Living dangerously in the Neo gap

squarewave

Member
2009-05-20 3:20 pm
I decided to live dangerously and disassemble my 1990's Seas tweeters ( 25TFFN/X), from the Seas 170mm coax ( P17REX )


The ferrofluid had gummed up and was preventing voice coil movement.

How can I easily clean the, less then 1mm, gap of this very powerful neodymium magnetic, from all those tiny magentic metal filings?

:scratch2:
 

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BradH

Member
2019-07-13 10:35 pm
I'm just guessing for fun, but would it make any sense to put a few drops of alcohol solvent in there, drain and repeat?

Then even if the metal bits stay inside, you've cleaned out the gunk and can add back whatever solvent was in there in the first place? I'm guessing a mineral oil.

I usually scoff at these kind of replies because there's a right and a wrong way to do things and if you don't know then it's probably better not to say anything. So sorry for that.
 
Ferrofluid is iron oxide particles (think magnetic recording tape) suspended in kerosene oil with a binding agent. I can't quite visualise how this polepiece is constructed, but I have done this job on a SEAS 19TAF/G tweeter:

599662d1487267698-restoring-monitor-audio-r300-bookshelf-speakers-seas-19-taf-jpg


660070d1517514440-recap-20-monitor-audio-703-pmcs-ferrofluid-jpg


Sonitus Audio Ferro Fluid (ferrofluid) 0.5ml from Sonitus Audio PS4.99 IN STOCK (7 Mar 2020)

Because the magnet is metal, I used a lubricant spray like our UK WD40 to loosen everything up, and a piece of blotting paper to soak up the residue. I then thoroughly dried everything out before applying 0.1mL of new ferrofluid. I don't think the exact quantity or thickness matters much.

I think parts express sell it in North America.

Not damaging the voicecoil was the delicate issue. I'd try and keep any spray away from delicate parts. I expect SEAS would reply to an email if you have any queries here. Norwegians all speak English. :D