Glue Question

[DONALD G]

Hello,

After 25+ years of hard use, I have developed a problem
with one of my L100 speakers. When turned up I hear
a "snapping" noise out of the 123a. After closer inspection
I found that the cone is starting to separate from the spider.
Doing a search of this forem, the best advice was to use a
carpentry type cyanoacrylate glue which I have not been able
to find ( not at home depot,lowes or the local hardware
stores ). Does anybody know of a specific glue that they
have used, and where to buy it ? Has anyone used the speaker
repair glue that parts supply sells ( 340-076). Any help
would be greatly appreciated.

Don

[Robh3606]

I had a similar problem where the spider was seperating from the coil/cone base. Its hard to get at to make sure it gets glued in the right position. What I did was remove the magnet assembly from the frame, reglue with the surround glue. You can get it from Parts Express. And just carefully put the magnet back on the frame. There are two alignment keys/pins in the frame so if you are careful it can really not be a big deal. Just make sure you mark the frame with an index mark so it goes back in the same oreintation. They are offset so you really can't get it back together wrong just be careful you don't damage the voice coil. If you are not comfortable don't do it. You can always bring it to a JBL service center if you have one close by to see if they can fix it. Attached is a photo of a spare 123A frame with the magnet detached.


Rob:)

[subwoof]

2 part epoxy is the preferred glue for that junction - the glue that you mentioned ( the hard to spell one ) is the basic crazy glue......

you will *want* the set-up time that epoxy affords....

:)

sub

[boputnam]

Originally posted by DONALD G
After 25+ years of hard use...

I agree with subwoof on the need for lengthy setup time - you've got to make sure things are all properly centered.

But, I question the entire exercise. If one woofer has this damage, assuming you've not been monaural, the other 123A has seen the same signal pattern.

I suggest a recone on both LF's if you're fond of the original sound those L100's produced...

[DONALD G]

boputnam you are right - I purchased 2 pair of L100s in
the mid seventies, and three out of the four base speakers
are starting to show a split between the spider and cone,
but only 1 sounds bad. The snapping noise only occurs at
high volume and when the bass is strong - bass drum.

The split is only about 20 % of the circumference of the
cone / spider joint, and is hard to see unless you push
the cone out and look carefully. Because of this I don't
think i will have a problem with keeping the cone centered
during the repair. Pulling the magnet was easy, which gives
me a clean shot at the joint. Thanks to Robh3606 - my original
plan was to try to do the glue job without taking the speaker
apart. That would have been a mistake. I ordered a tube of
cyanoacrylate gel glue from parts express - the saleman confirmed
that this would be the best glue for the job. A small bead of glue
around the joint should do the trick.

I surely can't be disappointed with my purchase of these speakers
The ink stamp on the inside of the voice coil - JAN 15 1975

[jbl]

I bought my pair of L-100 in November 1975. They were one of if not the best sounding speakers in their size class at the time, regardless of price. They still sound great after 28 years.

[boputnam]

This is really a dangerous Thread for me... :slink:

:rotfl:

[Ian Mackenzie]

Resist the Temptation Bo,

It also epends on how often if ever you have your ears waxed Giskard.

Ian

ps wheres Tooths...:snore:

[boputnam]

Originally posted by Giskard
I'd advise you to dump those 4345 battleship anchors you have and do the same. :yes: Actually, I fought the urge to reveal this to Ian - he was so anxious to build those lame refridgerators - but the 4345's are fraud. I discovered this collecting measurements for Ian.

There's really four L100's stacked in each cabinet...

:nutz:

[Ian Mackenzie]

Yeah,

I got my pair the Altec Duplex 604 ((L100's) emulators flanking the main coolers.

So why have you dismantled those much loved 4430's? What surround sound amp are you using?

Ian

:confused:

[boputnam]

Giskard...? :confused: Dammit - we almost had him!!

That was his desperate call for :help: ... He was just about to admit that he is "thoots", and in truth simply fawns over his 12-dozen pair of L100's...

;)

[jbl]

Bo and Ian. I knew you could'nt resist responding in some way about an L-100 question. Just wanted to see how easy it was to push your buttons.

[boputnam]

Originally posted by jbl
Just wanted to see how easy it was to push your buttons. :rotfl: Yea, well you shook Giskard from the bushes, too, but the rascal vaporized hisself... :beamup:

[DONALD G]

Hey if it were not for all of us chumps that bought
the L100, JBL would have gone out of business
and you guys would all be sitting around trying
to fiqure out how high you could stack your advents
and wondering if your sansui 9090 could handle .005 ohm.

All of us L100 owners should start our own forum
and not let you guys play. NA NA NA

[Ian Mackenzie]

This thread should be titled the chain reaction.

Sounds like Giskard building a 4344 out of the 4430 scap parts?
Why else would he dismantle his 4430's?


Ian

:duck:

[DONALD G]

WOW
I have only been a member of this forum for less than
one week and have managed to offend one of its most
respected senior members.

I better do a yahoo search and find a cervin vega forum
I can join. I think i still have a pair in the attic.

Giskard have you ever shot a L100 with a ak-47 ?
I bet you want to.

[Ian Mackenzie]

Cool idea,

3 db more sensitivity and new boxes, wouild you try and blend the 1500 sub?

Ian

[Ian Mackenzie]

Yeah ,

Well if you can crossover low enough, then you have flexibility with the sub placement ect so could get best imaging and low end...best of both worlds.

I was toying with that idea my self while back using the smaller version of the 2344 from the 4425 and say even the 2118s in vented boxes for small L+ R front & rear and centre.


Anyway good luck with your transformation....but I would save the 4430 boxes.

Ian

[ARG]

Originally posted by DONALD G
Hello,

After 25+ years of hard use, I have developed a problem
with one of my L100 speakers. When turned up I hear
a "snapping" noise out of the 123a. After closer inspection
I found that the cone is starting to separate from the spider.
Doing a search of this forem, the best advice was to use a
carpentry type cyanoacrylate glue which I have not been able
to find ( not at home depot,lowes or the local hardware
stores ). Does anybody know of a specific glue that they
have used, and where to buy it ? Has anyone used the speaker
repair glue that parts supply sells ( 340-076). Any help
would be greatly appreciated.

Don
Hi Don;
I have been building and rebuilding for years , obviously I like blowing up drivers .
Anyway I recently found a glue thats almost perfect for older drivers , it is a polyurethane based (general pupose glue) made by Lepage ( available in Canada , not sure about the U.S. )
It comes in small 118 ml bottles and has a UPC of 061083 002909
This glue has some great properties .
You require very little to get the job done .
Use a tooth pick to spread on small drops of the product , then wait . The glue produces micro bubbles when it goes through the curring process which takes roughly 48 hours , because this glue is a poly urethane it will always remain slightly flexable yet very strong .
Cyranoacrilate is not any good for speakers its far too brittle to take the vibration and most 2 part epoxies suffer the same problem unless they have been stabized for vibration ( flexable formula) .
The Lepage polyurethane produces a great result , strength and has good dampening sharacteristics because of the micro bubbles that set up during the cure process .
Anyway thanks my 2 cents worth !
Cheers ....ARG

[DONALD G]

ARG,

I used that cyanoacrylate glue yesterday on all
3 of my 123a-1's that had the spider problem,
and so far so good. The fan on my crown ce-2000
has been on all afternoon and nothing has come
loose yet. I ordered a different glue that the salesman
at parts express recommened, but it seems just
like elmers white glue. He said it was good for foam
surrounds.
I looked at lepages website for that glue but didn't
find it. I'll have more time tomorrow. I go to windsor
every month or so and i'll pick a tube up to use as
a backup if the super glue fails if its only available
in Canada. I appreciate your 2 cents worth.

Don

[John]

Hi Don If your in Windsor go to Canadian Tire they stock that glue. You will find it in the paint department. The full name is

Lepage Polyurethane Universal Adhesive. I think it sells for about 4 to 6 dollars canadian.:D

[GordonW]

Cyranoacrilate is not any good for speakers its far too brittle to take the vibration and most 2 part epoxies suffer the same problem unless they have been stabized for vibration ( flexable formula)

Um, I don't know about this.

For one example, Peavey has been using cyanoacrylate on almost ALL of their speaker assemblies, for years now. I am good friends with the busiest pro reconers in the area here, and they've NEVER seen a Peavey driver, no matter how abused/blown/overworked, that the cyanoacrylate glue joints failed in. I've also used it EXTENSIVELY in rebuilding drivers, as has the other reconer around here, on not just Peavey drivers... and after several years of implementation, there's never been a problem.

In fact, on some repair parts, I've seen EVERY other type of glue fail, EXCEPT cyanoacrylate! There are certain materials used on voice coil formers, in rare cases, where the standard glues (EV black glue, Waldom adhesives, etc) simply WILL NOT adhere reliably. OTOH, the cyanoacrylates will "bite"... reliably and STRONGLY, even to these parts.

BTW: These cyanoacrylates we're using, in a large part in reconing, are the ones referred to above... they come from Wood Finishers Supply, under the Original Masters Magic label. They're not listed on the WFS website for some baffling reason (I looked!), but I can say, they're READILY available at the actual WFS retail stores!! Why they don't have them listed online, I dunno WTF is going on there!

As for epoxy- Cerwin-Vega uses lots of epoxy, and on their replacement cone assemblies, especially the 188 and 189 18" pro woofers. I DO NOT believe they vibration cure it. Also, the epoxy they uses, is a dead-ringer, from a property standpoint, to JB Weld and the like... VERY hard stuff. However, I've never seen one of them fail, from an adhesive-related problem...

[DONALD G]

Hey Gordon,

It was your reply to a mid january thread that convinced me to try the cyranoacrilate glue in the first place. I went to all the local lumber yards looking for it, but the only thing I could come up with seemed to be the basic crazy glue - to thin. The cyranoacrilate gel thats parts express sold me hopefully will work.
I very much appreciate your input.

Don

[jbl]

[QUOTE]Originally posted by DONALD G
[B]WOW
I have only been a member of this forum for less than
one week and have managed to offend one of its most
respected senior members.

All insults are by appointment only. ("I have an appointment to insult Ambassador Trentino").

[DONALD G]

I can't afford to p*ss anybody off. I have spent lots
of money the last few weeks on speaker components,
and I'm going to need help putting my project together.
Oh boy, what have I done...

[4313B]

I don't think you've p*ssed anyone off. That Cerwin Vega remark might have caused a few dry heaves :barf: but that's to be expected :rotfl:

I think everyone here is up for offering whatever help they can to anyone who wants help.

[DONALD G]

Appreciate that - time for a new thread.