Digital BW, The Print

Don,

>>...I coated my first Eclipse 16x20 (17x22 paper)
>>with a wire-wound rod and polyurethane.
>>The process appears to scale-up to this level without
>> too much trouble.
>

>Why do you use a wire wrapped rod? Have you considered
>using a glass tube? These are commonly used to
>coat alternative process emulsions onto paper.

I've never done any coating with a glass tube.  So, I simply don't know
anything about them.  Is there a good description & picture of them on the
web somewhere?

>How do you clean your rod

The polyurethane ("PUR") I'm using is water-borne.  So, I just rinse the rod
under the faucet in my darkroom sink, which is where I do the coating.  For
the long 16x20 rod I first just put it into the bottom of the sink that I'd
filled to several inches with water. (I have one of those photo-washer type
stoppers that allows the sink to fill to a few inches before water can
drain.)  So, the rod sat in water for a while before I rinsed it more
thoroughly.

>... how do you introduce the urethane onto the rod?

I use a syringe to pull the PUR from the can and lay down a "bead" above the
print.  The rod is then just pulled through the bead and across the paper.

>> The main problem I had in setting up is that I have
>>no totally-flat counter top.

>... use a heavy piece of glass plate for coating.

Yes, I've ordered one.  The local glass shop can only go to 1/4 inch, so
I'll try that first.  If there are different types/qualities of glass that
could be flatter than others, the locals don't know about it.  (There are
limitations to living in a small town.)

I also will replace my crude plywood counter top cover with a
melamine-coated particle board.  (I lay a piece of solid plywood over my
darkroom wet sink.)

Also, with 8x10s I found that a couple pieces of paper under the print
seemed to help.  I had not done this with the 16x20.  I'll probably get a
roll of butcher paper for this and to help with clean-up (especially when I
try some solvent-based coatings).

>> ... the coating shows some signs of unevenness --

>Using a glass rod will eliminate this, an even
>bead of coating can be
>gotten by slightly lifting the rod before pushing forward.

With 8x10s I get totally even coating.  So, I'm hopeful that the wire-wound
rod can do it.  I would like to see how these glass tubes/rods work,
however.

Paul
http://www.PaulRoark.com