Is this speaker ok to use?

[greengriff]

I don't want to stick it in a cab and put an amp through it at volume until I get an opinion. You can see a part of a thin layer on the surface of the cone has lifted off in one place and is starting to lift off in another.

 

[pdf64]

I'd stabilise the affected area with a coat of suitable doping and enjoy it. No reason not to use it in the meantime.

 

[greengriff]

Thanks! What would be suitable doping? Also would you peel away the loose material that's not yet torn off? Or stick it back down?

 

[pdf64]

Thanks! What would be suitable doping?

I'd ask at a couple of recone parts suppliers. I think that brushing on a thinned down rubber solution type of glue should do it. What region of the world are you in?

Also would you peel away the loose material that's not yet torn off? Or stick it back down?

That's something of a judgement call really, depending on how thick the loose section is compared to the remaining cone. If the loose bit is thinner, then probably remove it, eg with a scalpel. If it's similar or thicker, then probably best to stick it down.

 

[greengriff]

Thanks again. I'm in the UK.

 

[greengriff]

Any thoughts on liquid latex as a dope? It's cheap enough and stays flexible.

 

[pdf64]

@J M Fahey

 

[greengriff]

Something like this maybe?:
Kryolan Vulcanised Clear Liquid Latex (redcarpetfx.com)

 

[billyguitar]

I use black automotive RTV gasket stuff in a squeeze tube. It's black and always does a good job, stays flexible. Cheap and available at any auto parts store. I've had the same tube for at least 25 years and it still works great.

 

[greengriff]

Is that the stuff that is basically silicone rubber? Or something else?

 

[greengriff]

Something like this? Granville Instant Gasket Clear Sealant Flexible Jointing Compound 40g 5020618004493 | eBay

 

[pdf64]

What would be suitable doping?

Thinking about it, I seem to remember @J M Fahey mentioning that thinned down PVA was used by manufacturers for the edge treatment on the cone surround.

 

[greengriff]

As in the kids' glue? Do you recall what it was thinned down with?

 

[pdf64]

PVA is a water based glue, used extensively in building construction to strengthen and stabilise porous materials.
Yeah, its water base and non-hazardous / toxic nature makes it suitable for kids to use.

 

[greengriff]

So maybe it was thinned down with more water?

 

[slider313]

I use black liquid electrical tape for doping.

View media item 226101

 

[pdf64]

So maybe it was thinned down with more water?

Yes, to help get the PVA absorbed into the paper. Maybe 1:1 or 2:1 ratio of water to PVA. But it may be best to wait for a speaker builder to chip in @Scumback Speakers @TAWeber
My previous suggestion of a rubber solution type glue may not have been good, as it might set harder over time, rather than remain flexible.

 

[greengriff]

I would have assumed that one would want it to remain flexible?

 

[greengriff]

I use black liquid electrical tape for doping.

Something like this? Insulating Tape - Liquid Electrical Tape 118 ml - Red: Amazon.co.uk: DIY & Tools

 

[slider313]

Something like this? Insulating Tape - Liquid Electrical Tape 118 ml - Red: Amazon.co.uk: DIY & Tools

Yes. That happens to be red in color but I'm sure it comes in black.