hi,new and need a little advice...

[jambo]

hi all,scot living in ireland since chidhood,have two lads one 21 and one 14,good lads,train u14b local soccer team,love doing it with them,feel like im almost still playing ,any way heres the problem im finding with polishing up a aluminium frame from a motorbike,it was quite badly scratched so i went at it with a greaseless 80 git compound,then a 150 and then a 300,first mistake im thinking....im getting a ripple sort of effect,should i just use a 80 grit and then move on to a polishing compound with a spiral mop
not really to sure read somewhere and saw the kit on sale here,and that seems to be the way,hope someone can tell me the correct way as my arms are nearly broke trying to get rid of the ripple effect.cheers.

jambo

[Rasper]

Whenever I sand any sort of tube for finishing, the only method I have found that doesn't produce ripples and waves is to wrap the sandpaper around the tube, squeeze hard, and move it up and down the length of the tube. An alternate method would be to use good cloth backed sandpaper and do like a shoe shine boy does with his cloth on the toes of your shoes. You would have to do this near the joints in the frame, obviously, and you could use this method throughout, but sanding along the length of the tubes would be better, give you a smoother result.

A method to remove the waves and ripples you have put in there would be to use a file, cutting only along the length of the tube, never across, until the ripples are gone. Then you would then sand it as I described.

A photograph would help us to give you exact advice.
R

[vortechyank]

Welcome! No, definately don't stop at 80 grit, they are pretty deep scratches and you must move through the series to remove the previous scratches.
My million dollar question would be, what media are you applying the greaseless to? A mop, a drill buff, a wheel etc, and what size? I find i get the ripples with my dremel because the 1/8 size is too tiny and digs in along the uneven curved aluminium as you move it. Usually, when you keep progressing however, and get to buffing, it tends to disappear. Spend alot of time on the emery black compound too, really give it a good going over and for a while too, that evens it out alot. It's all preperation and it doesn't take much to bring up the final shine with brown and then the color compound.
Rasper has given great advice with the sanding around the contour of the tube, this always gives nice, even results and hides alot of imperfections, as the light hits it from every angle. The same way you spin a piece on a lathe and work it around the same direction

[jambo]

thanks for the ideas,the piece is a large frame so hand sanding it is out of the question,im useing a drill with mops 6",cant put pics up as ive lost usb cable,when i grind with the 80 grit it seems smooth and reletavley ripple free but as i progress down the grits that is when the ripples start to show more,it gets to the stage where you can see the lovely smooth mirror finish but it is rippled all over,the kit thats for sale here only has the three stages and the help tutorial tells you to only do the three stages bit confused i have to say......

[jambo]

ok,i used 80grit with a sisal and then a close stiched white mop with grey first stage polishing compound,then buffed,good results nearly scratch free,tried again with 80,150,300 grit and the ripples just comes back,can someone on here with there vast expierance not help me??

[Rasper]

The word ripples can mean different things to different people. We need to see what you have to really give you good advice. Please borrow a USB cable.

If you are going at your tubular frame across the tubes with 80 grit on sisal, you are being super aggressive. Even on steel that would be dangerous, even in the hands of a professional. When you think of polishing metal, think of a mirror, or a pool of still water. It is absolutely flat. Your metal must be that way. I would think it almost impossible to cut across an aluminum tube with 80 grit on a sisal mop and maintain any kind of regularity in your surface.

R

[vortechyank]

80 grit with a sisal, that is very very very aggressive. I would recommend just moving through the greaseless grits, on regular wheels that offer no cutting action themselves (even 80 grit here is very very coarse, for cast or VERY deep scratch/gouges) and then proceed up until the 300/400 ish mark, then hit that with a regular wheel and the emery and let us know how you go. Pics would really help

[jambo]

thanks for the reply's,i will try and get a usb cable to show you what im talking about.
cheers

[cddesigns]

You need to look at the thread titled "greaseless leaving orange peel". I think this might be your problem

[jambo]

ok finally got a loan of a usb cable,here's the pics....


i used 80 grit on a cloth mop,then 150 followed by 300,i just cant get rid of it,the rippling comes up after first stage with 80 and stays threw all stages,it's really getting to me now