I am pretty sure contamination is an important factor. The acetone cleaning
ritual
certainly helps for me. However, don't forget another factor and that is the
curing of the epoxy. Sure, after a few hours it gets hard but it is by no means
cured. The full process can take weeks, even months in which longer and longer
polymer chains are formed. In fact without a post cure it never really finishes-
which is why we do it of course.
I would not be surprised if this also plays an important role in bonding to the
substrate. Part of the bid tapes on my firewall came off practically by looking
at them. I redid those parts, but all tapes are now solid as a rock.
Message: don't panic if the bid can be easily taken off the next day. Give it a
week or more and only then decide if you really need to rip it all out.
Jeroen
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=295908#295908
|