Polishing in General

I see You cats feverishly prepping/polishing various bits, slowly reducing the aggregate size on your wet/dry sandpaper to almost 100.000 grit. You know that is not necessary? I rarely go below 320-400 and then polish. It's ALL in the Rouge and Wheel you're finishing out with. I do a crap load of polishing, not because i enjoy it but because an engine isn't complete without it. Really no short-cut, but waaay easier then what i've noticed a lot of fellas doing here!     

What would you use on clear plastic?

SWest wrote:

What would you use on clear plastic?
 

I've been planning to try one of those Mr. Clean "magic erasers" followed by traditional polishing compound, but lately have been leaning toward emulating the headlight-polishing kits.

Probably depends on the type of plastic - e.g. Lexan vs acrylic - but I have a couple of windshields that won't really look any worse if the experiment fails.

I'm a big fan of black cutting compound and a sisal wheel.  That brings the brightness up to OEM level.  

If the part is heavily corroded, you have to remove the pitting first, though.  A DA sander with 220 grit paper works well for larger parts like side covers.  Or, a 3M deburring wheel on a grinder/polisher will work even better.  In fact, I often stop there, and the part looks sort of brushed finished.

 

Steve i've never polished clear plastic so couldn't tell ya? Like Nerdy mentioned i suppose depends on plastic compound. Nerdy, isn't that "clean eraser" just a sponge with impregnated grit?   

asphalt900 wrote:

Nerdy, isn't that "clean eraser" just a sponge with impregnated grit?   

 

I'd say they're more like very, very fine Scotchbrite pads. They're minimally abrasive (no added grit), so they're less likely to cause damage. They appear to be less abrasive than 0000 steel wool.

Although some morons discovered they can remove tooth enamel

Clay you must have a beast of a polisher, my set-up (old bench grinder) would take ages to get sanding marks from 340 out - I use 320 - 600 - 800 then three stages on the different buffers (course medium and fine) sanding to 800 means the parts buff up in minutes

Clear plastic, but same applies to colored really... I've done some headlights
I do 600, 800, 1000, 1200 on a hard or soft block depending on the feature. Then Meguirs heavy cut 110, and finally 210 finishing. This works amazing... Just took off a bunch of melted deteriorated plastic that someone tried to remove from a headlight with acetone or similar.

As for aluminum stuff, you guys need some scotchbrite bristle wheels for your bench grinders. I welded up a side cover, filed the rough shape, finished with 80grit on a block and then used the bristle wheels to remove the sanding scratches and get the shine going. It's not perfect, as I missed some file scratches with the 80 grit but eh.

Repeating myself, sorry, but these side covers were sanded with a DA and 220 grit sandpaper.  Then, a sisal wheel on a car polishing motor, with black cutting compound.  Some heavy pressure is needed to get the results shown, but no big deal.  The polisher was loaded up, but didn't really complain much.  Shine is NOT chromelike.  Like OEM level of shine.  

P1020637 by nessism , on Flickr

Ed that is why I commented ref Clay's polisher - my bench grinder set-up "stalls" if you lean into it too hard

Yes Wookie, i have two machines, one smaller like Yours and one twice the size. But note if one has to "lean" into it too hard then you might suspect your rouge. Rouge can/will dry-out and become ineffective/flakey. It's the creamy consistency of the rouge that plays a huge part of efficacy. It's this material doing the work not the wheel itself, renew on wheel often. Buy quality stuff, not those discount bars. Makes it as easy as possible.   

When my old buffer failed I bought this Jet variable speed buffer for my dedicated buffing room. Best investment I have made. Has a slow enough speed to polish plastic if needed.