Scratches & Haze

[mole]

I'm still pretty new to all this but a few years ago I was polishing the swingarm on my streetbike and I heated up a spot to much and it discolored it. So are you sure you didn't heat it up too much with all the polishing you have done so far. I'm not sure but I know it is possible.

[skiddz]

Sounds like you've got more than enough to think about now keny.. ehhe

I, like tom, get parts so hot they're uncomforable to handle with gloves on. I actually got my 6" sisal wheel so hot yesterday when polishing a piece of steel, smoke was comin' off of it! If you're not worn out after a polishing session, you're not pushing hard enough. We've all been as frustrated as you are. Keep trying and I'm sure you'll figure it out. There's no "magic" way to do it, everyone has their own techniques - ya just gotta figure yours out. It's taken me literally weeks to get to the point I am now and this group has been a TON of help in steering me in the right direction.

As for compound consumption, I bought a small bar of black almost 3 years ago and still have half of it left after polishing 12 truck wheels, every aluminum piece, all the nuts and bolts and a lot of the steel parts on my 4 wheeler. On the other hand, I've completely worn out about 6 sisals, 2 tight spirals and 1 loose cotton wheel on the 4 wheeler alone.

I spoke to a guy back East eariler in the week who is a Caswell's competitor and he seemed to really know his stuff. He said the best surface speed for aluminum is right in the 5000-6000 SFPM range.. With a 3650 RPM buffer, you're lookin' at a 6" wheel to get ya 5733.407 SFPM (Assuming Pi is 3.14159292.) I use 6" wheels and am having excellent results lately.

[kenykirschstein]

Thanks for all the advice....
I played some more last night.... it is a good thing I am single....
I worked with the black and I got the best shine to date, I have two observations that maybe somebody can confirm. One is that there is an inherent graininess to aluminum or at least extruded alumimunm that you will never get rid of. I had expected to get a shine that was so deep you couldn't see the base metal. Even though when you look at the metal at a reflective angle that is true, when you shine a light on it or at a certain angles you see the original color of the aluminum and a very fine graininess. I am thinking this is inherent and will never disappear. Right now the surface is just like wet glass and you can still see that at the right angle. The second is that cloudiness can be introduced into the base of the metal by inconsistent heat when polishing. I found that if you don't heat it equally in all areas you can get a cloudiness that looks almost like when you heat something and you see the transition line between what was heated and what wasn't. I played with this and if I am consistent and controlled in using the right pressure I get a shine that was clear of any cloudiness. Maybe someone can tell me if I am correct or I'm just imagining things....
After finally getting a finish that I was happy with, I moved to the white.... I played with my 8" and I could get the part hot but it still looked worse, I tried a 4" with grinder, I have a variable speed grinder so I am able to keep the surface speed down, but it also gave bad results. With the grinder I got it really hot and it seemed to make no difference, so hot that it started to discolor the metal. I tried a couple more variations but no luck. All the results dulled the shine a little and added a slight haze to the shine. I could immediately go back to the black and clean it up without any problem.
I am at a lose as to the issue here, but I will order the 6" inch wheels as suggested and try that.... at this point I am very sketical of it fixing the problem.

[bhhodges]

where did you get this aluminum from, i want to try a piece on my buffer?? if its from a national chain i will buy a piece and see what result i get.



bill

[kenykirschstein]

Bill....

Thanks for the offer, may I suggest that I send you a piece along with a piece I polished. That way you can compare the two and see what results you get. One thing that is hard to do in a forum is get feedback on the finished product. You just can't take a picture that captures the true finish. I would really welcome your input and find out what limitations are inherent in the metal.

[bhhodges]

send me the one you did and ill do a piece and also send a step by step of what i did i like a challange . ill pay the postage of both back to you as well.

e-mail me at srlutc@aol.com

[bhhodges]

on the sanding of these pieces did you hand sand then up to 600 or power sand up too 600 grit?? also are you sure these pieces arent anodized----from your first posting it sounds like they could be anodized??


bill

[kenykirschstein]

I power sand at 150, hand sand at 220 and wet hand sand at 320 and 600. I also have also tried variations of sanding on a 24" by 32" plate I started on, and found a difference between sanding with the extrusion grain and against it. I sanded it completely down to no scratches with the grain, I then buffed it with sisal and black. You could see the grain of the extrusion and I found if after a first pass of sisal and black wet sanding at 320 and 600 across the grain gets rid of the extrusion ridges and gives you a perfect finish when buffed again with the sisal and black.
As far as the anodized question, I don't believe it is because all anodizing I have seen result in a different color. However I could be wrong, but I think what you are reading in my posting is my attempt at describing the finish created by hot extrusion which seal the surface of the aluminum.

I sent you an email about sending you the sample...

[bhhodges]

could you please resend i could of possibly deleated it.

srlutc@aol.com


bill

[kenykirschstein]

Bill....

I resent the email yesterday, maybe its easier if you send me one...

keny@elsouth.com