Working with my new (to me) machine

[felgenpolier]

I recently purchased a 12 H.P. polishing machine. I will be mostly polishing aluminum wheels



It only spins at 1450, but it has god like torque.

Using the wheel calculator, I estimate that 450mm polishing wheels will give me the proper speed.

My previous polishing experience has been with my drill and a polishing kit, so this is a big step up.

Until I found this site, I was unaware of polishing, cutting, and buffing. Everything I did was polishing. I was always able to get a good shine, but some jobs took much longer than others. My final shine always seemed to be a step under "professional".

I have read all of the must read material on this site (very helpful), but I still have a few questions?

I am still not 100% clear on "cut and color"....

I will try to answer my own question, but maybe others can chime in to verify...

From the Caswell diagram, I contact the same part on the buffing wheel, but it depends on which way I turn my rim (item to be polished). Turning one way will poduce the cut and the other way will produce the color.

Does "cutting" refer to sanding and removing scratches?

Does "color" refer to the shine?

I know these questions are very basic, I have more questions, but these will get me started.

Thank you

[mpierich]

In my opinion, the cut stroke (against rotation) is more agressive than the "color" stroke. In actual fact I don't think there is much difference in the amount of material (metal) removed or burnished.

However, something no one ever mentions is the fact that the color stroke (with rotation) will better remove stuck compound from the surface...therefore, used as the last stroke, it will clean up the surface. And furthermore, if one is having a hard time removing the stuck-on compound, it actually helps to overload the wheel with compound (contrary to what you would think...).

Did you really say Twelve Horsepower? Holy cow...

[Rasper]

Your machine is too slow to be ideal. Torque is not a particularly good thing here. It can even be dangerous to your work. What you want is the right speed and enough torque so that when you need to bear down on it with emery it doesn't slow way down.

A 3450 rpm machine with a 6 or 8 inch wheel is a good combination. If your machine is driven by an external motor and a V-belt you can double the diameter of the motor pulley and achieve this.

What mpierich said is an excellent take on the cut and color question. He knows his polishing.

Mostly the main mistake that inexperienced polishers make is that they don't completely polish/sand out the scratches left by the previous process before moving up to a finer grit. The result is they just get shiny scratches.

There is no teacher like practice. Get yourself a car wheel and practice on it. Start sanding and polishing. You can't hurt it.

Richard

[felgenpolier]

QUOTE:
In my opinion, the cut stroke (against rotation) is more agressive than the "color" stroke. In actual fact I don't think there is much difference in the amount of material (metal) removed or burnished.

I tried working it both ways and to my untrained eye I didn't note a difference.

QUOTE: Your machine is too slow to be ideal. Torque is not a particularly good thing here. It can even be dangerous to your work. What you want is the right speed and enough torque so that when you need to bear down on it with emery it doesn't slow way down.

With my 400mm (15.7 inch) wheel, my SFPM is just under 5800. Once my machine is at 1450, nothing is slowing it down.

QUOTE: There is no teacher like practice. Get yourself a car wheel and practice on it. Start sanding and polishing. You can't hurt it.

That seems to be the best plan. So far, I am very happy with the results. I am a rim collector so I have lots of material to work with. I will post pictures soon.

Thanks for the replies!

[alabama_lowlife]

if you take a work piece and do a "cut" on an area....lets say 4" wide which is obviously several passes, be very deliberate in your movements...then right in the middle of that area "color" one strip right down the center, you'll see the difference. at first, i didn't really try to maintain any form to my polishing, but after some time i finally noticed the difference and understood the function of each of those motions. and now i realize why they call one of them "cut" and the other one "color".

[felgenpolier]

Well, after several hours of fun, I am slowly seeing the difference between cut and color. I didn't really understand the term color until I started seeing my reflection on the wheel. The nicer the shine, the more colors I could see.....

(light bulb above head) OK....so this is color!

I have read over most of the threads here and the advice is great. I didn't understand everything while reading it, but once I started working I understood the advice a little better.

I started most of my work with a sisal wheel and black compound. It did leave some fine scratches, but they were easy to see and it was very uniform. (much better than my hand sanding attempts).

After the black compund, and a very good cleaning I moved to the red compund and a different wheel. As I polished, I could see the shine improving and the small scratches filling in. As I started getting aggressive with the pressure, the heat started building up. When I was done I noticed some blotchy type of reaction that refused to buff out. I'm guessing this was due to the heat......if this is the case, what do I do to remove the cloudy look?

I know that you are not supposed to use different compounds on the same wheel, but at the moment I am still expiermenting. Is it possible to rake the wheel and switch to another compound? I dont want to switch constantly, I just want to be able to expierment a little.

I will post some pictures next. Thanks for any input.

[mpierich]

Well, if you don't change wheels you're peeing into the wind, my friend. Just a tiny amount of a coarser compound will negate the finer compound.

Try black/spiral cotton after the sisal to get rid of the sisal scratches.

Going to red after the black is a bit of a leap. You oughta try white (which is where I usually stop) or brown tripoli first. Red is more of a finishing touch, to me.

It takes a LOT of heat to really discolor aluminum. Chances are you're seeing areas that weren't gone over the same as adjacent areas. Drop back a step or two and see if they don't go away.

Originally Posted by felgenpolier

Well, after several hours of fun, I am slowly seeing the difference between cut and color. I didn't really understand the term color until I started seeing my reflection on the wheel. The nicer the shine, the more colors I could see.....

(light bulb above head) OK....so this is color!

I have read over most of the threads here and the advice is great. I didn't understand everything while reading it, but once I started working I understood the advice a little better.

I started most of my work with a sisal wheel and black compound. It did leave some fine scratches, but they were easy to see and it was very uniform. (much better than my hand sanding attempts).

After the black compund, and a very good cleaning I moved to the red compund and a different wheel. As I polished, I could see the shine improving and the small scratches filling in. As I started getting aggressive with the pressure, the heat started building up. When I was done I noticed some blotchy type of reaction that refused to buff out. I'm guessing this was due to the heat......if this is the case, what do I do to remove the cloudy look?

I know that you are not supposed to use different compounds on the same wheel, but at the moment I am still expiermenting. Is it possible to rake the wheel and switch to another compound? I dont want to switch constantly, I just want to be able to expierment a little.

I will post some pictures next. Thanks for any input.

[berndog]

!2 HP eh?? WOW!!!! I'd like to see how that works holding up a 24.5 alcoa to it,,,like to hear how its coming,,I'm thinking of expanding business and buying big machine.