back to basics - annoying (long post)

[rotorman]

OK, first of all, thanks to the creators of this forum. Polishing to me so far has been like a secret guild whose members do not want to let out any knowledge. Hopefully this\'ll change things.

I am a beginner. I have begun trying to polish metal in order to polish some parts of my car cheaply (and for a new hobby). I have recently bought a spindle attachment and two 6\" wheels for my bench grinder - one is stiched sisal, 1\" wide, the other is 2\" wide loose calico leaf. The parts I have in front of me are stainless steel from the looks of it.

Here is my problem:

I can get the part to mirror finish but on certain angles in bright light, scratches from the buffing are all over the surface - they are not deep - they are in the direction of the buffing and are near the surface.

I\'ll explain what I\'m doing in detail and maybe I\'m doing something really simple wrong. I couldn\'t find anything in the manual on this website. Maybe it is so simple it\'s not worth mentioning!

The surface is already flat (no scratches), so I used the sisal buff first with grey compound. I have cleaned the wheel with a screwdriver. I then applied the compound evenly. I have tried buffing by bringing the part to the edge of the wheel and keeping it still, rubbing it left-right, and moving it up/down - all are equally scratching. I don\'t know which one is correct! I am usually varying degrees of pressure - too much and it is bad, too little and it doesn\'t do anything. I have also tried wetting the part and keeping it dry. I just read that maybe I should be heating it up (it\'s cold here at the moment being in the southern hemishere). It is really scratchy but i can get some shine out of it.

Next, I use the loose calico buff with the green compound. This gives a really good mirror finish in all but bright light, but leaves scratches - finer ones than before (but does not get rid of the other scratches all together). Once again, I experimented as above, but also tried holding the workpiece stationary and moving it really slowly. Also tried varying pressures - the finish changes - but it is never satisfactory. I also tried going the opposite grain to the grey cutting - it just leaves scratches in the opposite direction.

My bench grinder is rated at 2850rpm, which according to this website is about right for a 6 inch wheel.

To sum up:
(1) should the buff be cleaned more aggressively?
(2) do the wheels need to be trimmed before use (ie with scissors or something)?
(3) where on the edge of the wheel should the piece be placed (ie on an angle at the very corner or flat against the edge)?
(4) what direction should it be moved (up/down/left/right)?
(5) what speed should it be moved at?
(6) does the workpiece need to be heated up?
(7) besides cleaning compound off, is any liquid necessary (like water on the workpiece when buffing)?
( should stainless when polished perfectly have scratches even if it is only on certain angles or am I just a perfectionist?

That\'s it...PLEASE hellp me!

[mcaswell]

Re: back to basics - annoying (long post)

rotorman wrote:
(1) should the buff be cleaned more aggressively?
(2) do the wheels need to be trimmed before use (ie with scissors or something)?
(3) where on the edge of the wheel should the piece be placed (ie on an angle at the very corner or flat against the edge)?
(4) what direction should it be moved (up/down/left/right)?
(5) what speed should it be moved at?
(6) does the workpiece need to be heated up?
(7) besides cleaning compound off, is any liquid necessary (like water on the workpiece when buffing)?
( should stainless when polished perfectly have scratches even if it is only on certain angles or am I just a perfectionist?

That\'s it...PLEASE hellp me!

1 - Sounds like you\'re doing an OK job cleaning the wheels. Keep in mind that the wheels should always be fluffy and loose. Don\'t let them get matted with compound.

2 - No, they\'ll fluff up within the first few seconds of use.

3 - Flat against the edge.

4 - Re-read our buffing book, paying careful attention to the Cut and Color motions. These two motions are key to getting a good finish. http://www.caswellplating.com/buffman.htm

5 - Speed of movement isn\'t really an issue. The speed of the buffing wheel does all the work. Move it at a speed at which you are comfortable.

6 - If you\'re in a cold environment, it wouldn\'t hurt to heat the piece to aid the buffing wax in melting.

7 - No need to use liquid.

8 - Swirl marks caused by buffing in the final stages can easily be removed by wetting the part with a damp cloth, then dusting with a powder such as:- Whiting, Talcum Powder or Corn Starch, then buff on your wheel again until the swirls disappear.

[rotorman]

Re: back to basics - annoying (long post)

Thanks again for the help

[saiyan7]

Re: back to basics - annoying (long post)

Rotorman, I beleive you speak on the behalf of all of us. We all have experienced the bain of spiderweb scratches and I think that all it takes is patience with each step, a clean buff, and practice, practice, practice. Caswell has been drilled over and over with the same questions. Most of the time by me and the answers are always the same. Caswell, I think it would be easier for you to hold a metal finishing show where you could show us your exact technique, step by step. How about making a video for us to purchase. You would sell tons of those and if I know you, a kit would be in order. Maybe a couple of 8\" wheels, the video, and some compound for around $50. I know I would buy one. Or at least put some teaching clips on your site. I know you could do it because you have a video of the handheld polisher on here now. Anyway, the better we are at polishing, the more stuff we buy from you.

[mcaswell]

Re: back to basics - annoying (long post)

A video is in the works....slowly.

>>I am still getting what appears to be scratching...

Try cleaning your wheels more often. It may be that little pieces of metal are sticking in the buff and causing scratches.

>>Swirl marks caused by buffing in the final stages can easily be removed by wetting the part with a damp cloth, then dusting with a powder such as:- Whiting, Talcum Powder or Corn Starch, then buff on your wheel again until the swirls disappear.

Did you try this?


>>How do you know when each step is done?
Experience. We always tell people to polish using the most abrasive wheel/compound combination until the part looks perfect..then move on the next and it should look more perfect.

[rotorman]

Re: back to basics - annoying (long post)

Thankyou.

[kirkacs1998]

Change your thinking. A polish is nothing but aligned scratches too small for our eyes to see. You have to start with 220 grit SP ensure all larger scratches are gone then go to 400 grit. Continue up to at least 1500 grit and then switch to either polishing compounds or a micro-mesh kit(see polishing by hand forum).DO NOT use a circular motion if polishing by hand, use straight lines. If using a machine, use a random orbital. A bit of background on myself to help my credibility. I am a Aircraft Structures Technician with the Canadian Airforce. One of my tasks is to polish the canopies on the CF-18(same as USMC F-1.

[rotorman]

Well, in case you didn't read the thread, I am polishing stainless steel, and to do all that sanding and polishing by hand would take hours and would be a complete waste of time. Stainless steel is rather tough and only buffing wheels make the job bearable.

Using a buffing wheel and black compound, I can cut out any sanding marks from 400 grit in about 10 minutes. The kinds of scratches i was referring to are those scratches only visible under intense light, and are WAY finer than 1500 grit.

I am getting the results i want now and i am using the methods suggested by caswell and other metal polishers. Having used the methods you describe i have to say they are inconsistent, involve far too much labour and the final result will never be as flawless as using a machine.

[kirkacs1998]

Maybe you didn't read my reply completely. At the end I recommended using a random-orbital sander. And it is possible to hand polish SS in a time efficent manner. I've done it.