<VV> Super magnets attached to oil filter

[Stephen Upham]

Someone on vv told me that attaching super magnets to the body of the  
oil filter would not have the intended effect of trapping and  
attaching to the side of the filter any metal debris  suspended in the  
oil.  It didn't make sense to me, but not having a background in  
physics or mechanics, I just figured that there was some other  
physical property at play because I knew for a fact that magnets  
attract though both magnetic (ferrous materials) as well as non- 
ferrous materials.  I also knew that there was a ratio between the  
power of the magnet and the thickness of the material though which it  
would be able to attract.
So, the only variable that I had not experimented with was a  
suspension of metal filings in motor oil. I decided to use an object  
that closely resembles the material that an oil filter is made of and  
the approximate thickness; a soup can.  I then created some metal  
filings using a small metal rod and a file.  I poured new motor oil  
into the bottom 1/8 of the can.  I then added the metal filings and  
stirred them in order to dissipate them though the oil.  Of course,  
most of the heavier ones sank to the bottom, but some of course  
remained suspended.  I then placed a super magnet on the side of the  
can.  I re-stirred the mixture imitating what would happen when oil is  
circulating though a filter.  When I poured the oil out, there was a  
neat circle of metal filings attached to the side of the can in the  
shape of the magnet.
In my opinion, magnets do attract and hold metal filings suspended in  
oil when attached to the outside of a ferrous material; i.e., an oil  
filter canister. That said, I would suggest that attaching five super  
magnets to the bottom (circular end) of the oil filter is an added  
layer of insurance against engine damage.

Stephen