Has anybody noticed that Super Glue (cyanoacrylate clear liquid glue) just
doesn't seem to work any more? I remember when it first came out that it
used to bond anything and everything. Lately, seems that I can't even fix my
son's toys with it any more.

Latest failu Just tried to glue a small 12V DC fan for a PA with it and
the bond came apart the next day pretty much by itself.

Al W6LX

Switch to two-part epoxy. You will, however, have to wait for it to set.

"Al Lorona" wrote in message
...
Has anybody noticed that Super Glue (cyanoacrylate clear liquid glue) just
doesn't seem to work any more? I remember when it first came out that it
used to bond anything and everything. Lately, seems that I can't even fix
my
son's toys with it any more.

Latest failu Just tried to glue a small 12V DC fan for a PA with it and
the bond came apart the next day pretty much by itself.

Al W6LX

In article ,
Al Lorona wrote:

Has anybody noticed that Super Glue (cyanoacrylate clear liquid glue) just
doesn't seem to work any more? I remember when it first came out that it
used to bond anything and everything. Lately, seems that I can't even fix my
son's toys with it any more.

Latest failu Just tried to glue a small 12V DC fan for a PA with it and
the bond came apart the next day pretty much by itself.

There are certain specific plastics (polyethylene, polypropylene, and
Teflon) which most cyanoacrylates will not bond to properly (either at
all, or without some specialized surface preparation). I believe that
these plastics are characterized by low surface energy.

If what I read in some of the trade journals is any indication,
manufacturers have been selecting newer and more specialized blends of
thermoplastics and thermoset plastics over the past few years, in
order to optimize the cost, strength, impact resistance, etc. of their
products. It would not surprise me if you're more likely now, than a
few years ago, to run into plastic-resin blends which cyanoacrylates
have difficulty "getting a grip on".

A web page at Saf-t-lok indicates that "Surface ionization
pretreatment is necessary to affect best results with instant bonders
on non-polar plastic surfaces such as polyethylene or polypropylene.
SAF-T-LOK® Surface Conditioner does the job."

Cyanoacrylates also vary significantly in their "grabbing"
aggressiveness, viscosity, gap-filling strength, and their tendency to
bloom (emit the classic eye-searing white fumes which then "frost" the
surface around the application point). My impression is that the
newer non-blooming formulations may not grab as aggressively, or hold
as strongly as the classic variety. None of them seem to be
particularly good in gap-filling strength, unless you add an
additional particulate filler (baking soda is sometime suggested).

Abrading the surface with fine-grit sandpaper, and then degreasing
with isopropyl alcohol, can improve the grip significantly.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

ORIGINAL MESSAGE:

On Tue, 7 Nov 2006 16:31:36 -0800, "Al Lorona"
wrote:

Has anybody noticed that Super Glue (cyanoacrylate clear liquid glue) just
doesn't seem to work any more? I remember when it first came out that it
used to bond anything and everything. Lately, seems that I can't even fix my
son's toys with it any more.

Latest failu Just tried to glue a small 12V DC fan for a PA with it and
the bond came apart the next day pretty much by itself.

Al W6LX




------------ REPLY FOLLOWS ------------

FWIW: Super glue should only be used for temporary fixes. Even though
it may be strong enough when first applied, it gets brittle after
about a year and loses much of its strength.

Bill, W6WRT

Al Lorona wrote:
Has anybody noticed that Super Glue (cyanoacrylate clear liquid glue) just
doesn't seem to work any more? I remember when it first came out that it
used to bond anything and everything. Lately, seems that I can't even fix my
son's toys with it any more.

Latest failu Just tried to glue a small 12V DC fan for a PA with it and
the bond came apart the next day pretty much by itself.

Many modern plastics are not effectively glued with plain old super
glue (Well, for me modern is anything newer than Bakelite). There are
some CA glues that include special activators to help stick to these
plastics but they aren't magic bullets, they turn a failed joint into a
marginal joint.

If you can rough up the surfaces involved (using more area than just
the broken joint) and use a glue that will give a good fillet around
the joint, that'll help. There are thick super glues and epoxies that
help there.

It's very odd that a fan blade would have broken off all by itself.
Usually indicates some sort of mechanical interference (guard loose,
maybe bearings so worn that it's rubbing against something else.)

Tim.

Al Lorona wrote:
Has anybody noticed that Super Glue (cyanoacrylate clear liquid glue) just
doesn't seem to work any more? I remember when it first came out that it
used to bond anything and everything. Lately, seems that I can't even fix my
son's toys with it any more.

Latest failu Just tried to glue a small 12V DC fan for a PA with it and
the bond came apart the next day pretty much by itself.

Al W6LX

FWIW, I've found a product called "Plas-T-Pair" to work in a lot of
cases where "super glue" won't. Also, I've been using LocTite 444 "Tak
Pak" alpha cyanoacrylate for other things, as it seems to work better
than the thin mass-marketed superglues. LocTite 712 accelerator makes
it set up quickly. In addition, any joint with stress (esp. tension)
on it I'll augment with reinforcement of some sort. Lots of things
work: embed a little scrap of cloth in the joint, drill mating holes
and put in a peg made from wood dowel stock, or threaded rod (a cut-off
machine screw, for example), or roughed-up steel wire, or even copper
wire. Even wrapping sewing thread (or small steel wire) around the
joint (if the geometry lets that work, so the thread crosses the joint
multiple times) works wonders. Apply the idea of reinforcement
creatively and you'll pretty much always get a much stronger repair.
Even embedding chopped-up fiberglass in the glue will help. Hint:
superglue alone is probably going to be fine in compression, so long as
it's not subject to shock or excessive mositure, but in tension, it can
benefit a lot from some help, especially if it adds reinforcement where
the glue joint to the original pieces becomes shear instead of simple
tension--i.e., adding pegs in holes.

From your post, I'm not sure just what part of the fan you were gluing.
If it was a broken blade, I'd expect to need to be very careful with
the repair because there's a lot of stress on the blade when the fan is
running, and adding mass will imbalance the blade if you're not
careful.

Cheers,
Tom

Al Lorona wrote:
Has anybody noticed that Super Glue (cyanoacrylate clear liquid glue) just
doesn't seem to work any more? I remember when it first came out that it
used to bond anything and everything. Lately, seems that I can't even fix my
son's toys with it any more.

Latest failu Just tried to glue a small 12V DC fan for a PA with it and
the bond came apart the next day pretty much by itself.
============================
Super glue (cyano-acrylate) works on the basis of 'exclusion of oxygen'
at the joint ,hence it can often be used effectively for rejoining
broken crockery.

With plastic the break surface is often less 'crisp' especially when
interfered with by tools /sandpaper. Hence an expoxy type of glue is
then more appropriate .

Some plastics can be jointed by hot glue dispensed by a hot melt gun
provided it is done carefully and there is a reasonably large jointing
surface.

Polystyrene can be best (re)jointed with polystyrene glue as used for
model making , or acetone (nail polish remover) when the material at
the joint is dissolved locally by the acetone (a solvent).


Frank GM0CSZ / KN6WH

Thank you all for your replies. Tom's treatise on reinforcement was
well-taken on this end and is something I am going to try in the future.

The opinion seems to be that Super Glue has not really changed but that
plastics have changed into a form not as easily repaired by Super Glue.
However, judging from the way Super Glue used to bond my skin vs. how much
less so now, I still suspect that a weakening of the formula may have taken
place, perhaps in response to a lawsuit by someone who accidentally glued
the palm of their hand to the sole of their shoe or something ridiculous
like that. Lawyers are continually ruining products and processes for the
rest of us as they search for the next target from which to extract punitive
damages.

By the way, I never said what kind of failure it was; someone else assumed a
fan blade had cracked. Actually, it was one of the supporting struts that
had cracked. I am fairly confident that with some reinforcement a crack like
this one has a very good chance of being repaired. However, I believe epoxy
is better indicated in this particular case as one of the posters pointed
out. Epoxy is one tough glue.

Thanks again.

Al

"Al Lorona" wrote in message
...
Thank you all for your replies. Tom's treatise on reinforcement was
well-taken on this end and is something I am going to try in the future.

The opinion seems to be that Super Glue has not really changed but that
plastics have changed into a form not as easily repaired by Super Glue.
However, judging from the way Super Glue used to bond my skin vs. how much
less so now, I still suspect that a weakening of the formula may have
taken
place, perhaps in response to a lawsuit by someone who accidentally glued
the palm of their hand to the sole of their shoe or something ridiculous
like that. Lawyers are continually ruining products and processes for the
rest of us as they search for the next target from which to extract
punitive
damages.

By the way, I never said what kind of failure it was; someone else assumed
a
fan blade had cracked. Actually, it was one of the supporting struts that
had cracked. I am fairly confident that with some reinforcement a crack
like
this one has a very good chance of being repaired. However, I believe
epoxy
is better indicated in this particular case as one of the posters pointed
out. Epoxy is one tough glue.

Thanks again.

Al

Al,

You had the best answer. I never seen so much bs in a thread. When the glue
first came out it was not uncommon for the emergency rooms around the
country to have patients with eyes glued shut. Just like the 84 year old
lady who successfully sued McDonalds because of burning her crotch with
their hot coffee. Now they serve their coffee at a lower temperature.
Doesn't taste as good.

Cordially,
west

"west" wrote in message news:r0leh.39$495.3@trnddc06...
You had the best answer. I never seen so much bs in a thread. When the glue
first came out it was not uncommon for the emergency rooms around the
country to have patients with eyes glued shut.

I remember reading the MSDS for super glue many years ago and it specifically
mentioned that it wouldn't actually harm your eye, and the best thing to do
was just wait until the skin naturally dies rather than trying to force open
the lids. Ewwww....

I'm sure it stings like a @#$@ though; just getting my eyes close to the stuff
makes them sting from the fumes.

Just like the 84 year old
lady who successfully sued McDonalds because of burning her crotch with
their hot coffee.

Just to be fair to Ronald, the particular McDonalds in question was serving
their coffee considerably hotter than they own internal guidelines said they
should have been.

Now they serve their coffee at a lower temperature.

Definitely a case of one bad apple (the restaurant) ruining it for everyone.