On 5/1/2015 4:49 PM, Michael Black wrote:
On Fri, 1 May 2015, mike wrote:

On 5/1/2015 10:35 AM, Cydrome Leader wrote:
mike wrote:
On 4/29/2015 1:53 PM, John-Del wrote:
On Wednesday, April 29, 2015 at 3:21:02 PM UTC-4, Cydrome Leader
wrote:
mike wrote:
On 4/29/2015 4:40 AM, Mike Tomlinson wrote:
En el art?culo , mike

escribi?:

So, Is there a glue that works well holding wall
warts back together and has a long shelf life?

Superglue (cyanoacrylate) works well for me, but don't buy the
cheap
stuff.
Superglue scares me for something that can electrocute me.
Works great when it sticks, but doesn't stick well to some plastics.
When I'm fumbling around in the dark under the desk, I really,
really
want the wall wart to come out in one piece.

Getting the wall-wart apart neatly is an art form in itself. I
use a
bench vice (with protectors if the vice jaws are serrated) and
try the
wall wart in various positions, tightening the vice to probe for
the
weakest part of the joint. Once you get the seam separated at one
point, the rest is easy to gently crack open.

I've never had much luck with that. End up tearing the plastic
instead of separating the joint.
I use a wood chisel to whack the seam sharply. Splits nicely, but
does break a lot of the overlapping plastic. With the plumbing pipe
glue, I can get it back together with reasonable aesthetics.

It takes time, but I read on a newgroup you can hold the power
supply and
just beat on it with a hammer all around the edges over and over
again and
it will split open, like a nut.

It does work. I told the power supply in fluffy glove and whack at
it with
a small hammer. All the little whacks crack the welds inside.
Everything
pieces together nicely with no stretched or deformed parts like
you get if
you chisel, cut or pry thing thing open. The tough things like laptop
power supplies will open up this way if you have several minutes.

Some come apart easily, and some will never come apart without a
lot of effort. Those that appear to be really welded together are
the ones I'll just zip down with a Dremel and cut-off wheel (making
sure to not go too deep).

If fixed, I'll either run some solvent in the seam if it came apart
cleanly, or stuff it with RTV and rubber band it for 24 hours.
BTW, you can make a nice RTV seam by wetting your finger with oil
(or spit) and wipe it down to a smooth shiny fill.


RTV has the same shelf life problem. And it's GAWD awful expensive.
All the stuff I've found at reasonable prices or at the hardware store
exude acetic acid.

The RTV type 2 stuff smells like alcohol, not acetic acid. I just make
sure to get a tube that has a good cap that won't clog up and can be
resealed nicely. The GE branded stuff in plastic tube works well. The
last
tube had to be around $4 at home depot.

Got a part number?
The GE Silicone II seems to say, non-corrosive, but there are additives
for mildew resistance and color change while curing etc. that may or may
not be good for electronics.
There's a zillion choices with very little info.
Some of the stuff says, "use on aluminum, copper, stainless...",
but when you finally find spec, it's acetic acid based.

Still, all the ones I've found that actually say, "safe for electronics"
are $30 for a 3oz. tube, 99% of which I'm gonna watch harden in the tube.

An actual part number for a product you've actually used successfully
on electronics would be helpful...until they change the formula...sigh...

I realize some of the problem is in the curing, and in a tight space
some of what dissipates during curing may cause problems to metallic
components.

But there has to be a distinction between glopping this stuff over
electronic components to insulate them (or hide them away so the
competition can't see what you're doing) and sealing up the casing.
The former seems very finicky, the latter less so. But I don't know how
much less so.

Michael

Back in the day, I built a pirate TV receiver. Sealed the box with
household caulk. About a month later, it quit working.
Opened it up and youda thunk it had been under seawater for years.
Corrosion everywhere. Had to trash it and start over.