Question on polishing metals (on aircraft)

[g35_coupe]

We frequently polish the "d-rings" or nose caps on aircraft inlets which are made from either stainless steel or aluminum and are uncoated.

We currently wetsand with 400 then 1200 and 2000 (but usually only if aluminum). After wetsanding, we hit them with Mothers Aluminum Polish on a 3" non-DA polisher using 3M Perfect-It wool pads. The end result is pretty good but we still have some scratches left and polishing "trails" or haziness at times. Once the pad is loaded up from working a small section, we use compressed air to blow them out. Current process takes about 1 hr for sanding and about 30-45 mins polishing. I'm not looking for perfection since these nose caps are big and time and money are important. I will by trying to add one more grade of wetordry to eliminate the scratches but wondering what to do about the "trails" and haziness. I have tried some PB SSR 3 on a Cyclo yellow cutting pad but did VERY little against the haze and trails. It wasn't worth the extra time/products for the difference I saw. Any suggestions?

 

[opie_7afe]

why not try the wolfgang metal polishes, they have different grades of polish just like for paint, you might need to use some 0000 steel wool after you 2000 grit or just use 0000 steel wool instead of sanding, or spend more time sanding to make sure all the previous steps sanding scratches are removed. good luck!

 

[forrest@mothers]

A couple of thoughts since you're using our polish:

1) If you still have sanding marks, use 3,000 or so (wet) before doing your polishing.

2) The product you're using really isn't made for use with wool pads, and you don't want to let it run dry. Try using foam (medium) instead and use plenty of product, or work smaller areas, so it doesn't dry out. You should always have a buttery black residue, which should be wiped away with a towel while still wet, not buffed away. Speed is not your friend here - low speed is plenty.

 

[bravozulu]

I worked in Air Operations at FedEx (not Maintenance). Because of the velocities of the air at the inlet, those Nacell trims are hardened.

So don't be shy about the abrasives you use. I know that for buffing the windshields on 747s, the guys in the paint shop used over-the-counter 3M glass polishers. And each pane of glass cost in excess of $15,000. Bugs, dirt, rocks are hitting the front of a jet at 500+ mph. Velocities are even higher near the inlet of a turbine engine, so the materials are hi-tech tough.