Kef Reference Tweeters-Ferrofluid Replacement

A bit of a sideways question: does the ferrofluid also dry out if the tweeter is stored in a plastic bag? In other words, is it possible to buy replacement tweeters and store them for 20-25 years without the ferrofluid drying out (which would defeat the purpose of buying replacement tweeters)?

Don, good question!  I'm not an expert on ferrofluid, but I would believe yes, it can dry out just sealed in a plastic bag.  The ferrofluid comes hermetically sealed in a small pouch, similar to what you get catchup and mustard in.  The pouch needs to be cut open to get the fluid out.  If you were to buy new tweeters, I would still take the half hour to clean out the old fluid and install fresh fluid.  Best to not be penny wise and pound foolish!  There may be additive packs of chemicals in the ferrofluid we are not aware of that can off gas into the atmosphere, including a plastic bag......Lou

My speakers are Reference Series Model Ones. I bought them from a consignment shop in pristine condition knowing they might need the ferrofluid replaced.

I was elated to hear they they sounded great when I hooked them up. It didn’t take long before the left speaker lost definition. I figured no big deal, I will replace the fluid. All went as planned except there was no sound whatsoever when I went to test the “repaired” tweeter. After checking impedance (which I should have done before the repair), I got nothing. I do not know if I damaged the fine wires connecting the voice coil while cleaning it or if they blew prior to the repair.

As of now, there is no continuity between the leads of the tweeter. Also after rebuilding the tweeters, the VC/dome has completely separated from the speaker and floats free, levitated by the ferrofluid.

I purchased replacement domes off eBay and will now need to learn how to install them. Any tips on glue type to secure the diaphragms?

 Tiny touchy stuff, those tweeter wires. Broke one once, and was able to make just enough slack for solder. It was a miracle that it worked the first time.

 Ferrofluid is added to the voice coil gap in order to damp the tweeter cone itself, not to lubricate it. And yes, it dries up whether the tweeter is used or not. Same as electrolytic capacitors that are stored for years are not quite the same as they were coming off the line.

Skid, I'm not sure about the glue.  Ask the folk's your buying the new pieces from....and good luck!  Let us know how it works out.