glueing black plastic...laptop power jack component

[J]

I have a coax laptop power jack that I was able to solder and glue back
together with krazy glue. It broke again. What's the best kind of glue for
the black plastic that these components are made from? Since krazy glue
failed me, I bought some radioshack 'all purpose ashesive'...

Thanks,
-JB

 

[Leonard Caillouet]

Usually some kind of model glue. You will likely have to reinforce the
plastic. What I do is take a piece of lead trim from a resistor or cap and
lay it on the plastic across the joint and just touch my soldering iron to
it and let it melt into the plastic. Do that on both sides and you will
have a stonger piece than before the break. Just make sure that you are not
placing the support anywhere that it might come in contact with a conductor.

Leonard

 

[Jeff Liebermann]

I have a coax laptop power jack that I was able to solder and glue back
together with krazy glue. It broke again. What's the best kind of glue for
the black plastic that these components are made from? Since krazy glue
failed me, I bought some radioshack 'all purpose ashesive'...

I've had good luck with cyanoacrylate adhesive and epoxy. The black
plastic is ABS which should work with just about any adhesive. If
cracked on the sides (as usual), I sometimes sandwitch a thin
fiberglass or plastic reinforcing patch to straddle the crack.

However, methink replacing the jack is best, especially if it's
severely mangled:
http://www.laptopking.com/dcjacklist.asp (overpriced)
http://www.singatron.com/DC_Power_Jack.asp (order from Digikey)

 

[Dan]

I've had good luck with cyanoacrylate adhesive and epoxy. The black
plastic is ABS which should work with just about any adhesive. If
cracked on the sides (as usual), I sometimes sandwitch a thin
fiberglass or plastic reinforcing patch to straddle the crack.

However, methink replacing the jack is best, especially if it's
severely mangled:
http://www.laptopking.com/dcjacklist.asp (overpriced)
http://www.singatron.com/DC_Power_Jack.asp (order from Digikey)

I just repaired my wife's flimsy cell phone charger flat multi-conductor
plug using a method I've found to be successful many times, basically
potting the whole interior portion in epoxy, then snapping the 2 halves
back together & securing until set. Produces a plug much more solid
than the original & also secures the wires inside nicely. Would likely
work with 2 halves of a broken coax plug as well. Basic idea is to just
fill the insides with epoxy.

Dan

 

[[email protected]]

I have a coax laptop power jack that I was able to solder and glue back
together with krazy glue. It broke again. What's the best kind of glue for
the black plastic that these components are made from? Since krazy glue
failed me, I bought some radioshack 'all purpose ashesive'...

Never glue anything without first finding out what kind of plastic it
is, especially since some glues, like krazy glue/super
glue/cyanoacrylate will often stick too poorly to make a strong repair
but too well to be removed and allow a proper repair. If the plastic
is dissolved by lacquer thinner or carburetor spray, it's probalby ABS,
styrene, PVC, or polycarbonate, and it can be repaired by those
solvents or MEK, methylene chloride, or brush-on liquid solvent glue
sold by hobby shops (in a bottle, not a tube). Use scraps of identical
plastic to fill any cracks, and allow 24 hours for the solvent to
evaporate completely. If a solvent repair fails with polycabonate, the
mating surfaces will have to be sanded or scraped to remove the chalky
coating created by the solvent. Plastics that aren't affected by
solvents include polyethylene, polypropylene, nylon, acetal (includes
Derlin) and polyester. Polyester can be repaired very well with krazy
glue or epoxy, but the other plastics need either exotic adhesives
(n-Bond) or have to be melted together with a soldering iron.
Polycarbonate is also repaired well by welding.

You may be able to strengthen any poorly designed part by roughing up
its outer surface and coating it with krazy glue and nylon or rayon.

 

[[email protected]]

JBWeld epoxy has done very well for me. I usually use crazy glue to
put things back together and then use the JBWeld over the original
parts to strenghten things beyond their original design. It's gotten
me through a lot of problems.

H. R. Hofmann

 

[J]

Thanks all for the suggestions. I may do a combination of all that. May
reinforce with a bit of metal, and coat with epoxy after cyanacry? ester...

-JB

 

[[email protected]]

JBWeld epoxy has done very well for me.

I wouldn't use it on any plastic but polyester. It's just high
temperature epoxy.

I usually use crazy glue to put things back together and then use the
JBWeld over the original parts to strenghten things beyond their original
design. It's gotten me through a lot of problems.

I doubt the repairs I made to stripped and cracked gears of a
mechanical TV tuner would have held up for long if I had used crazy
glue or JB Weld on them. The gear made of ABS was solvent welded with
lacquer thinner, the nylon gear melted back together with a soldering
iron and its shaft flange reinforced with brass tubing. The TV still
works, and I probably won't toss it until 2009, when analog TV
broadcasts will supposedly be outlawed.

 

[[email protected]]

Thanks all for the suggestions. I may do a combination of all that. May
reinforce with a bit of metal, and coat with epoxy after cyanacry? ester...

First make the proper repair according to the type of plastic. Then
reinforcing a poorly designed part is always a good idea, but be sure
the reinforcement will be sound. Epoxy sticks poorly to anything but
hard plastic (Bakelite, polyester), so rough up the surface for good
mechanical grip. Epoxy or cyanacrylic glue by themselves don't give
added strength until fabric is added