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Polishing wheel
#1
Its time to start thinking about polishing up some of the brightwork/chrome that has to be put back on the car.
I want to purchase a polishing wheel/machine. What RPM is the minimum i need to perform a decent polish?

Steve
1971 Grandé
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#2

Polishing of the trim and also of the paint finish is done at a slower RPM that grinding. So a pedestal grinder is not the best choice for buffing. Just like using a side grinder would not be a good choice to put a buffing pad on to do your paint. Equipment suppliers usually distinguish the difference and call the Buffers or Grinders. If you are trying to say buff out your instrument panel lens you need to use something very slow and the headlight polish to keep from melting the plastic.
You will need to get several different grades of polish and never use the same buffing wheel for different grades. I keep my buffing compound sticks and the buffing wheel they go with in plastic bags so I do not mix them up.
When you are first starting you have to remove all the anodizing from the aluminum. You will find many posts on the forum on that topic.
If you are buffing like the stainless trim around the windshield of a convertible you do not have to do anything unless you have dents.
If you have dents in your trim you will need a good flat surface to push the dents back out. Do not hammer on them unless just lightly. Massage the more than hammer them.
You need to find some video showing how to buff your parts. If you do not do it correctly the buffing wheel will catch the edge and bend your trim before you can blink an eye.
I worked in National Lock Cabinet Hardware. We had rows of buffers and two plating lines. We always had someone out of work with a broke finger hand or arm.
NEVER wear loose gloves or loose clothing. The buffing wheel tends to grab onto clothing and can also be dangerous. You should change the wiring on your buffer so that you have a Dead Mans foot switch. That is a pedal that when you take your foot of it the current is broken to the buffer. We wired all our drill presses and buffing machines this way so you did not have to reach for a switch it you were in trouble.
As with any type work you have never done there is a learning curve. If you buff too much there will be  a hole in your trim. I usually use two grades a rouge that is for getting the big scratches out and then a fine that is usually white in color for the final buff and then I do a hand buff with aluminum polish cream.
Here in the U.S. you can get a pretty good buffer at Harbor Freight I have one been using for several years and still runs great. It is better to mount to a pedestal so that long pieces can be put into any position.
Again catching an edge will grab the part out of your hand for sure. I would practice with a junk part to get the hang of it.
The buffing pads or wheels come in couple different configurations. The more they are sewn together the more cutting they will do. The wheels for final buff are not sewn close to the buffing surface but are loose layers of cotton usually.
The parts will heat us so keep several handy so you can switch off to let them cool. When switching grades of compound be sure and wash the parts thoroughly so you do not carry coarse material into your fine buff.
When I use to polish molds I kept my different grit stones in different containers so I did not contaminate each other.
I just did some antique Wagner aluminum post the other day to put in yard sale. They were beat up pretty bad so I actually started with 500 grit sandpaper, then 1,000 then red rouge buffing compound then white then the paste by hand. They look like new now. I have done antique hand drills and power saws and sold on ebay also. Good polish catches the eye for sure.
It does not take long and is easy once you know where not to put your part on the buffing wheel.
Always try to stay below the center line of the wheel and stay away from catching edges. Long skinny pieces should be polished long wise so the edge does not catch. When you come to and end point the end down toward the floor so the wheel is pushing away from the edge.
Sometimes I do wear tight fitting shop gloves but not often.
I might try to take some pictures of positions of parts to the wheel tomorrow to better show what I am saying.
Most people get too carried away with trying to make them too good. If you cannot see the defect from arms length I doubt anyone viewing your car will ever see it.
I did a set of Dr. Scales made in the 1920's had been sitting outside for years. I think I paid $15.00 for them. I put the steel and iron parts in my molasses tank and took all the rust off. When I took the balance beam apart I discovered it was all brass so I just polished it some instead of taking to get Nickel plating put back. When I weighed on the old scales and new digital within 1 pound of each other.
Pics of the pots and scales. I did all the stainless on my 73 vert and the aluminum trim on the tail light panel and the aluminum / stainless pieces that hold the rubber seal on the A post. I have some several pieces of trim I stretch wrap and put away. I switch tasks when I get bored doing body repair I go polish. When I get tired of car I work on furniture or something else. I love to learn new skills to use in different areas.
BTW I just wash good with lacquer thinner and spray clear over the parts to protect from the air so they do not tarnish so fast.
David
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When a man is in the woods and talks and no women are there is he still wrong??
Tongue
David
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#3
Depends on the compound you use and the kind of metal. I personally prefer low rpms and have water in the mix. No burns/heat.
My polishing wheel broke like 3 years ago and haven't replaced it since. I wasn't really comfortable with it and was doing most using portable tools to better feel the part anyway. One thing I liked in this old machine, was that it was heavy, it took a while for it to be at cruise speed, no rpms idea, but then even at low rpms, torque was there and you could apply pressure without much loss of rpms, even with a wide cloth brush. Now days, they probably all have variable speeds, and have these handy quick axle to change wheels in a sec. Mine was with bolts and you wouldn't do it because it took too long to change.

Next I'll buy will be something like this one, except I would install it on the wall, vs on a table and have an optional cover so the water/mix doesn't come back at you too easy.
https://www.sportsmansguide.com/product/...e?a=908067

73 modified Grandé 351C. Almost done. 
71 429CJ. In progress
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#4
Thanks for all the info. Looks like i got a lot to learn about buffing for safety reasons mostly

Steve
1971 Grandé
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#5
I agree with David and Fabrice about wanting a lower speed for polishing. Just for the heck of I looked online for some benchtop polishers. Most were 3.450 RPM, even the ones for 8-inch buffing wheels. I did find one that said variable speed, but then it didn't specify the speed range.

At 3,450 RPM the outer edge of an 8-inch buffing wheel is traveling at 80+ miles per hour. How can anyone keep any compound on at that speed, not to mention how fast a part could get launched if it got caught in the material? Another issue I have, none of the buffer wheels I could find online had an RPM rating.

David's comment about shirt sleeves is spot on. When I was around 16 or 17 I was using a wire wheel on a bench mounted motor, my sleeve caught and wrapped my arm around the wire wheel before the motor stalled out. The on-off switch was within reach, so I didn't have to stand there with the wire wheel trying to rip my arm off while I was pulling the other direction. No damage except for some scratches and punctures, I was lucky. His idea of a dead man switch is excellent, I'm going to look into one for my drill press, even with a vice on it I've had things get away when the bit hangs up.



“If you can't explain it simply, you don't understand it well enough.”
--Albert Einstein
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#6
(06-11-2018, 04:43 PM)Don C Wrote:  At 3,450 RPM the outer edge of an 8-inch buffing wheel is traveling at 80+ miles per hour. How can anyone keep any compound on at that speed, not to mention how fast a part could get launched if it got caught in the material?

I've twice launched parts into orbit Smile 
One was during cleaning a drum brake tension part. brush was non metal, but I was holding the relatively small part with some pliers. Very bad idea.
The thing was not even in contact with the wheel, it went sky high and landed somewhere on my neighbourgs terrain above a tree. Had a vague idea on where it could have landed. Looked for ages with no luck. Its only like 2 or 3 years later, when some work needed be done on the separation between properties that I found it back. Not even looking for it, but after all this time, rust gave it a bright orange color that made easy to spot. It's now back on the car.

Second one was using a milling machine, a +- 10k rpms thingy, when I was making my steering wheel. I had per side cut 4 1/4 of the wheel circle and was busy on their profile. The wood was soft and the machine rotating very high rpm's has no problems to do the job. Always careful with this thing, I never put my fingers near the bit and always secure guides. Being 1/4 circles, in this case, it wasn't the usual "push along the guide" case and had a few done already with success. At some point, the bit hits a hidden knot in the wood. The bit transfered all its rotating energy to the wood and poof, the wood piece was gone in the instant. No idea where it went, no sound either. So I suppose it went thru the open door. Never seen it again.

So yeah, you can never be careful enough and should always consider what could potentially go wrong each time you use one of these. Routine is not your friend. Never use them in a hurry and always wear adequate protection. I'm pretty strict on myself in that regard, but I know one day, I'll put my guard down just for a bit...

73 modified Grandé 351C. Almost done. 
71 429CJ. In progress
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#7
Glad some have first hand near misses to share.
I was a tool & die maker for many years so you respect the speed at which something can happen. I was safe enough that I never lost a finger I did mash my fingers under a heavy die set once and Dr. had to drill several holes in fingernails.
I read some about adding water to the mix. I would not suggest that. The buffing compound is made to melt and stick to the buffing wheel. You also take a screw driver and while the wheel is turning fluff it up occasionally. The do have a star wheel dresser for buffing wheels to sort of fray the ends some.
When buffing paint with a lambs wool pad I also use a screw driver to fluff up the pad and get rid of the matting in the pad. 
Here is the link to the one I bought several years ago. https://www.harborfreight.com/6-in-buffer-61557.html
I was working on a player piano at the time and needed to polish the ivory keys and some brass parts. I use for the car parts also. You can see the two types of buffing wheels on the head. One on the right is sewn tight for roughing in the polish and the one on the left is loosely sewn for final polish. If you buff too much you get the surface uneven and it looks odd. If you have really big deep scratches you sand them out before buff.
I like to take the buffer outside and have the cast iron stand that Harbor Freight also sells. I stick camping tent stakes in the holes of the stand to keep in place. There is lots of black trash and threads and buffing compound flying off all the time so outside keeps the shop clean. I do some inside also but have to  clean up a mess after.
It is something anyone can do but please do watch some videos and be careful.
I had a cousin that was also a tool & die maker. He was using a pedestal grinder and the wheel blew up and a piece was launched into him. It went into his liver and he bled to death before EMT could get him to hospital. We always "Ring" test a grinding wheel before mounting but they still fail sometimes. I had two explode  while working in the shop. One was on a tool post grinder and I was hand dressing the wheel with a Norbide stick when it just disappeared. I was still holding my hand there and there was no wheel. I did not have time to move. The other was on a precision surface grinder. Again I was dressing the side of the wheel by hand and pow it was gone. It is impossible for you to react to any mishap with a grinder or buffer quick enough to not get hurt. You have to be careful.
Over the winter I was cleaning the rotisserie I bought to paint it. I had been using a side grinder and heavy cup wheel wire brush. I wore safety glasses and Kevlar gloves. I was sitting on roll around stool with a concrete block in front of me to rest the parts on. I had made it a point to always keep both hands on the grinder one on trigger one on the side handle. I was down to the last small part one of the stabilizing legs about a foot long maybe 1 1/2' square tubing. The part kept sliding off the block so I held grinder in my right hand and held the part in my left hand. The brush grabbed and ran up the glove on my left hand and pulled it off. The wire brush started to cut into my hand between my thump and forefinger. It plowed down the palm of my hand and to my wrist and about half way to my elbow before It stalled because of the glove being wrapped around it. Blood was everywhere. I am always very safety conscious and have big first aid cabinet in garage. I went straight to it got bottle of peroxide and poured on my wound to see how bad it was. It came within MM of cutting main arteries to my hand. I went in and washed with dish washing liquid the bentodine and put bandage on. I did not bother going to hospital they would have done the same thing. Took weeks to heal but no permanent damage. Now when I have small part I head to the bench vise and I keep both hands on the grinder.
On washing my wound with dish washing liquid. I have gone hunting in Montana I believe 6 times and to Africa 14 times. I ask Dr. what we should do if someone got mauled by a bear or lion. He told me to wash with dish washing liquid to kill the bacteria from the animals dirty mouth, then peroxide and bentodine if not a very deep wound.
So maybe I should make some pictures of the Do Nots and Do's of buffing.
Picture in my work room you can see the buffer in the background.
David

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When a man is in the woods and talks and no women are there is he still wrong??
Tongue
David
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#8
(06-12-2018, 11:27 AM)Carolina_Mountain_Mustangs Wrote: I read some about adding water to the mix. I would not suggest that. The buffing compound is made to melt and stick to the buffing wheel. You also take a screw driver and while the wheel is turning fluff it up occasionally. The do have a star wheel dresser for buffing wheels to sort of fray the ends some. 
Yes true, if you use this kind of compounds only. I should have added that because there are bits of an "experimentalist" in me, found out for some uses, I could get same results or better and much faster using different stuffs and found out water was also best addon for these. I also have tried with oils. I had a few wheels per type of stuff I was using, tho to be honest, I have mixed wheels and compounds at times, too lazy to unbolt the wheel for that small quick thing I needed.
Back then and to these days, my two best friends are Belgom and a RM paint compound that I have in a tube and these work much better with water.


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The paint compound on this pict, is not designed to be used this way at all nor for the use I give to it and its certainly not marked as excellent alumimium polish but fact is: It is a damn good aluminium polisher when water is in the game Smile 

On the right, one of my last compound block, for these, I would apply/push it on the wheel and no water was used. 
Pretty much what you described and indeed the proper way to use these.

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Not often viewed as polishing tool, I also use a Dremel for small items. Also set on lowest possible rpms so I do not get a face makeover in the process. Here for instance, some work on the rear tail light harness ( that @midlife dared to ship to me unpolished!!! Smile ) 
left before, right after.

73 modified Grandé 351C. Almost done. 
71 429CJ. In progress
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#9
I now get the same result on tail light sockets by simply going to a wire wheel machine. 30 seconds later, nice and shiny. I follow up with Boeshield T9 as a metal preservative.

Let me check your shorts!
http://midlifeharness.com

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#10
Looking forward to see that on the 71 harness that you will do soon Wink

73 modified Grandé 351C. Almost done. 
71 429CJ. In progress
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