For years I have used Barge Cement for leather working. For many years I wouldn't use anything else. The last quart of it I bought is almost worthless, though. It doesn't get tacky like it should after a couple coats. It just goes from wet to dry. It won't bond at all. It never gets to the tacky stage. To get it to hold, I have to hammer the holy heck out of it, going back every couple minutes and hammering it again, numerous times, until it finally bonds. I have no idea how it will hold over time.
Last week, in the search for decent cement, I ordered some Master Cement made by Petronio.
Yesterday it arrived and I gave it a try. Two coats, stick together when at the tacky stage and it bonds instantly. I set it with a cobbler's hammer like I've always done. It worked just like Barge used to. I'm pleased and thought I'd pass the word on in case someone is having the same issue with Barge as me. I know there are other good brands of contact cement that work but I've tried a few different ones and haven't been satisfied with them. It seems to be available from numerous suppliers. I got an 8 oz can to try. Next time I get it, I'll order a quart from one of the leather supply houses.