On 4/28/2015 5:25 PM, Jeff Liebermann wrote:
On Tue, 28 Apr 2015 15:31:28 -0700, mike wrote:

But the stuff has a short shelf life after opening
and I waste 90% of it. Every time I try to use it,
the can contents is solid. I spend $4 on a can of
glue to fix a 25-cent wall wart.

Try removing the air with one of these:
http://www.amazon.com/Ziploc-Vacuum-Starter-3-Quart-1-Pump/dp/B003UEMFUG
I'll admit that I haven't tried doing this, but I've been thinking
about it for fixing the same problem with rubber cement. Try it and
report back.

So, Is there a glue that works well holding wall
warts back together and has a long shelf life?
I have no idea what type the plastic is.

Nope. The brittle glues, like cyanoacrylate adhesive will crack and
you'll have a potential shock hazard. I've done so-so with the
rubbery RTV adhesives (not caulk), but they tend to be messy. They
also have a short shelf life. Even if you don't open the tube, 1 year
maximum is the mfg recommendation.

Looking for a recommendation that you have actually
used successfully.

Solvent welding works. You'll need a syringe applicator to keep from
making a mess. Also, lots of ventillation and gloves. Most of the
plastic cases are ABS but a few are polycarbonate. My solvent of
choice is methyl chloride, also known as paint stripper, which will
work with most thermosetting plastics.

For just ABS, straight acetone, or some plastic scrap dissolved in
acetone works well.
https://www.youtube.com/watch?v=2YIV0XVkkPE
Lots of other YouTube videos on plastic welding.

Your existing pipe glue is a solvent with some thin plastic filler.
The problem is that it's rather weak to prevent softening the pipe if
overused.

I really don't want to unplug the wall wart and find
myself with a handful of AC when the lid comes off.

Get a sticker that says:
"No user serviceable parts inside".

Thanks for the link. I'll try the acetone.

For today's fix, I took the hot air rework pencil out to the
garage. Heated the seam with 360C air and pinched it together with
tweezers to melt it all together.
Doesn't look pretty, but I can't break it apart, so guess it works.