# Speaker doping; what products are you using?



## nbs2005 (Mar 21, 2018)

Hi all,

I was going to sell my 15 inch Chicago and had found a buyer. When I pulled it out of the cab however I noticed this:










Looks like abrasions to the outer edge of the cone in the first couple of centimeters. They do not appear to go through the cone. I let the buyer know immediately and he decided to pass.

My next search was around repair and/or doping this area of the speaker to stabilize it. There is of course specific speaker dope, though that seems hard to come by as of late. Folks also talked about using a water latex mixture commonly used for waterproofing.

Has anyone done this type of repair? If so, what did you use to dope the speaker? I'm intrigued by this; from what I've read doping will make a speaker warmer which just might be the right thing for this speaker and compel me to keep it.

Thanks for your feedback.


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## greco (Jul 15, 2007)

Following this very interesting (and unique...IIRC) thread.


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## nbs2005 (Mar 21, 2018)

greco said:


> Following this very interesting (and unique...IIRC) thread.


I'm glad you appreciate my 'odd' questions Dave. We'll see what comes up.


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## jbealsmusic (Feb 12, 2014)

Personally, I would use rubber cement, liquid rubber, or a speaker-specific repair adhesive on those abrasions before doping the speaker. It might not be necessary because the abrasions look small enough. But, the "dope" really needs to be applied evenly across the surface to be most effective. So, I'd do it just to be on the safe side.

Pro "dope" is always called "proprietary" by speaker manufacturers, as if they have some magic solution. But, it's typically some version of an industrial water based silicone or liquid latex. Technically, real speaker dope NEVER dries and is always tacky. It just collects enough dust and particulates from the air that it can appear to dry over time. You can buy similar stuff at hardware stores that are sold as roof sealers, carpet edge sealers, etc.

For an easier DIY "doping" solution, a mixture of 10 parts Weldbond (or some other quality PVA glue) and 1 part water is great (AKA: PVA90; 90% strength PVA). Some speaker service stores that sell "speaker dope" actually sell a similar mixture to this. It is very flowable, dries clear (satin-like finish), stays somewhat flexible, and won't attack/damage foam or impact other adhesives used on the speaker. Apply using a brush and lazy susan for easy application. Or, a brush and just turning the speaker on a soft surface like in this video (starting at 37:40):


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## nbs2005 (Mar 21, 2018)

@jbealsmusic Thank you for the great answer.


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## tomee2 (Feb 27, 2017)

Out there, on the web, somewhere...is a guy describing how he restored vintage Altec and Tannoy speakers with the tacky goopy edge treatment described. He got those sticky glue mouse traps, used solvent to collect the glue and then applied it to the cones edges. I think the never-dries stuff jbealsmisic alluded to is what is needed, but finding a source might not be easy.

I would also look for a cheap or free paper edge speaker, then try something out on that first.


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## epis (Feb 25, 2012)

These two work well.


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## jbealsmusic (Feb 12, 2014)

epis said:


> These two work well.
> View attachment 407331


Those look good. I should try them some time.


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## Mark Brown (Jan 4, 2022)

I use carpet latex, mostly because I have it on hand. Paper cone tears get nail polish, rim gets latex.


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