Ferrofluid, anyone ever change it?

[Ratamahatta 437]

I have a few speakers that are past the 20 year mark and was wondering about the ferrofluid in the tweeter. I know the stuff was designed to last 20-25 years but sure there are exceptions in that estimate. Surely it just does not go bad if its not used at all?  I can buy new tweeters for some of my speakers but they are probably from the same 20+ year old stock mine came from.  I am going to imagine it goes bad from abuse more than anything. 

  Has anyone here replaced the fluid in their tweeters? if so what was the results? I have taken apart other 20+ year old tweeters to find an abundant amount of what appeared to be normal viscosity ferrofluid.  But have also read how some got so dried up the tweeter would not even function. 

  Thoughts?    

[4krow 6,572]

   Seems that I have heard about this fluid having a certain lifespan. If there is a way to change it out, it makes sense to do so if the fluid is at the end of it's useable life. I would expect that drying out would be from age or overheating or both.

[danowood 2,167]

No problem, just run them down to Jiffy Lube. 

[Nahash5150 10,681]

[compwaco 1,129]

The problem with replacing the fluid is there is no “one size fits all” solution. The fluid comes in many different viscosities and affects the damping of the voice coil. Unless you can purchase original fluid from the manufacturer (you couldn’t back in the early 1980’s) it will be very difficult to match up one that doesn’t change the sound of the tweeter.

[Ratamahatta 437]

The problem with replacing the fluid is there is no “one size fits all” solution. The fluid comes in many different viscosities and affects the damping of the voice coil. Unless you can purchase original fluid from the manufacturer (you couldn’t back in the early 1980’s) it will be very difficult to match up one that doesn’t change the sound of the tweeter.

 

But certainly putting some stuff from Parts Express is better than dried up or nothing at all.  

[danowood 2,167]

interesting video, wonder if a dental pick with a low setting and the alcohol solution would be a quicker way to clean it.

[Ratamahatta 437]

interesting video, wonder if a dental pick with a low setting and the alcohol solution would be a quicker way to clean it.

 

Or using an air compressor.  

[Nahash5150 10,681]

Yeah I wouldn't call his procedure orthodox, but it seems fine.

 

Personally, I would have used toothpicks and a printer cleaning kit like THIS. 

 

The cleaning card is alcohol saturated rigid felt and would have worked perfectly to clean out the magnet. 

[Ratamahatta 437]

OK I decided to just crack one open and have a look. Still fluid in them but you can definitely tell where it has leaked out.  I will probably just get some new and replace it in both and not have to worry about it for 20 more years. 

[Nahash5150 10,681]

lol 

 

Be careful and good luck! That looks like a lot of fun.

[Ratamahatta 437]

 

 

lol 

 

Be careful and good luck! That looks like a lot of fun.

 

Thanks I just ordered some new fluid from PE. I checked the fluid in my Sony ES SS M7's and it looks fine. no leaking, staining or anything out of the ordinary besides the voice coil itself did not appear to have any fluid on it. I might add a bit to those as well. Seems to me it would be useless if the voice coil was not in it at all.