Gilding: It is best to keep plates in distilled water until gilding. This is particularly
true for Becquerel plates. Drying the plate and re-wetting before gilding creates the possibility of staining or having contaminates on the plate. A gilded plate has a surface more
conducive to water removal and drying. Also, since gold chloride is not cheap you must decide whether the image is worth that cost. Additionally, a gilded image is very difficult
to buff off. Whichever, if a plate is dried prior to gilding it is best to re-wet by hypo first, then rinse, and then into distilled water.
The image, after development, is already in a fixed state but unexposed iodine
must be removed. This residual iodine is dissolved by putting the developed plate into a solution of sodium thiosulphate under the safe light or dim light. Thin coatings take less
than a minute and thicker coatings will take longer. Watch the film dissolve away to make sure it is all gone before proceeding on. Prematurely drying a plate with iodine
left on the plate will have dark cloud-like patterns. Rinse the plate in tap water then put the plate into a tray or beaker of distilled water before deciding what to do next.
Always prepare fresh hypo each day of use because old fix will produce black spots on the final image.
Unused sensitized plates should be cleared in hypo before re-polishing.
A glass, teflon or heat resistant surface can be used for gilding or by using the traditional gilding stand. Whichever method, it is important that the gilding solution completely
cover the plate at all times. Since the plate is heated any dry spots will cause staining on the final image. A hot plate works for trays or alcohol lamp or propane torch with the
stand. Generally, the solution needs to be heated until steaming and bubbles are forming.
Extended gilding adds warmth to the image tone. The critical issue in gilding is watching the stains. They will appear as the solution heats up and portions or all of the
image will turn darker. This is easier to see while viewing the process in the negative--reflecting off a white surface, such as the ceiling so the black of the image appears
white. Heating must continue until all the dark areas lighten and disappear. Stopping midway will show these stains on the finished image. Finally plunge into water or pour
water over to cool and rinse the plate and then place in distilled water.
As the plate is taken out of the distilled water prior to drying, a squirt bottle with distilled water should be used to further rinse the plate to remove any possible contaminates.
Then, using a blow dryer on high setting, start at one corner with the opposite corner down and blow the water off the plate.
Examples of gilding and drying equipment