PDA

View Full Version : Emulsion Not Sticking To Edges Of Glass Plates



Old-N-Feeble
06-03-2012, 08:54 AM
Let me state upfront that I don't shoot wet plate and never intend to... BUT... It seems that most of the wet plates I've seen have the emulsion peeling away from the edges and I've been pondering how to minimize this problem.

My GUESS is that this problem could be vastly reduced by modifying the edges of the glass as follows. I do realize that glass prep and coating methodology are paramount.

1. Use a small very fine attachment (on a Dremel??) or (rig something on the belt sander??) to add a 2-4mm sanded border on the front of the plate.

2. Use a table-top belt sander with a very fine sandpaper to very slightly bevel all four front edges just barely enough to remove their cutting sharpness.

3. Very lightly sand the front-side corners just barely enough to remove their stabbing sharpness.

(all of the above in that precise order)

I'm GUESSING that the elimination of tiny chips and sharp edges along with the addition of the rough area for the emulsion to grab onto would greatly reduce the problem of wet emulsion breaking free from the edges and corners.

I apologize if this is an old idea.

Bill Harrison
06-03-2012, 09:14 AM
If you go to D. Ross's incredible site, The Light Farm, you'll find several methods of dry plate prep that go from simple to very thorough. I'm sure that in combination with her method of edge prep, you'll get impeccable results with wet plate. The old guys really had this down, you almost never see frilling,etc on stuff from the 1800's. Maybe someone has the answer they had.... Reminds me of the old buddist recommendation: "Do not follow in the footsteps of the men of old. Seek what they sought."

Old-N-Feeble
06-03-2012, 09:33 AM
Thanks, Bill. I only searched here and didn't find anything I recognized as similar methodology. I should have tried Google. :)

illumiquest
06-03-2012, 11:54 AM
I use albumen on the edges of my plates and that fixes the edge peeling completely. It's hard to get that stuff off even with your finger nail.

Photo Engineer
06-03-2012, 01:32 PM
When you cut a glass plate to size, the edges are usually sharp. Use of a glassworker's triangular file will remove the sharp edge and also produce a rough bevel. This bevel will do the job of promoting adhesion just fine. The other trick is to use chrome alum as hardener. This promotes better adhesion to the glass than any other hardener.

PE