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Polishing 101
07-11-2012, 04:18 PM
Post: #1
Polishing 101
Disclaimer: I hold no responsibility for your lack of elbow grease and determination when it comes to doing things right. If you don't like your results you only have yourself to blame.

Find your local auto body supply store and get the following items:

1. 120 grit
2. 240 grit
3. 400 grit
4. 600 grit
5. 800 grit
6. 1000 grit
7. 1500 grit

Now you can get any combination of the above mentioned papers but for the 400 and up make sure they are for metal and not wood or plastic.

Polishing compounds/products:
1. Tripoli burnishing compound
2. Rouge polishing compound
3. 2 Sisal buffing wheels (you figure out what ones you will need based on what mechanical polishing tool you will be using. EI: grinding wheel or drill)
4. Some sort of All metal polish (Meguires, Mothers, etc)
5. Terry cotton polishing cloths (old T-shirt, socks, whatever)
- This is the best and most complete kit you can get right now that I have found:
• If you are not taking the parts off the bike to do this, tape off anything you don't want to sand, scuff or damage. There will be a lot of dust and a lot of water in the later stages.
• Items with anodized finishes or brushed aluminum surfaces need to be stripped first of the outer coatings by either chemical or mechanical means. This is purely optional as the 120 grit paper will take off any of the coatings that will be on the parts; it will just take more time and more elbow grease.
120-240 Grit
• Start with the lowest grit sandpaper for the job at hand.
• If its the frame you want to polish, you can remove the outer coating via mechanical sanding, but I highly discourage the use of hand sanders after that. they WILL leave gouges in the metal regardless of the grit. Get through the rough parts with the orbital hand sander using a 240 (I don't recommend a 120 on the power sanders) and DO NOT press hard.
• If the item in question is a brushed aluminum finish on it and the easy-off oven cleaner you used didn't take the finish off of it, you are gonna have to bear down and use some plain old fashioned elbow grease, and sand away for a while. I like to go across the grain of the brushed surface so I know I have gotten all the scratches out from the finish.
• If you are doing parts that may already be somewhat polished you may be able to skip a few grades of sandpaper and just start with a wet grade paper (400-600). The only problem I have found with doing this is that some cast parts, like levers and shifters may have pitted blemishes or rough spots from the casting molds that were not completely sanded down. The higher grits of paper will not get these casting marks out and you will end up with funky looking lines or bumps on your polishing.
• Once you think you have gotten all the largest scratches and blemishes out, get another piece of that same grit and go over it again. I Can't Stress This Enough! Once you think you are done with that grit paper go over it again. Cuz I swear to you, you missed something, and you just cant see it until you get up into those really high grit papers. Once you do realize that you missed some scratches and you are in the middle of a 1000 wet sand, you gotta go all the way back down to about 400 and try and get it out. I have had parts where I thought I was almost done and missed a few lines on a brushed aluminum heel guard and I was forced to go back down to 240 to get them out. But hey. It's your finger tips.
• When you get done with the 120 and move to the 240, I like to go across the grain again. Some ppl will swear by the fact that this is a mortal SIN. That by doing this you only make deeper scratches that you have to sand out. From my experience, I find that I make less mistakes in sanding and I am able to make sure I get every little groove from the grit before and here's why: When you go cross grain, the lesser grit you are using causes the larger grit grooves to really show up. When you can really seeeee the grooves left by the previous grit you know EXACTLY when to stop sanding with the current grit. When the large cross groves are gone, you're done. Simple as that. If you go WITH the grain on the previous grit, you can end up leaving large grooves behind and eventually have to go back to larger grits and repeat you steps. You try it both ways and then decide for yourself.

400-600 grits
• With the 400 and 600 grits you CAN go wet sanding. Personally I don't think its worth it at this high of a grit. I have done it both ways and I have yet to see a difference in time or quality. it just makes a mess with all that water, longer.
Again, starting with the 400 grit I like to go cross grain from the previous 240. Some ppl will say you need to go to a 300 or a 360 grit in-between the 240 and 400, and maybe they are right. I have never done so and all my results seem to be just as good. If its a time saver.... you be the judge.
• With the metal sandpapers you may get a slight residue build up on the paper and the part itself. You are going to have to change papers frequently or keep cleaning the ones you are using. Just don't let it build up too much.
At this point your sanding times should start to decrease incrementally. The higher you go the less time it takes for the next grit.
• Oh yeah, by this point, if you fingertips. hands, or forearms don't hurt, you haven't sanded it enough and you will most likely have to go back and fix some stuff you missed. But then again you may not be as anal retentive as I am and not really care if your part has a small blemish or two...
800-1000 grits
• This is where it gets messy. Wet sanding.
This is probably the most dramatic change in the parts quality level you will see through out the whole process. Once you start wet sanding the piece the luster should be dull but noticeable. With the 800 grit, sand across the previous grit under running water or frequently dunk the part in a bucket, to remove the fine dust. the object here is to not let the particles you remove from the metal build up on the surface of the part or the surface of the sandpaper. This can lead to streaking and uneven wear on the sandpaper itself. When I was polishing my rims, I would frequently get little dust burs embedded into the sand paper itself from the friction of the metal against the paper. Note: If you are completely hand sanding with no forms of mechanical help, you really do not have to worry about this, but you do still have to get rid of that build up. Use plenty of clean water.
• Now on to the 1000 grit sandpaper; Cross grain sanding 2 Win! More Water James! You hands should be well pruned at this point as well. With the 1000 grit you should almost get a nice shing to the part. Not a true bling bling, but not a dull luster either. It should look like a really foggy mirror.
1500+ grit
• with 1500 grit you will really get a nice shing to your bling bling. You should have no noticeable scratches, the shine should look almost dull with streaks, but you should almost be able to see a very blurry image of the world around you in your part. You CAN go up to 2000 grit but its kind of a waste, as the polishing with the Tripoli and rouge will take care of that for you.
Note: You will NOT be able to get a mirror finish by hand. Can't do it. I tired.
Let me rephrase that. You CAN'T do it in any decent amount of time that any gawd fearing, hard working, red blooded American that holds a real job, and only polishes in his/her spare time, by hand. Make sense? No? Good.
Get a Bench mount grinding wheel.
They're like $45-90 at Home Depot (if you don't have one already) or a really good variable speed drill that is not battery powered. Reason why I say not portable/battery powered is that you really don't want to keep changing batteries in this process. that would just be lame, but suit yourself.
This is my first and foremost, method of choice. Having taken jewelry smithing in high school, I am well accustomed to metal polishing and the techniques.
• Get two sisal wheels of differing strengths that are the right size for your bench grinder, usually 5-6 inch wheels I think. One medium density and one hard density. (actually two mediums will do fine) The process for using a hand drill is the same. Two wheel or buttons, one for each compound.
• Use one wheel for the Tripoli and one wheel for the rouge. Start off with the Tripoli on the hard sisal wheel and burnish the part to get a nice luster out of it.
• Once you can really start to see your self in the metal, move over to the other wheel with the Rouge. This will REALLY hit that bling bling mirror look. If it doesn't then you didn't sand it well enough.
• Now that you have really brought out that SHWING from the metal, finish it off with a bit of All metal polish, just like you were waxing the paint on your bike or car. Rub the metal polish on with a clean soft cotton terry cloth (T-shirt or sock) and wait for the polish to turn black. What its doing is pulling all the impurities out of the metal and giving it even more luster and shine. After the polish has completely oxidized, buff it off with a different clean terry cloth and go shave in the glorious reflection that is your shiny new metal part!
1. Buy supplies
2. sand
3. sand
4. and more sanding
5. Polish
6. buff
7. Shave
8. Put back on bike.

Now, I am one of the most impatient, anal retentive, bling bling lovin MoFo's out there when it comes to his own shizzle. I don't trust ANYONE working on my bike for the most part and if I can do it myself I will. As far as polishing goes, I am more then happy to spend the time and elbow grease to do it myself, rather then let some one that has zero interest in the quality of the product he's working on, other then the fact that its giving him money. These are very simple and relatively easy things to do. they just take time, patience and determination to make them look good. You decide how you want it to look. If kinda hazy is okay with you - fine. You be the judge of what looks good to you.
If you take your time and put in the effort I guarantee you will get the best results possible.
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