RE: Gum questions - 101

On the subject of coating gum.
I spread gum mixture with a brush and then use a dry foam roller to smooth
the coat.I roll in one direction only applaying little pressure. You have to
time it just so to get a nice coat. It is easy with a bit of practice.
Marek,
Houston TX

>From: Don Bryant <dstevenbryant@mindspring.com>
>Reply-To: alt-photo-process-l@sask.usask.ca
>To: alt-photo-process-l@sask.usask.ca
>Subject: Gum questions - 101
>Date: Thu, 10 Nov 2005 22:17:15 -0500
>
>Since gum seems to be the topic of the evening I have a some questions for
>our gum nation.
>
>1) My brushes seem to have a dichromate stain built up. What is the proper
>way to clean these? I'm guessing a soak in potassium metibisulfite,
>followed
>by a clean water rinse, then perhaps a short bath in an ammonia solution to
>dissolve any residual gum, followed once again by a water rinse then a
>final
>rinse in hair conditioner.
>
>2) I know that sodium dichromate is rarely mentioned for use because of its
>hydroscopic tendency, but compared to potassium dichromate or ammonium
>dichromate would it printer faster or slower have a lower or greater
>contrast than the other two dichromates?
>
>3) Since many gum printers recommend a weak bath of potassium metibisulfite
>(1 to 2%), what is an effective and safe way to wash prints after the
>clearing bath? Should the print then have a treatment in sodium carbonate
>to
>neutralize the acidic pH of the paper? Would the sodium carbonate weaken or
>soften the gum?
>
>4) I've read here and there that some printers use a micro fiber roller to
>coat their paper. In my experience this simply results in a coating with a
>lot of bubbles. Any hints about how to coat with this type of roller?
>
>Thanks,
>
>Don Bryant
>
>
>
>
Received on Fri Nov 11 09:43:45 2005