I want to remove the magnets from the flywheel that I will use to build my coil tester. I want to clean everything and paint all that needs to be painted. Is there anything that I should not do to clean the magnets that might damage or demagnetize them? I'm thinking about cleaning them with the wire wheel on my bench grinder. How would be the best way to mark them so I can be sure to put them back in their original position. Cleaning will remove any paint marks that I put on. Will light punch or file marks hurt them? Thanks
Cleaning would be the first thing I would do. If you don't have a pressure washer take the flywheel assembly to a car wash and clean them up.
Spray the assembly with a good rattle can degreaser avaliable at the auto supply houses.
After its cleaned up and dried use a marker pen to mark the magnet position as you remove the magnets to possibly be remagnitized if necessary.
Clean them up individually if they are rusted but how much extent is up to you.
Some clean the magnets and then use flat black or semi-gloss to paint them. How bright and shiny you want to make your coil tester is up to you.
For mine, built a box and marked the circle like the magnets were original on the flywheel by replicating the locations of the dowel pins, etc.
Washed each in lacquer thinner and tested with compass to determine polarity, and marked the N/S pairs with yellow welders ink pin, to be sure they went back on the flywheel correctly. Just left the magnet finish factory, no paint.
Each was re-magnetized with homemade charger of wire wrapped coils.
You really want to put "keepers" across your magnets until mounted.
I suggest you not mark them using a hammer as the shock will reduce the magnetism. You can find the polarity easily with a compass. For storage you can connect any two together so they attract.
I really would like for the coil tester to look nice. I might clean the up facing side before I remove them then mark them. I was thinking about numbering them so I can put each one back exactly where it is now. Overkill? Unnecessary? Silly?
I want support spools squeaky clean as well as all the other parts. I will replace the screws. I'm actually stressing because I know that I won't be able to get the mag coils clean as new.
Keepers really un-necessary if you are mounting right after recharge, the magnets will hold charge for a long time.
Numbered the box for each identified magnet, re-charged them, (be sure to charge them with the same + & - they were for best results). Painted the bolts and standoffs with alum. paint for bling..
For the coil ring, splurged and got a rebuilt ring.
Pretty much what I said Dan - "until mounted".
I take them off for cleaning with gasoline, lacquer thinner, rattle can carb cleaner, whatever. You can easily ID north and south poles with a compass. Give them a good charge. Mount them SS NN SS NN SS, etc. I agree with Tony about not hammering charged magnets, but you can whack each one against a vise or an anvil a few times to check for cracks BEFORE you charge them.