damn, that's a shame!

[Diablo]

Nice pdf from Loctite here http://www.henkelna.com/us/content_d...ives_Guide.pdf

Anyone know who sells recone parts for CTS drivers? I'm in the process of buying some weber parts that might fit but I'm not sure they have a VC that will fit the gap on this 12 inch. It came out of a polytone and the driver is pretty much "shoe horned" in there with the amp chassis and reverb pan.

I reconed some forty year old CTS 12" ferrite speakers using parts from Weber. I seem to recall using 1.5" voice coils, and they fit fine.

[J M Fahey]

Yes, the original Fender speaker was a Jensen , and "new kids on the block" trying to get the yearly contracts for thousands of speakers basically cloned them, thus providing "the same for less".

So ask for a VC which will fit the equivalent Jensen (1" for "R", 1.25" for "Q", 1.5"for "N" ) and you will be fine.

Besides, Weber has reconed so many thousand speakers by now that specifýing it's such and such Oxford will surely help.

As of adhesives, the absolute minimum is some (good quality) Elmer's glue for almost everything and some 2 part epoxy.

If you can get the kind that cures overnight, much better, it'll let you work at ease; if not, use 5/10 minute ... but mix just what you will use *now* and you actually have 2 minutes to apply it, then its starts gelling.

Apply it with a toothpick or thin wooden skewer, because it's more of a paste than a liquid.

The best is the slow Industrial type, thick as honey, and not more expensive than the common household one, just more difficult to get.

Do not use the one sold specifically for model plane building, it's easy and nice to apply, wets surfaces well ... and does not stand temperature at all

[J M Fahey]

..

[bsco]

Hey J.M. You mentioned Elmer's glue.....if that is the case what about the Lepage's white glue that woodworker's and cabinet maker's use.....Would that also work?? Just a thought I figured I'd throw out there...This stuff is pretty strong once it sets up....

[gbono]

Lepage is a PVA LePage / LePage® Wood Glues / LePage® White Glue though Lepage doesn't recommend using it on non-porous surfaces.

The CTS driver I'm working on has a 2" VC and Weber isn't guaranteeing that they have something that will fit. It's a pretty low cost risk to try though. My other challenge is getting the VC positioned in the cone/spider so the VC will not bottom out. etc. I'm going to use the old assembly as a guide. Though I'm open to any other ways to measure the assembly, jig construction, etc.

[big_teee]

On the Elmers glue, I like the Elmers Carpenters glue.
It dries hard is resistant to most things.
T

[Tom Phillips]

This discussion about the various glue types used to build / recone speakers got me thinking about several old Jenson speakers I have seen that had spider to frame glue joint failures. The attached photos show a sad failure of a 1959 Jensen P12R from a Fender Tweed Deluxe. The owner purchased the amp in 2009 and it was in working order. After a few minutes of use the owner reported that the sound degraded to a very low volume distorted buzz. When I received the amp I found the speaker in the condition as shown in photo 01. The bit of copper color in the center is the voice coil which has jumped out of the gap because the spider came loose from the frame. The cone was brittle with age and probably had some cracks started but it really tore up when the voice coil blasted out of the gap. Photo 02 shows a better view of the voice coil. After it was ejected from the gap it came back down and jammed at a cockeyed angle above the magnet structure. The wiring was still intact and there was enough magnetic field present to make it vibrate when the owner tried to play the amp.

I have seen several other old Jensens with the same type of glue failure. This one did last 50 years so I guess we can’t complain but it is something to consider when buying or using old speakers reported to be in original condition.

[bsco]

Wow....it lasted 50 years....I'd say that's pretty good.......I have seen some new ones that didn't last pissing time....and they were brand new installed by the manufacturer into brand new amps.....Some of the speakers were even seized up solid only after a few months....I do realize that this has a lot to do with how they are being pushed but to get a speaker to last that long is great.....if the glue used in this was sub-standard it is still good glue to last this long...... I have seen a couple of fairly new ones where the surround had let go due to faulty glue...but I haven't seen the spiders let go...then again, I have not been at this as long as you guys have...

[bsco]

I have a question for somebody...I have a 15" speaker that came out of a PA bass cabinet....not sure of the power rating but it is fairly hefty. The surround is let go in a couple of places where the acordian surround meets to speaker cone.....looks like it actually cracked..........it would be great if this could be repaired even if it was installed into a cabinet that handled less power rather than toss it....What would you guys suggest as a repair adhesive for this?? Elmer's or Lepage's white glue maybe??? or some other more exotic adhesive......just want to get your thoughts on this.....it would be a shame to have to throw this out....I would probably keep it and use it for testing...put it in a cabinet or build one......I don't want to throw it out....
Cheers,
Bernie

[Chuck H]

Being a PA speaker it probably has a rubber or even a urethane foam surround. Automotive RTV gasket sealer works alright for repairing those surrounds. If it's an impregnated paper surround you can use coffee filters soaked in rubber cement. As many layers as seems right. If it's a plain paper surround you can use several layers of tissue paper with a light coat of thinned Elmer's glue between each layer. If it's a paper surround with doping just do the tissue repair and then brush a coat of rubber cement over the repair.

[J M Fahey]

Wow, many questions for a single day!!
1) @ bsco: FWIW I live in Argentina, so never actually used Elmer's (brand) glue, even less Lepage (brand), I mention it only as a "famous brand" but anyway what matters is that it's the white PVA-in-water emulsion which dries transparent if pure and whitish if it has solids added.
Buy any reputable , carpenter's approved brand and you'll be fine.
The kind to avoid is the one sold for young schoolkids which to make it easy to wash off clothes has cornstarch added so it's much weaker.
So buy at a carpenter's supply, not at your friendly multipurpose corner store.

For that loose cloth edge, working some carpenter's glue inside the void space with a toothpick and pressing an few minutes until it stays there will be fine.

Elmer's glue is somewhat elastic, nitro based is hard and brittle.

2) @ gbono:
As of 2"voice coils, Weber offers these, which probably should work, specially if your speaker is American (Europeans/Japanese might have Metric ones)
vc2015_4 VC, kapton, 2.015" ID, 4 ohm, 1.42" ht, 80 watt $2.30
vc2015_8 VC, kapton, 2.015" ID, 8 ohm, 1.42" ht, 80 watt $2.30
vc2015_16 VC, kapton, 2.015" ID, 16 ohm, 1.42" ht, 80 watt $2.30

3) @ Tom Philips: being a '59 or earlier, that speaker was built using *only* "speaker cement" which is the nitro lacquer I mentioned earlier.
Nothing else was available !!!
It dries real brittle, much more so after many years, and to boot stamped metal surfaces rust, so adhesion is lost.
I have seen/repaired tons of speakers like that, even some where suspension and cone fould be pulled "by hand" from the frame, go figure.
That said, that speaker was *abused* way beyond putting original amp controls on 10.
Maybe he connected it to some SS amp "just to check it" and the turn on thump did that; just playing full chords on a 10W amp (or 40W for 4 of these) would never have torn it that way.
Oh well.

[bsco]

@Chuck...looks like the speaker has an impregnated surround...along with the doping??...(looks like it has that "wet" look to it)......not a rubber one....
@ J.M. thanks for the reply....I have some Lepage's carpenter's white glue here.....If I use say tissue paper to strengthen the repair, I would like to have it black like the cone is to begin with......maybe put the paper on the underside so it is not readily visable.....I guess then I could coat the surround with a thin coating of this rubber cement to give the repair and the entire surround an added insurance of support...Or is there a special black coating made for this?? Sorry for all the questions but this is the only way I am going to learn...
Cheers,
Bernie

[Chuck H]

There IS a black rubber gasket sealant. There is also black silicone cailk. Either will work as doping over the patch. It may be a paper surround with heavy dope. It may even be some sort of impregnated fiber cloth. Use coffee filters soaked in rubber cement. Do it one layer at a time, allowing to dry in between applications. However many layers seem right. Then dope with the black stuff. When applying the layers try to duplicate the surface profile. It's not as hard as it would seem if you cut the strip edges with a radius.

[bsco]

Ok. Thanks for the advice....I'll have to pick up supplies and try it later the weekend when I have some free time....
Cheers,
Bernie

[J M Fahey]

Commercial rubber cement (doubt you'll mix your own ) has an added chemical to react with air oxygen and further harden it.
Which is good if you applied veneer or Tolex to a cabinet.
Compare pulling Tolex for recovering 1 month after application to same 1 year later.
Now in a speaker, although originally looks good, it may crack one year later.
I prefer white glue mixed with tissue paper, which is water based, impregnates cone paper better (it's much closer chemically) and never "overhardens".
To make a black paste add a "tea" spoonful of latex/acrylic water based black paint (I use Sherwin Williams Loxon, also available in USA) to one "soup" spoonful of white glue and then mix it with tissue paper to add fiber or use it to build layer over layer as chuck h suggested.
Mix will be grey, but will dry black.

By the way I use gallons of black Loxon to paint cabinets, because it dries quickly, without smell, and hands/brushes/rollers/spills can be washed with soapy water.
PA rental companies also paint their cabinets with it.
They come scratched after Tours, 5 minutes with a brush leaves them as new.

EDIT: HiFi/Home speakers use foam/rubber surround because they are softer and allow for smaller bookshelf cabinets, but PA speakers use much stronger impregnated cloth.