Metal Polishing

[Jeff]

I just modified an old tapered body bench grinder to use for metal polishing. I picked up some buff wheels and abrasive sticks at Home Depot. So far.... the setup is working flawlessly. If I can find another cheap grinder similar to this one.... I will most likely set up another so I don't have to change wheels. The motor housing has a nice taper on the ends to give more room to work. That would also give me a 4th end to try a flex shaft for working on larger pieces.

Now that I've gotten bit by the shining bug..... I was wondering if anyone else has found polishing metal to be a relaxing past time? I spent several hours this evening working on a few parts and when I was done..... other than my arms being a little tired.... I felt refreshed. LOL I can't wait to see the parts in the sunlight tomorrow.

[nashville_bill]

I find polishing parts to be very rewarding also. I bought this unit on sale for $69 and it has lots of power:

http://www.harborfreight.com/cpi/cta...emnumber=45901

I picked up several cotton wheels at: http://www.caswellplating.com/buffs/...c831b6a4164a01

[Shuriken]

I want to polish my bike. I've hand polished some of the parts. I did the forks and the two engine side covers. What a world of difference it makes to get all the gunk off the aluminum. I want to do the entire engine. Some parts are more stubborn than others.

I had an idea of going out to the local washer/dryer boneyard and yanking a 1/2hp capacitor start motor off of one of those beasts. I could then mount the appropriate wheel and get some compound.

I wonder how much it would cost to have someone sandblast the frame and motor for me... ??

Ben

[beechfront]

I started with the frame - it cost me just over $200 to have it sandblasted / powder coated. I am looking for a good way to shine up my aluminum which I've been trying to do by hand with not much luck.

[Jeff]

Hopefully this winter I'll be able to strip mine down to the frame and do it right.

As far as the aluminum parts.... using hand polishing materials such as Mother's or Simichrome do little more than remove surface oxidation and fill in the pores of the metal to improve its relective appearance. If the aluminum is severely oxidized, stained or pitted.... you have to get a bit more agressive. You can wetsand the parts using graduated grits to take care of these sort of problems but it is very time consuming and takes a considerable amount of elbow grease. Power buffing is quite easy and yields excellent results. The wheels and buffing compounds are only a couple dollars each.

Using a decent bench grinder or other sort of mountable motor, several buffing wheels starting with a spiral sewn cotton or cotton/sisal blend for the initial cutting of the surface to remove scratches and pits, on to a medium cotton single sewn wheel to "color" and finally to a loose cotton or even softer flannel wheel for a mirrorlike finish. If the part is dinged up.... you can wetsand with a sanding block to smooth it out. It is faster that way since a buff will remove material from inside the ding as well as on the surface.

Severely pitted parts you should start with an emory compound on a hard cutting wheel. If the surface is only stained or lightly pitted.... you can begin with a tripoli compound.

Setting the motor to spin the wheel away from you at the top is the safest and easiest method. That way if you should catch a part and fling it.... it flys away from you.

Using the hard wheel and heavier abrasives.... move the part across the wheel toward you, against the rotation to "cut" the surface getting the maximum abrasive action.

Once the surface is smoothed of all irregularities.... move to a medium sewn wheel and white rouge. For the most part in this step you will move the part away from you on the wheel, with the rotation. This is called "coloring" and is less aggressive on removing material. Its purpose is removing fine scratching and getting an even appearance in sheen.

Finally move to the soft wheel and red jewellers rouge. Use the same "coloring" motion as before to polish the surface to a mirror like shine.

Since most abrasives used are carried in a heavy wax or grease (similar to a grease pencil), there may be a greasy or waxy residue that will need to be cleaned using a good detergent and a very soft cloth. The part will be VERY easily scratched at this time so be careful. If you use the more expensive non greasy abrasives for the final stage you can pretty much skip this step. Follow up with a coating of a good quality wax to seal the pores and prevent water spotting and oxidation.

I started with something easy like the clutch linkage cover. Mine had a few small nicks on the surface and several heavily oxidized black stains. In under an hour.... it is now like a mirror.

For larger parts that would be awkward to hold against the wheel..... there are flex shaft attachments for as little as $40 that will attach to 1/2 shaft grinders and use 6" wheels that will allow you to take the wheel to the part instead.

Once you've practiced for a bit..... you should quickly learn the amount of pressure on the wheel that will yield the finest results. The only thing you can really do wrong is holding the part against the wheel with too much pressure for too long and discolor or "burn" the surface... but even that is easily removed by recutting over the bad spot. Oh.... and another thing to watch for is to work the part with any hard edges or angles away from you since they have a tendency to catch the wheel and try to tear the part from your hands.

There is plenty of information available online on the topic even though I have restated some of the basics here.

[Shuriken]

Thanks for all of that Jeff. That's exactly what I wanted to hear. Now for the tedious question.....

For the materials you mentioned, rouge, tripoli, cutting wheels...

Do you have a source and approx. price and part numbers for those items?

Ben

[Racer X]

I was going to have my aluminum parts anodized this winter.
Has anyone else done this, and what are the pros and cons of it?

[nashville_bill]

Ben, try http://www.caswellplating.com/buffs/...c831b6a4164a01 for a guide for prices on all buffing supplies and information.

[Jeff]

Most larger hardware stores carry all the needed supplies or you can get them online at places such as Caswell. I purchase all of my polishing supplies at Home Depot. Harbor Freight carries them as well.

The wheels run anywhere from 4 to about 7 dollars each. The spiral sewn wheel is the stiffest allowing the most pressure to be applied against it. The wheels are made of many disks of fabric sewn together at the hub. A spiral sewn wheel has the disks sewn together in a spiral stitch starting at the hub and spiraling out to about an inch or so from the outer surface. This stitching holds the disks together more firmly. Medium wheels have one or two circular stitchings holding them together with the outermost approximately halfway out from the hub. A soft wheel is only stitched together right at the hub. Then you factor in the actual material used for the disks..... with sisal or sisal/cotton being the stiffest, cotton next, and then flannel as the softest.

The abrasives come in sticks ranging from about 3/4 inch in diameter to over an inch. Some are round and some are square. Most will be quite waxy or greasy since that material is what carries the abrasive and sticks it to the surface of the wheel. To put the abrasive on the wheel... simply run the wheel and rub the end of the stick against the wheel. The friction melts the carrier and sticks it to the surface. Waxy or greasy sticks will leave their residue on the material being polished. They also make greaseless sticks that leave no residue which tends to work better on items with holes or depressions that can collect residue from the greasier sticks requiring more cleanup afterwards. I prefer to use the brand carried by Home Depot because instead of being a loose stick which can sometimes get a little messy, they cover the stick in a spiral wound paper tube that you peel away as needed to expose fresh stick sort of like a big grease pencil. The abrasive sticks run from about 3 to 6 dollars each. Some manufacturers may use a different name for the abrasives but will have a chart on the back stating their main purpose. Tripoli is generally brown, white rouge is of course white and jewlers rouge is red. They also make an emory compound which is a heavier grit abrasive for use on parts that have larger pits, rougher surfaces such as cast parts or parts that have been milled leaving milling marks such as can be found on the Tkat fork brace. I generally use only 3 compounds. If the surface is already smooth with no pitting, staining or scratches.... you can get away with just the two finer grits.

To be the most effective.... it is always a good idea to have a seperate wheel for each abrasive. You will also need to occasionally clean the wheels using a wheel cleaner tool or a piece of large tooth saw blade to loosen and fluff the surface of the wheel and keep it from getting all packed up with debris. For finer detailed work... they also make cotton bobs which are essentially wads of tight packed cotton on the end of a metal shaft that can be used in a die grinder.

All in all.... if you already have a decent bench grinder just take the wheel shields off.... you can get everything you need to get started for 25 to 30 dollars. It is VERY easy to do and yeilds excellent results. I also advice a good pair of leather gloves for better grip, protecting your fingers from the wheel, sharp edges and most of all the heat generated from the friction. Eye protection in the form of some sort of shop glasses is a must. Most people also wear those paper dust masks to reduce the debris and abrasives dusts being inhaled. So... go ahead and give it a try. It is very rewarding to see a part get shinier and shinier as you move thru the wheels.

[Geezer]

Re: Metal Polishing

Originally posted by Jeff

Now that I've gotten bit by the shining bug..... I was wondering if anyone else has found polishing metal to be a relaxing past time? I spent several hours this evening working on a few parts and when I was done..... other than my arms being a little tired.... I felt refreshed. LOL I can't wait to see the parts in the sunlight tomorrow.

I used to have polishing equepment when I had my shop (acctualy it was my partners) and there wasn't a removable part on my old BSA 650 that didn't shine like silver. Quite often I had to work over rough areas with 600 grit or finer sand paper.

Polishing equipment is on my get list. There's nothing like a gleaming engine.

Geezer

[Jeff]

On heavy nicks and gouges I block wetsand it smooth first. Tripoli on the wheel makes short work of the sanding scratches from as coarse as even 220 grit wet/dry paper. For lighter scratches and roughness I wetsand with either 400 or 600 grit. I prefer to use a sanding block when possible to help eliminate the wavey or rippled look you can get just sanding by hand. The shinier something gets.... the better you can see even the slightest imperfection.

[JerseyJon]

Bump and a question

I think this is a very good polishing tech tip, especially for those of us who haven't done it a lot. Not only does it describe the process well, but it also tells you what products to buy and where to buy them.

Here's a current question: There is discussion upthread (No. 5, for example) about a shaft extender that one can attach to one's benchgrinder and thus use it on larger parts. That seems a little cumbersome. Has anyone ever tried using an angle grinder for cleaning/buffing/polishing? If so, how'd ya do it? What kind of wheel did you use? I poked around at Lowe's, HD, and HF but really couldn't get an answer.

[crazy steve]

Has anyone ever tried using an angle grinder for cleaning/buffing/polishing? If so, how'd ya do it? What kind of wheel did you use? I poked around at Lowe's, HD, and HF but really couldn't get an answer.

I've done this for large pieces (car wheels that still had tires mounted), but it's rather clumsy. It's also very easy to nick the piece if the shaft hits the part. The main problem is the smaller angle-head grinders won't spin a large buff; you're limited to a 6" max size, a 4" is better in terms of power available. If you have a larger 7" grinder, you can spin a larger buff with better results; up to a 10" buff can be used, but be aware that the larger buffs give better 'leverage' and make controlling the tool harder. You really need to clamp either the part or the grinder down solidly; trying to hold both items can get exciting....

Besides the tip in the tech forum, there's this:
http://www.xs11.com/forum/showthread...ghlight=polish

Buffing can be labor-intensive; the better you get the surface before buffing, the easier it is....

[JerseyJon]

Thanks again

Yes, that polishing tip is really excellent. Thanks for doing it, posting it, cataloguing it, and linking it again.

[fredintoon]

Now that I've gotten bit by the shining bug..... I was wondering if anyone else has found polishing metal to be a relaxing past time? I spent several hours this evening working on a few parts and when I was done..... other than my arms being a little tired.... I felt refreshed. LOL I can't wait to see the parts in the sunlight tomorrow.

Hi Jeff,
know that polishing can turn from a pastime into an obsession.
Also, take care to keep the debris out of your eyes and out of your lungs.
You don't want to be the half-blind asthmatic guy with the shiny bike, eh?