(ET) More on loose magnets

["Steven Naugler" <snaugler earthlink net>]

Sorry to respond rather late on the loose magnet issue, but we were on vacation without e mail.

 

So, more on the loose magnets.  I've epoxied magnets on two motors successfully.  One was a 3-1/2 inch diameter GE mower deck motor, the other was a SAAB convertible top hydraulic power pack motor, and on it the magnet was cracked into 4 pieces.  In neither case were the cases rusted.  Both have been in service for more than four years, so I believe the repairs are permanent.  I don't think you have much to lose by trying.

 

I used whatever epoxy I had that was not a fast cure.  First, I made sure that all surfaces were meticulously clean.  After the epoxy was hard for 24 hours I post cured for another 24 hours an top of one of those portable liquid filled electric heaters that look like a radiator, which was set on low.  I think that a post cure can be beneficial because some epoxies soften when they get hot the first time after their initial cure. 

 

I learned this from reading about composite homebuilt aircraft, and virtually all I have read states that a post cure of epoxy structures is mandatory in critical epoxy/fiberglass structures.  Is this an old aircraft homebuilder wive's tale?  I can't say, but I have had good luck with this technique when several local motor shops will not reglue under any circumstances.  I suspect that they cannot tolerate a failure rate of 5 to 10 %, where we GE tractor folks would be tickled with a success rate of 90 to 95 %.

 

 

--- Steve Naugler

--- snaugler earthlink net