Tannoy K3809 - hardened cloth surround issue - solved

yes indeed
i did neglect to mention that after applying the photoflow solution you apply kodak print flattener undiluted and viola!

to be clear it's 1 part photoflow to 8 parts water applied with a soft brush (in some cases with old crusty drivers at this point you may have to wipe away loosened crud and reapply) and finish with the undiluted print flattener
 
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Uhhhh OK You realise that Kodak Photo Flo is a passably pure SOAP solution. No more No less.
As far as comlpetely unintended useages: Many use it in their Race vehicles cooling systems as a surfactant Meaning it can result in a couple of degrees lower running temps

Not Bloody likely I'd be soaping MY tannoys 🙂
 
Bare
don't forget the second half of the solution the print flatener!
besides it's dirt/dust that settles into the weave of a surround and or spider that stiffens it and also aids wicking out moisture that should be there.

and like Zen Mod said they'll sound cleaner
 
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work 😀 tnx ZM
 

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Hi, guys

A couple points. First, Photo-Flo is a detergent not a soap. It works by dispersal(lowering surface tensions) not as a soap does, dissolving polar(waterbased) at one end of its molecule and non-polar(oilbased) at the other. The flattening solution's residue is mostly glycerin and it regulates moisture levels in paper, film, other hygroscopic materials.
Second, many different materials have been used as sealants for cloth surrounds, the most important thing is to classify the stuff they used. Water-based, oil-based, emulsion(kind of both). Right now I have a fairly easy job, as one of a pair of woofers has a healthy surround, while the other seems to have been more exposed to the elements and has 30 degrees or so really hard and the rest half bad. So I have something to compare to(74hz to 44hz). If the cleaned and retreated woofer acts better than the 'nice' one, I'll clean and treat that one to match. These are unknown Japanese from Criterion, nice cast frames from about 1970. Their cloth is impregnated with what acts like a natural/butyl mixture of rubber, so it's outside with mean solvents for me.
Bicycle tube patch glue, diluted, is a good replacement, although it lacks carbon black pigment. Tubeless tire rim sealer for cars is a good source for black stuff for rubber type sealers(there's a new waterbased version, you can thin it with alcohol).
 
Zen Mod,

I asked Simply Speakers about the Part number listed as a possible solution and here is their reply:

Hello, The MI-1291 is certainly used to treat cloth edges. Our material dries clear and a bit tacky. We've seen other "doping" materials that behave a bit differently than ours. Some seem to never fully dry for example. Sorry we are not familiar with what exactly was used on your Tannoy's so although our product will treat the edge it might not be the exact same sealer that was originally used.
 
Great info here. Thanks.

I have Tannoy LGM 12" and the cloth surrounds are stiff. Researching this it looks like some have used mineral oil to soften them (or grapeseed oil). Subsequent to application there is the trick of playing a 25hz tone for several hours (at moderate level) to futher loosen them up.

This discussion takes a different approach of removing the old doping entirely and re-applying.

Is there a benefit to one method (softening) over the other (removing & reapplying)?