varnish

[eagleI]

Is it common for varnishes to get a milky look in fountain when running? I am thinking this is air in the varnish....or water feedback. Also is it true that measuring the amount going down can be based on the 4 color ink not being drawn back into rollers from blanket...I always try to just find that window. As so that im not applying alot of varnish down. Just curious how outher people run varnishes?

 

[turbotom1052]

if your seeing the varnish in your ink fountain turning milky white, (especially on the ends) its usually as a result of running too much water. The way i determine how much varnish to lay down is to take a visual peek at the last form roller (usually right above the plate) I look for an even "nap"
across the lenghth of that roller just after inching the press around a bit. The visual cue your looking for can be arrived at with either experience or by comparing it to the ink film measure with an ink film thickness guage. AKA peto guage. If your varnishing inline a pretty good indicator of too little varnish would be your varnish rollers becoming contaminated by the inks laid down before it. Unfortunatley too much varnish will be indicated by offsetting or blocking of the load in the delivery.