Polishing!

[Strega]

Has anyone here ever polished (as in bare aluminum) an aircraft that had once been painted?

I think it will be a huge undertaking, but my friend seems to think otherwise.

[HS-748 2A]

I have had pretty good luck by paint stripping with Turco - as many times as it takes to get rid of paint and primer, then go at it with a clean buffing wheel and Autosol polish.

Keep the wheel from 'leading up' - Wash it when ever it seems plugged, dry it or have another clean dry one handy before going at it again.

Foam or a wool wheel. Wool is abit more abrasive and better for cutting but foam gives a higher end final result.

After stripping, there may be some slight paint / primer residue left but the wool wheel will take it off with some elbow grease.

Bear in mind, the alcladding and thus corosion protection is probably compromised by all that buffing. Far from ideal.

It will depend too, if the surface was ever etched - like scuffed with scotch brite before the paint was applied. If so, you're probably not going to be able to bring that one back.

Good Luck,

48

[iflyforpie]

It can be done.





It takes a lot of abrasive action to totally strip the Alclad off. You probably will never get it to a mirror finish like the aircraft in the Breitling ads but certainly passable for the average flight line. You will have to live with any scratches, dings, and dents beneath the current finish.

But it will take a lot of work and it will fade very quickly; especially if the aircraft is outdoors.

[black hole]

Right after the paint stripping go at it with SOS. The soap is a lubricant and leaves a near polished finish, followed by a good aluminum polish.

BH

[HS-748 2A]

Right after the paint stripping go at it with SOS. The soap is a lubricant and leaves a near polished finish, followed by a good aluminum polish.

BH

You couldn't possibly mean the steel-wool SOS do you BH?

That would be the biggest fauxpas I've ever heard of.

[iflyforpie]

Right after the paint stripping go at it with SOS. The soap is a lubricant and leaves a near polished finish, followed by a good aluminum polish.

BH

You couldn't possibly mean the steel-wool SOS do you BH?

That would be the biggest fauxpas I've ever heard of.

+1

[Hedley]

Contrary to what other people here may say, it is REALLY EASY
to wear through the alclad, and then you're screwed - it will
never look the same, polished.

On the bright side (sorry) the aircraft gets a lot lighter without
all that paint. You'd be surprised how much it weighs!

P.S. Bare aluminum is insane in the presence of any salt,
on the coast. If you must temporarily take an aircraft with
polished aluminum into salt, wipe it down with corrosion-X
which will make a horrible, smeary mess, but after you get
away from the salt, it will come off easily with mineral spirits.

[black hole]

OH: And why not steel wool or SOS? I gotta here this!

BH

[HS-748 2A]

OH: And why not steel wool or SOS? I gotta here this!

BH

OK B.H. - I thought from some of your earlier posts, perhaps you were an AME. You have cleared the air on that one.

The term is Dissimilar Metals Corrosion

About day three of tech school, would-be AME's are introduced to the basics of metalurgy.

One of the most basic considerations in aircraft maintenance is to never put two or more metals in contact with one another if they are far apart on the Galvanic Scale.

If two dissimilar metals are in contact with each other with an electrolyte present, then the metal which is less noble, or more anodic, will start to corrode.

This is why aircraft bolts are cadmuim plated and also why corrosion inhibitors like Tecktil and Mastinox are usually employed between mating surfaces of dissimilar metals.

If you were to 'polish' your airplane with steel wool, absolutely gauranteed, you will have embedded steel filings into your aluminum skin.

Expose that now to salt air or moisure of any kind and the skin of your airplane is now a battery. Perfect.

Best case senario, it gets dull right away and that's it.

Worst case senario, steel particles mixed with the aluminum grindings and combined with the 'soap' from the SOS pads makes its way into the skin laps and bingo; in a couple years, you're into replacing skin or potentialy even a stringer.

I could go on as there are many considerations when using abrasives of any sort on airplanes but if you are intested you will research that yourself and I highly recomend you do, particularilly as you indicate you have done this and it works so well...

Regards,

48

http://en.wikipedia.org/wiki/Galvanic_corrosion

[Hedley]

Free advice: instead of physically abrading the paint
off, consider some of the new, highly effective chemical
paint strippers on the market today.

Just be sure to get it all off, esp in the corners and seams.

Once the alcad is bare, then you can begin the polishing
process.

And no, you don't need steel wool for that, either!

[iflyforpie]

In addition to galvanic corrosion, steel wool is highly abrasive. Better to use scotchbrite or something similar that won't easily damage the soft aluminum.

[HS-748 2A]

In addition to galvanic corrosion, steel wool is highly abrasive. Better to use scotchbrite or something similar that won't easily damage the soft aluminum.

Scotch Brite yes, and at that it should be marroon in colour which uses aluminum oxide as the abrasive.

Grey Scotch Brite uses silicon carbide as the abrasive. Not conducive to work with aluminum.

[iflyforpie]

In addition to galvanic corrosion, steel wool is highly abrasive. Better to use scotchbrite or something similar that won't easily damage the soft aluminum.

Scotch Brite yes, and at that it should be marroon in colour which uses aluminum oxide as the abrasive.

Grey Scotch Brite uses silicon carbide as the abrasive. Not conducive to work with aluminum.

Learn something new every day. I always use maroon because that's what has always been in every shop I've worked in and now I know why.

[Strega]

Thanks

The reason we want to polish is excactly what hedley mentioned, to reduce weight!


FYI dont use scrotchbrite on ANY engine components withought being sure all of the "fuzz" has been washed away, the silicone carbide and or alum oxide particles will find their way into the soft friction bearing shells, and act as little cutting tools against the bit it is supporting.


Any idea how long a plane such as an RV-8 would take? from paint till shine?

[black hole]

The point I was trying to make: is that the SOS Extra fine steel wool with the soap as a lubricant polishes the aluminum to a pretty decent shine.BUT THAT IT NEEDS TO BE FINISHED WITH AN APROPRIATE POLISH, thereby removing any residue.

[HS-748 2A]

The point I was trying to make: is that the SOS Extra fine steel wool with the soap as a lubricant polishes the aluminum to a pretty decent shine.BUT THAT IT NEEDS TO BE FINISHED WITH AN APROPRIATE POLISH, thereby removing any residue.

Worst case senario, steel particles mixed with the aluminum grindings and combined with the 'soap' from the SOS pads makes its way into the skin laps and bingo; in a couple years, you're into replacing skin or potentialy even a stringer.

Do whatever you want B.H., just be sure to let a would-be buyer know you do that to your airplane and don't ever do it to mine.

48

[iflyforpie]

Boeing is really strict about what they let touch the bare metal. Used to be that scrapers made from phenolics or old windows was good enough but now they make scrapers out of a special material to prevent damage to the skin.