My exposure to magnetic seals is for rotational feed throughs for high vacuum systems. You don't get the iron filings ingested into the engine, if properly designed.

here are some links for those interested.

http://www.liquidsresearch.com/products/magnet_applics.asp

http://www.a-f-s.com/news/industrialphysicist.html

http://www.ferrotec.com.sg/category.asp?catid=9

Bill Schertz
KIS Cruiser # 4045


>
> > I don't think ingesting iron filings is the way to go, and I don't think
> magnets
> > will prevent ingestion.  I further don't think any of us can develop a
> reliable
> > ... SNIP