a lot of plain water through it after the job and follow it 
with some denatured alcohol to clear our the water...Never had a clog 
problem with the gun...Oh, it doesn't hurt to take an artists brush 
and scrub the tip lightly with some plain water during a long session 
so you don't get build up on the tip.

Bill Agee
-- 

bill agee studio
capistrano beach, ca / laguna beach, ca

http://www.redsilver.com