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From numerous posts, I see that a lot of people are still recommending using chemical stripping as the first step in restoring their aluminum. While this works, IMHO there's a better way and it will cut out many of the steps in the process compared to what's being recommended. If you don't have power tools (and preferably air tools), don't bother reading any further as this won't be much help to you. But for those of you who do, read on...
Chemical stripping is stinky/messy and may need multiple applications to get all the old coating off. And it does nothing to prep the metal for polishing, so you'll still have to deal with any oxidization, nicks, and scratches.
To do all the strippng and most of the pre-polish prep in one shot, use 2" 'surface conditioning discs' AKA 'Scotchbrite'. These can be found most anywhere in various brands, but buying bulk lowers the price considerably. I've found that these guys http://www.keenabrasives.com have very good prices and quality. Not advertising, just happy with their service/prices/products.
For restoring parts that were originally polished, I'll use 'blue' (fine) pads on an angle-head air die grinder (easily found for $30 or less). An electric drill will work also, just be a bit clumsy and slower. These will remove all coating and all but the worst of the oxidization/pitting, leaving a ready-to-buff finish in one step if you have a reasonably-sized buffing motor (say, over 1/2 hp and 3600 rpm). Smaller/slower motor? Do one more step with 'grey' (very fine) pads and reduce your buffing time by 1/3.
Got some pitting and/or deep scratches/nicks? If it's on a 'outside' surface, I'll remove/blend these with a 400 grit 5" aluminum oxide disc on an air sander; a 5" electric grinder will work just as well. If you have a 'wavy' surface, this will also smooth/flatten it nicely. Again, with a decent sized buffer you'll have a ready-to-buff surface. Can't get the 5" disc in there? Then switch to coarse 'maroon' discs to get rid of the problem, following with the finer discs. You can get these discs as small as 3/4" diameter, so there shouldn't be many areas you can't get to. These methods also work very well to strip/smooth die-cast parts that were never polished, such as handcontrols, brake parts, etc. Not removing the paint beforehand gives you a 'guide coat' so when the paint is gone, you know the part is ready. Doing rough sand-cast parts? Then start with some 320 grit 2" discs, switching to the pads after you get all the casting flaws gone.
For buffing, I'll do just two steps; start with a sewn cotton buff using tripoli compound, then finish with a loose buff and white rouge. This will give me a near-chrome finish. Results? Look here:
http://s777.photobucket.com/albums/y...Brakeparts.jpg
This all seems complicated, but it's not. I can restore most typical condition average-sized parts in under 2 hours, start to finish, so it can be a huge timesaver. Larger or 'complicated' parts will take longer, smaller less. Never-polished parts will take longer, depending on how much work is involved in the prep to get them smooth. And sure, there's a dollar outlay involved, but it's not that much more than using chemicals and sandpaper if you have air/power tools. And the pads are useful for other things too; stripping paint and rust (the pads work great for cleaning rusty brake rotors), cleaning gasket surfaces, and decarbonizing heads/pistons.
Try it, you'll like it!
'78E original owner
Chemical stripping is stinky/messy and may need multiple applications to get all the old coating off. And it does nothing to prep the metal for polishing, so you'll still have to deal with any oxidization, nicks, and scratches.
To do all the strippng and most of the pre-polish prep in one shot, use 2" 'surface conditioning discs' AKA 'Scotchbrite'. These can be found most anywhere in various brands, but buying bulk lowers the price considerably. I've found that these guys http://www.keenabrasives.com have very good prices and quality. Not advertising, just happy with their service/prices/products.
For restoring parts that were originally polished, I'll use 'blue' (fine) pads on an angle-head air die grinder (easily found for $30 or less). An electric drill will work also, just be a bit clumsy and slower. These will remove all coating and all but the worst of the oxidization/pitting, leaving a ready-to-buff finish in one step if you have a reasonably-sized buffing motor (say, over 1/2 hp and 3600 rpm). Smaller/slower motor? Do one more step with 'grey' (very fine) pads and reduce your buffing time by 1/3.
Got some pitting and/or deep scratches/nicks? If it's on a 'outside' surface, I'll remove/blend these with a 400 grit 5" aluminum oxide disc on an air sander; a 5" electric grinder will work just as well. If you have a 'wavy' surface, this will also smooth/flatten it nicely. Again, with a decent sized buffer you'll have a ready-to-buff surface. Can't get the 5" disc in there? Then switch to coarse 'maroon' discs to get rid of the problem, following with the finer discs. You can get these discs as small as 3/4" diameter, so there shouldn't be many areas you can't get to. These methods also work very well to strip/smooth die-cast parts that were never polished, such as handcontrols, brake parts, etc. Not removing the paint beforehand gives you a 'guide coat' so when the paint is gone, you know the part is ready. Doing rough sand-cast parts? Then start with some 320 grit 2" discs, switching to the pads after you get all the casting flaws gone.
For buffing, I'll do just two steps; start with a sewn cotton buff using tripoli compound, then finish with a loose buff and white rouge. This will give me a near-chrome finish. Results? Look here:
http://s777.photobucket.com/albums/y...Brakeparts.jpg
This all seems complicated, but it's not. I can restore most typical condition average-sized parts in under 2 hours, start to finish, so it can be a huge timesaver. Larger or 'complicated' parts will take longer, smaller less. Never-polished parts will take longer, depending on how much work is involved in the prep to get them smooth. And sure, there's a dollar outlay involved, but it's not that much more than using chemicals and sandpaper if you have air/power tools. And the pads are useful for other things too; stripping paint and rust (the pads work great for cleaning rusty brake rotors), cleaning gasket surfaces, and decarbonizing heads/pistons.
Try it, you'll like it!
'78E original owner
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