Originally Posted by
dddd
Most agree that the solvent has changed over the years, but how do you know what it is?
The solvent hasn't changed since I've been using it. As a chemist, I know what the various aromatics smell like. Toluene and xylene have a very characteristic odor.
Originally Posted by
dddd
WRT contamination from the surface of the plastic, any micro-layer of mold-release would not remain as a detrimental microscopic film, but would be miscible in the wet glue thus preventing it from having any significant effect on bond strength. Solvent-based glues are very good at dispersing any contamination "film" as long as the glue is agitated on the surface, and in any case the plastic wrap is not left between the tube and the patch. The plastic protects your finger while preventing skin detritus, moisture and oils from contaminating the glue.
It's not any release compound...there probably isn't any...that causes the problem but the plastic itself. The plastic is soluble in the solvents and could interfere with the bond. It's also an unnecessary step because the solvent will evaporate by itself.
Originally Posted by
dddd
You have to spread the glue around, else the glue would be dripping off the tube and the drying time would be enormous. Most patchers have noticed this I'm sure, that an even layer dries fastest.
How much are you using? If you are putting on enough that it's dripping off, you are putting on way, way, way too much. A 2 oz tube should be enough for many...10 at least...patches. Yes, you need an even layer but you need a
thin even layer.