HELP WITH GETTING OUT PITS IN ALUMINIUM WHEELS!!!!

[johnnyb]

I have attempted to try to polish the wheels on my 95 trans am, and i haven't had very much luck lately. first i stripped the clearcoat with aircraft stripper, then i (attempted to) removed the silver paint on them also with the aircraft stripper. now what i am left with is a million pits all over the wheel! i have sanded out most of the pits on the face of the wheel by hand/palm sander/pneumatic sander (80, 100, 220 grits) after about 10 hours!! and that is just the flat surfaces!!

my question is, why does the wheel have pits in it? (i am starting to think that it could be from the stripper that i have been using?)

what is the fastest way that i could get the pits out? (different tools than i have been using).

any shortcuts for the curved surfaces?

how would everyone here do it? i couldn't imagine anyone spending 15 hours per wheel at just sanding out the pits.

i have been told that i should get it bead blasted, would this get out the pits?



Sorry for so many questions, but i have just been very agitated with all these pits and i am contemplating repainting them, selling them, then buying new ones because i am thinking that this may not be worth all the hastle unless there is an easier way to do it.

[mpierich]

You may never get the pits out. They _may_ be "pores", or bubbles that formed when the metal was first cast. The more you sand, the more will show up.

I'm not a plater, but I have a thought that if an item like this were copper or nickle plated, then ground and polished before another few layers of plating, that the copper might act as a filler and take care of the pores.

If you want to keep grinding/polishing, for the curved surfaces I imagine you should use greaseless compounds and/or setup wheels, which are cloth wheels coated with glue and rolled in loose abrasive. All are available (w/info) on this site.

Good luck.

[johnnyb]

thanks, but i am pretty sure it is not pores in the aluminum, because i have got alot of them out of the wheel already. would the greaseless compounds be abrasive enough to sand down the aluminium? thanks again

[johnnyb]

i have been reading about this greaseless compound, but now my question is: would it be better to use emery on a sisal wheel or a greaseless of 120 grit on a spiral wheel? which would be more abrasive?

[mpierich]

Regardless of what I have occasionally read in here, sisal isn't the monster you might think it is, especially on hard alloys like wheels. I would go with the 120 greaseless, or even 80-grit for fast removel folowed by 120/220/320.

I also like a setup wheel (which is a spiral wheel coated with glue and rolled in loose abrasive) for fast removal, but they are only semi-flexible and could leave flat spots if you're not careful. The great thing about them is you can make one out of any size/shape wheel, including making custom grinders out of felt bobs.

[mtmaher1]

i did the rims on my 96 cutlass. ONce you get the paint all stripped off they will be a rough cast. I sanded and sanded and sanded some more. Then I used a series of wheels similar to the vented buffing wheels sold here. They are from the Busch company. I stepped down with compound and ended up with this. I painted the holes that i couldn't get the buffer into.

[/img]

[pickleboy]

Originally Posted by johnnyb

thanks, but i am pretty sure it is not pores in the aluminum, because i have got alot of them out of the wheel already. would the greaseless compounds be abrasive enough to sand down the aluminium? thanks again

you may be confident the pits are not pores but if the rims are not solid billet(which factory rims are not) then the pits are most likely pores. the wheel is a poured casting that is then machined. the pouring process is not perfect and 99.8%of all castings have these pores/pits in them. (my dad used to work at a aluminum foundry making wheels) as for the polishing out if you get a lot of them it may be easier/ better to powder coat or chrome.

[MADMAXX]

I bead blasted my rims I think that is the best way if you have access to one

Here's how it came out

[MADMAXX]

I forgot to add that I sanded down all the deep wounds first. I got these wheels from a junkyard and the wheels where buried in 4 inches of mud

[pickleboy]

looks like a good start. keep us posted on the progress