I've been using the Richeson 9010 brush for a while now (having been introduced to it through a great workshop with the wonderful Kerik Kouklis) and have some questions on technique that I hope more experienced folks can help with. I'm doing Pt/Pd printing on COT 320 and use a 2 inch brush.
I've read many posts in the past from others about using it wet, shaking it 'til the excess is gone (but no separation in the bristles) and going left to right and up and down, etc. On an 8x10 COT 320, I'm using 18 drops FO + 14 Pd + 4 Pd for each of 2 separate coats--the 1st is diluted with water (so total volume is still 36 drops per coat). My problem is knowing when to stop brushing--It seems to take a long time before the amount of liquid I'm pushing around decreases to where I can absorb the leftover with the edge of a paper towel (I've brushed as long as 12+ min. or so sometimes). This often leads to fine white lines on the final print, which I believe is from abrasion. My darkroom is at 55%RH via a humidifier and I pre-humidify each sheet before coating for about a minute or so a few inches from the humidifier's nozzle.
Is this normal behavior for the brush or am I doing something wrong? Can someone give me a rough idea of how long I should be pushing the sensitizer around before I call it quits and soak up the rest with a paper towel? Or should I be using less sensitizer? Thanks for you help!