Here is the best magnet bonding epoxy out there that I know of: Hysol EA9394 177 deg C rated capability based on maintaining 1Ksi Shear Strength.
NASA reference for Hysol EA9394 use bonding magnets in space flight generators (Page 264, marked 252-3 in report) http://www.scribd.com/doc/40109738/NASA ... ual-Report
Data sheet (with loads of good info): http://www.mtpinc-exporter.com/chemical ... 209394.pdf
Independent Sandia test report: http://prod.sandia.gov/techlib/access-c ... 950229.pdf
Where to buy it for $16 bucks through KR Anderson: http://www.kranderson.com/shop/Henkel-L ... 0ML-SEMPAK
This stuff is amazing. It has been tested in JP4 and hydraulic oil and held up fine per the data sheet. The data sheet also shows 600psi shear strength up to 400 degF!!!
A hint that makes the bond even stronger (applicable to all epoxies): Be very careful mixing to have as little air entrained as possible. Entrained air makes it weaker, but not to a failure level. I am talking about getting the last 15% out of this material with respect to bond strength. Also note the cure kinetics in the first NASA article and the data sheet. This material likes a higher than room temperature cure after one day at room temperature. Like 150 deg F for an hour or so after a day at room temperature
PS:If anyone is using epoxy in a production environment, just buy the THINKY mixer that meets your specifications and that you can afford. These centrifugal, planetary mixers (some with vacuum capability) are just the finest for preparing epoxies and epoxy compounds. It doesn't get any better!
A few hints from Fechter from the thread where I discussed this epoxy:
"Also make sure the surfaces are clean and have no traces of oil. I think when they manufacture the steel parts they are coated with oil and they don't always do a good job of getting all the oil off.
After mixing epoxy, a good way to get the air out is to pull a vacuum on the mixuture. I like to load the mixed epoxy into a large syringe, then push as much air out as possible, block off the tip and pull the plunger back. This expands all the air bubbles and allows them to float to the surface. The syringe makes it handy for applying the epoxy afterwards.
You can get some flavors of the Hysol stuff from McMaster-Carr."