They say nothing lasts forever, but I think we can stretch the lifespan of drivers through preventative maintenance.
Many of us live in regions that become humid this time of year. We dehumidify, but sometimes this isn’t enough. Running the HVAC continuous can also be costly in some countries.
Last year, I opened a set of speaker cabinets to discover the driver magnets were wet and covered in droplets. Reading online, water has no adverse affect on ceramic ferrite magnets, the type most commonly used in loudspeakers. This is due to it being made of iron oxide that no longer reacts. Alnico on the other hand can be ruined.
It seems as time passes, the coating on some drivers’ motor assemblies begins to peel and then a combination of rust and white corrosion forms where the metal parts meet the magnets. It remind me of galvanic action, but I’m no metallurgist.
What is your procedure to remove the rust and stop corrosion? Do you use sand paper, or a wire wheel on a rotary tool to get down to bare metal surfaces? Do you apply a light coating of 3-in-1 machine oil, a penetrative rust inhibitor, or is there another coating to prevent further corrosion? Does that have any long term effect on the magnet or glue?
Thanks in advance, guys ‘n gals.
Many of us live in regions that become humid this time of year. We dehumidify, but sometimes this isn’t enough. Running the HVAC continuous can also be costly in some countries.
Last year, I opened a set of speaker cabinets to discover the driver magnets were wet and covered in droplets. Reading online, water has no adverse affect on ceramic ferrite magnets, the type most commonly used in loudspeakers. This is due to it being made of iron oxide that no longer reacts. Alnico on the other hand can be ruined.
It seems as time passes, the coating on some drivers’ motor assemblies begins to peel and then a combination of rust and white corrosion forms where the metal parts meet the magnets. It remind me of galvanic action, but I’m no metallurgist.
What is your procedure to remove the rust and stop corrosion? Do you use sand paper, or a wire wheel on a rotary tool to get down to bare metal surfaces? Do you apply a light coating of 3-in-1 machine oil, a penetrative rust inhibitor, or is there another coating to prevent further corrosion? Does that have any long term effect on the magnet or glue?
Thanks in advance, guys ‘n gals.
Kouiky,
1) All of the above, though the wire wheel should be non-ferrous material to avoid more magnetic particulate being produced that will need to be removed from the magnetic gap. Emery sand paper works well.
2) 3-in-1 machine oil and similar are petrochemicals and evaporate relatively quickly, so have little long-term benefit.
The product CorrosionX actually disrupts rust and corrosion on the molecular level (displacing it from the metal surface and keeping it from spreading), and provides long-term protection against rust and corrosion on any metal surface.
It is especially useful in salt air environments that promote bi-metallic corrosion.
3) When CorrosionX initially came on the market back in the 1980's, it was demonstrated using an analog cathode ray tube TV set operating completely immersed in the fluid.
While I can't guarantee CorrosionX may not react with some types of glue, it has no adverse effect on magnetism.
I've used it on compression drivers that had previously had the voice coils "frozen" in place with corrosion with great success.
Art
Thank you so much for contributing, gentlemen.
My rust issue seems to be on the external surfaces of the driver motors, around the outside perimeters where the metal meets the magnet. Sand paper and a fibre wheel worked well to clean up the metal.
It doesn’t seem there is any problem in the magnetic gap, and that’s a good thing. These woofers don’t really come apart, or else I would have taken a look. Dynavox was pretty clever by allowing their drivers to be taken apart in sections, and I wish more companies would consider including that ability.
There are some areas where it’s hard to get at the rust, like one spot that looks to go between the magnet and metal components. I will get some CorrosionX.
My rust issue seems to be on the external surfaces of the driver motors, around the outside perimeters where the metal meets the magnet. Sand paper and a fibre wheel worked well to clean up the metal.
It doesn’t seem there is any problem in the magnetic gap, and that’s a good thing. These woofers don’t really come apart, or else I would have taken a look. Dynavox was pretty clever by allowing their drivers to be taken apart in sections, and I wish more companies would consider including that ability.
There are some areas where it’s hard to get at the rust, like one spot that looks to go between the magnet and metal components. I will get some CorrosionX.
