[DonP]

I did some gasket maker work and testing recently (with exactly the blue gunk used in this thread.) Among using it for its intended purpose (making a gasket) I also used it on a leaking GBB magazine, but periodically ripped it apart at different times to investigate how it was going. Yes, this meant I had to do and re-do it many times over but I discovered something important.

Short version:

You need more than 24 hours for the gasket maker to fully cure inside a magazine.

24 hours? Sure, if what you applied is sitting in "open air". When it's inside a GBB magazine it took at least a week (at 18-20C) to fully cure! (Edit: The label on the tube says 24 hours, that's where the number comes from.)

My hypothesis is that oxygen is what's curing it, and when it's in the open air there is plenty to go around and lots of surface area. But as soon as you put it in an enclosed space (like inside a magazine) and pinch it between metal there is no longer much oxygen OR surface area and it cures... but very slowly.

Up to about a week in, the gasket maker gunk -- when used as directed in this thread -- was NOT fully cured. 24 hours was not nearly enough. (My chilly basement probably contributed though.)

The process shown in this thread is awesome. It's a great fix. Far better than anything else I've used over the years. But if you leave your mags for only 24 hours, it is not enough to fully cure inside a magazine.