Centering cone during surround replacement

[pinkmouse]

Originally posted by mrfeedback

Use a small brush or cotton bud, and keep moist the dome glue joint with tolulene, until the glue turns to gel and the dome lifts off easily - up to half an hour depending on the glue.

Good advice, Eric

The time I tried to track down toluene for the above use I could only get it in 50 gallon drums- a tad more than I needed, and I believe it is now on the list of controlled chemicals in the UK due to its potential misuses...

Reconing/resurrounding speakers is often looked on as a bit of a black art, but if you are careful, methodical and patient, it is actually very straightforward. So, if you can get the bits, then give it a go one day

[mrfeedback]

Locally, if you can convince the guy at the local hardware shop that you are not a crazed glue sniffer, you can buy a 500mL bottle of Tolulene for AUS$6.00 or so.
I forgot to add - keep well upwind of the fumes, and put the thing outside while the fumes dissipate (thats partly why I said "a day or so" twice).

Eric.

BTW - Tolulene is a good solvent for thinning Silicone.

[ashok]

Eric,
How do you fix a Dynaudio surround ? I am about to fix a 12 inch Dynaudio driver with a rubber surround. The original foam surround collapsed rather fast ( about 2 years old). I have a plan but would like to know how you do it.
What glue would you use on the Dynaudio , to glue a rubber surround. don't give brand names but generic type. We don't get too many types here. I was contemplating on using a rubber based glue.
We also get PVA based glues ( used for wood generally ) and two tube expoxies .
Thanks.

For rubber based glues Xylene is a good solvent. It also seems to be good for thinning down two tube expoxy glues ( before setting).

Cheers.

[mrfeedback]

On the Dynaudio drivers with the one piece PP cone (the VC former is glued to the backside of the cone), if you take a very close look you will see four small pinholes.
These are the result of inserting four wires down into the VC gap so as to center/align the VC.
One of the guys at the Dynaudio factory told me that is how they do it when giving me a factory tour.
I think a good quality yellow contact adhesive would be suitable to glue the new surround.
Another alternative (probably better) is to use a particular latex glue (white when liquid, dries clear and remains slightly tacky).
this type of glue is used on a lot of drivers, and comes with the Jaycar surround kits, but I do not know where else to get it.
Anybody know where ?, or its correct name ?.

Hope this helps,
Eric.

[Kanga]

Hi Cyclotron - I'm in Eltham, where the greenies and ferals are supposed to hang out in mud brick houses. Nice part of the world, but getting very cold at night here (-2 C last night).

Thanks for all your suggestions. Where were you all a couple of months ago when I posted the original question...

Hopefully next person who wants to do the same can benefit.

I checked out the rubber Jaycar surrounds and they looked OK, but seemed very "limp", so I wasn't sure if there was going to be an effect on compliance of the driver. For an extra $20 I got expert help and hopefully a perfect replacement.

Mick

[Thunau]

Originally posted by mrfeedback
On the Dynaudio drivers with the one piece PP cone (the VC former is glued to the backside of the cone), if you take a very close look you will see four small pinholes.
These are the result of inserting four wires down into the VC gap so as to center/align the VC.
One of the guys at the Dynaudio factory told me that is how they do it when giving me a factory tour.
I think a good quality yellow contact adhesive would be suitable to glue the new surround.
Another alternative (probably better) is to use a particular latex glue (white when liquid, dries clear and remains slightly tacky).
this type of glue is used on a lot of drivers, and comes with the Jaycar surround kits, but I do not know where else to get it.
Anybody know where ?, or its correct name ?.

Hope this helps,
Eric.

That's nice to know. I have a set of 24W100 that will need work one day. Thanks.
I refoamed a pair of old 30W54's without removing the center dust cup once. It just wouldn't come off with regular solvent that I had (acetone based). So, I used a different trick. I played a 3000Hz tone through it at maybe half a Watt while glueing the surround to the frame. The electromagnetic force centers the voice coil perfectly.
Another trick with Dynaudio I had to come up with was to attach the surround to the cone from the back side before glueing it to the frame. I used a 10" plastic kitchen bowl to hold the edge of the surround against the frame. It's a perfect fit. The bowl was sitting on the table and the driver was sitting on it with the magnet facing up. The edge of the bowl was holding the flat part of the surround perfectly in place. I also used the bowl trick after glueing the surround to the frame. I let it rest on the bowl until the glue dried. It worked out very good.

[JOE DIRT®]

Good tip Jan!!

[capslock]

A heat gun or a hair drier is dangerous: many spiders will permanently sag even if they only receive some stray air, e.g. when you blow on the cone to remove the dust cap.

Toluene? This stuff is highly cancerogenic! Aren't there any other solvents like Acetone that work on the latex/dispersion glue that is used so often?

Regards,

Eric

[Nappylady]

cancerogenic--I like this word. It is now part of my vocabulary.

(/hijack)

[pinkmouse]

Originally posted by capslock
A heat gun or a hair drier is dangerous: many spiders will permanently sag even if they only receive some stray air, e.g. when you blow on the cone to remove the dust cap.

I have never had that problem, but then again, as I said, I am careful

I also use a heatgun with a temperature control, not blasting at full. I should probably have mentioned that earlier