Response by: JP, April 13th 2018 3:57:03 pm
Cleaning - many solvents can damage latex, so be careful. The solvent MJ Trends sells for their solvent-based cement works very well for cleaning, too. Heptane is an excellent solvent, but make sure you're getting a good grade to avoid contaminants that might attack the latex.
You want the adhesive to dry completely before attaching seams -- it should be just a tacky film on the surface of the sheet, not liquid at all. If you're using solvent based adhesive, you'll see the surface texture change, it will shrink to a much thinner film, and the swelling/curling caused by the solvent will go away so the sheet lies flat on its own. With water based adhesive, it will go from white to fully transparent. If there's any solvent or water left in the adhesive when you stick the surfaces together, it will stay trapped in the cement for a long time, weakening the joint. (It will *eventually* evaporate out through the material, but the joint could be weak for days.)
When using general-market rubber cements like Best, you want to make sure you're getting an acid-free "archival" grade. Browning and rot are driven by sulfur compounds and acids in cement that isn't intended for permanent use on sensitive materials.