This started off in the powder coating thread but since it is important info if you want to polish an alternator it is worthy of it's own thread.
I did not take pics of the disassembly because that is pretty basic; remove the pulley and NOTE the spacer bushing when reassembling. Do not remove the 3 screws closest to the shaft until after you pull the front cover with the armature still attached to it.
The three screws farthest from the shaft come out and then you can pry and tap around to split the housings.

There are screws that hold the brush assembly in the back housing. Remove the three screws that hold the armature in and the from and rear cover should be free of any linger parts bolted on at this point.
You will want to paint the exterior of the coil.

At this point you can grind the casting ridges ( I know I didn't ) and bead blast for powder coat as I did or polish.

When you go to assemble the alternator put the armature shaft through the from cover and put the three screws into the retainer. The retainer kind of roams around freely back there as you will find out when you try to start the screws
The other thing to watch for is that the brushes have to be pinned back into their holders with a paperclip or tig wire or whatever you have to do the trick.
This allows the armature to pass the brushes without breaking them.
These brushes are horribly worn but since I am not using the alternator soon I am just throwing it back together instead of making a parts run. I just wanted to test this particular powder coat.
Once you have the assembly together be sure to pull the wire out the back and you will hear the click of the brushes popping into place.

That should do it.

 

Looks great, thanks for the tip. Any advice on polishing the alternator by it self?
I've got a variable speed rotary tool and some sand paper rolls, what else would recommend?

 

Polishing is not fun if you are doing it wrong or right. I try to avoid it unless it is a spinning part on a lathe.
But for those with more patience for it this is a great source of knowledge as well as supplies.
This is one of the best reads on the subject you will find for free

http://www.caswellplating.com/buffs/Buffbook.PDF

 

scalliwag....when an alternator goes bad.....what exactly goes bad in it...and when it is rebuilt...what is replaced?

 

The stator, rotor/armature, rectifier, diode, voltage regulator, brushes, brush holder, and bearings are all subject to failure.
I have personally had more regulators and diodes but a person that works at a rebuild shop may differ with me on that and I would not be able to argue with someone that has done 100's of them.
Bearings usually only fail when some dumbass puts too much belt tension against it. The bearing absorb the load and overloads them.

 

For what it's worth the brushes are $3.69 a set, rectifier- $35.99, and regulator is $31.99 at my local auto parts. A rebuilt is $93.99. This is priced for an '86 because that is what the one I coated is. Others *should* be real close in price.
I would want to shop the price for everything except the brushes because the other parts are pretty high.
You can get a rebuild kit with regulator, bearings, brushes for most GM alternators for about $30 last time I checked.
But isn't that the way it is with these

 

another question....how do u know which part is bad?....the brushes the regulator or the rectifier?

 

Like I said if you want more details on diagnosing alternator components do a Google search and get a good multimeter. A little more to that than for me to type a three page response.