Epoxy the magnets - End of story

[Dave B]

Let's get past it. Polyester used as an adhesive for magnets had problems. Cheap adhesives or poor preperation of the surface will have problems. As the doers out there will tell you, clean and prepare the surface properly and use a high quality adhesive such as an epoxy to secure your magnets, finished. No need to completely pour around the magnets flush  to the surface either, I think this was originally done to help "hold" the magnets in with polyester because they were not "glued" to the surface and of course it looked neat. People have been going on and on (mostly those who have not built an alternator) with their suggestions for fixing a non-existent problem. Prepare, clean and glue the entire magnet surface to the rotor with a thin layer of quality epoxy. Done.     Dave B.

[harrie]

Well I agree with using a good epoxy, but not your idea of the only way!!!!. I think there is always room for improvement, and think its great that some here keep trying.

[inode buddha]

Well, I can second that a bit, but its not about alternators. Years ago, my employer tasked me with building and potting some electrode holders for an arc furnace. They used soft 1/2 inch copper tubes in a coil, potted with "Devcon" brand epoxy and a heat-conducting ceramic filler. The Devcon cost about 200 bucks a quart, and the electrode holders sustained thousands of amperes for months. If I was going to build an alt right now, that is the material I would use. It might be easier and cheaper to find West system epoxy and experiment a bit.

[Dave B]

Never said it was the only way and I also give credit to those who have to try different ways because they keep losing their magnets. Dave B.

[wooferhound]

I use epoxy for anything that needs to be last a long time. I use the large tubes of it that you can find in Lowes or Home Depot. The longer it takes to setup, the stronger it is. I use the stuff that sets up in 90 minutes. For magnets, use the stuff that will stick to metal. The JB Weld stuff is magnetic and will crawl all over your magnets.

For my rotors I used Lots of Epoxy and Chopsticks for filler and strength.

[ghurd]

People should remember "5 Minute" epoxy is NOT Waterproof, only water resistant.

High humidity seems to weaken it. Actual water will make it fail.

Slow Cure epoxy IS waterproof.  And stronger too.

G-

[luckeydog]

I was going to use JB weld but i did not know it is magnetic. thanks you may have saved me some grief.