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Cleaning aluminum

AjaxTheDog

New member
Has anyone had any luck cleaning the mottling off old aluminum parts? I have tried soda blasting, aluminum jelly and polishing compounds with little luck. Parts look cleaner but still have a mottled rather than bright shiny finish which they had when new. I'd like to get as close to that as possible. aluminum.JPG
 
I've never had to deal with that issue so far, but I notice some threads in the Similar Threads pane at the bottom of the screen...maybe there's some ideas there.
 
I can't quite get a good view of the problem. You said soda blasting didn't work. There is more aggressive blasting like with walnut shells. I've also heard about vapor blasting. There is a link in the Opportunities thread where a member was discussing this procedure:

https://forums.bmwmoa.org/showthread.php?82498-Did-somebody-say-quot-Vapor-Blasting-quot

Here are some other vapor blasting discussions:

https://forums.bmwmoa.org/showthread.php?82476-Vapor-Blasting-has-anyone-tried-this

https://forums.bmwmoa.org/showthread.php?87786-Cleaning-up-engine-cases/page3
 
Guess I will have to try the vapor blasting route. A local guy does it for $75 an hour. Hopefully he can tell me what level of success to expect before starting the operation.
 
Vapor blasting, Brook Reams, etc.

Hi there-

I have had great success in utilizing vapor blasting, especially on things like heads and cylinders. The finish looks factory new. The problem, of course, is that it's not always convenient, or practical, for things like an assembled engine case....

Brook Reams gives a really nice overview of his aluminum cleaning practices on his website. The real trick in some of those methods is time. A lot of time....

https://brook.reams.me

Good luck!

ECJ
 
Hi there-

I have had great success in utilizing vapor blasting, especially on things like heads and cylinders. The finish looks factory new. The problem, of course, is that it's not always convenient, or practical, for things like an assembled engine case....

Brook Reams gives a really nice overview of his aluminum cleaning practices on his website. The real trick in some of those methods is time. A lot of time....

https://brook.reams.me

Good luck!

ECJ

Brook Reams Refinishing Techniques/


AutoSol Motorcycle Products
 
Simple Green Aircraft Precision Cleaner

You might want to try Simple Green Aircraft Cleaner. It is designed to clean aluminum on aircraft but not damage plastic or paint. A good friend of mine who restores old BMW bikes says it gives great results. If you look at the reviews of this product at the Amazon link below there are some user photos of results from using this product. I'm going to try it on a /5 I'm refurbishing once it warms up here in a month or two.

https://www.amazon.com/Extreme-Airc...8&sprefix=simple+green+aircraf,aps,229&sr=8-1
 
http://www.chinook-helicopter.com/maintenance/issues/cleaners/cleaners.html

Apparently, Simple Green does not advertise that the Army had to publish multiple stop use bulletins to keep Army Aircraft maintainers and pilots from using it. It was corrosive over time and would weaken and soften magnesium, aluminum, and titanium; basically any of the alloys. If memory serves, we had at least one catastrophic structural failure that was “present and contributing” in the findings to simple green use.

FWIW I have personally seen the damage to metal caused by Simple Green in the 90’s both on my aircraft and my car (mag wheels).
 
http://www.chinook-helicopter.com/maintenance/issues/cleaners/cleaners.html

Apparently, Simple Green does not advertise that the Army had to publish multiple stop use bulletins to keep Army Aircraft maintainers and pilots from using it. It was corrosive over time and would weaken and soften magnesium, aluminum, and titanium; basically any of the alloys. If memory serves, we had at least one catastrophic structural failure that was “present and contributing” in the findings to simple green use.

FWIW I have personally seen the damage to metal caused by Simple Green in the 90’s both on my aircraft and my car (mag wheels).

Reece,
That warning message appears to be very old as it references a crash in 1992. I suspect they are talking about traditional Simple Green because they did not state "Simple Green Precision Aircraft Cleaner" which is this product's name, and I would expect high precision in statements about aircraft maintenance. Simple Green Precision Aircraft cleaner was not introduced until about 2004 from what I can find, so I suspect that it was developed specifically to address any problems with their traditional product in this application. Is there any way you can find out the date of that warning?
 
Reece,
That warning message appears to be very old as it references a crash in 1992. I suspect they are talking about traditional Simple Green because they did not state "Simple Green Precision Aircraft Cleaner" which is this product's name, and I would expect high precision in statements about aircraft maintenance. Simple Green Precision Aircraft cleaner was not introduced until about 2004 from what I can find, so I suspect that it was developed specifically to address any problems with their traditional product in this application. Is there any way you can find out the date of that warning?

P.S. I did see that at the bottom of that linked page it says it was last updated 1/7/2021, but that appears to be for the whole site, not necessarily the Simple Green warning page. But, I sure would like to know how old that warning is, and which Simple Green product it refers to.
 
I have found that when "staining" that resists the regular "cleaning" methods don't achieve the desired results, the "staining" has migrated into the pores of the metal. Industrial methods are needed as the top lays needs to be removed which can sometimes open the pores of the metal to even faster staining, oxidation and discoloration. Copper that has been outside for a while, and cleaned bright, will almost oxidize before your eyes.

I took a quick look and this thread gives a quick overview of metal polishing-

https://www.kmstools.com/blog/metal-polishing-101/

It's important to "seal" the finished product to protect it. Sharkhide metal finish has had some great reviews although is very specific in it's steps on application. The marine industry has been battling this staining/corrosion for ever.

OM
 
http://www.chinook-helicopter.com/maintenance/issues/cleaners/cleaners.html

Apparently, Simple Green does not advertise that the Army had to publish multiple stop use bulletins to keep Army Aircraft maintainers and pilots from using it. It was corrosive over time and would weaken and soften magnesium, aluminum, and titanium; basically any of the alloys. If memory serves, we had at least one catastrophic structural failure that was “present and contributing” in the findings to simple green use.

FWIW I have personally seen the damage to metal caused by Simple Green in the 90’s both on my aircraft and my car (mag wheels).

Was that the Extreme Simple Green made for aluminum?
 
Greg: I was unaware that Simple Green created a new product since the 90’s.

Lee: we were using “original” simple green... that was the culprit.
 
Greg: I was unaware that Simple Green created a new product since the 90’s.

Lee: we were using “original” simple green... that was the culprit.

The Simple Green home page lists many, many products. Unfortunately, they don't list the introduction dates, but I would believe it reasonable that many of them were introduced withing the last 20 years. https://simplegreen.com/products/

A company pretty much has to add new products to remain competitive. Look at all the things WE40 offers. There are three pages at this site: https://www.wd40.com/products/

I used their Purple cleaner to de-grease the rear chain on a Triumph I bought used about five years ago. The bike was 15 years old and from all appearances the chain had been regularly lubed but never cleaned. It was so stiff with old lube that there was a *lot* of resistance to just turning the rear wheel. I used the Purple cleaner (Pro HD) with a chain brush and a lot of work but got it looking and working like new. https://simplegreen.com/products/pro-hd-cleaner-degreaser/
 
Corroded, not "dirty"

Those parts are corroded, not "dirty." You can buff them out (take material off the surface, make it look shiny) but it will require ongoing rubbing to stay bright. This is because structural aluminum often has a thin outer layer more resistant to corrosion than the material under the surface, and once you rub that outer layer off it will be less resistant to corrosion than when new. I am uninformed on what processes BMW uses to increase the corrosion resistance of their aluminum parts, but you can look at "Alclad" and "Annodizing" on Wikipedia to get an idea of how atmospheric corrosion issues are sometimes dealt with industrially with surface treatments.

I have an airplane that came to me with a polished aluminum prop, but required so much rubbing to keep it bright that over time the thickness of the prop was reduced to the point where the prop eventually nearly would not pass inspection. I ended up having it painted.
 
Has anyone used this product?

https://www.por15.com/por-15-cleaner-degreaser

POR-15 Cleaner Degreaser (formerly marine-clean) cleans and degreases in one application without leaving residues, noxious fumes or flammable solvents. No other cleaner works as fast or as well. It makes petroleum-based cleaners almost obsolete because POR-15 Cleaner Degreaser can be diluted with water up to 4 to 10 times its volume while remaining more potent than other cleaners. POR-15 Cleaner Degreaser removes grease, oil, mildew, algae, musty odors, soap films, wax. Use it to clean canvas, vinyl, nylon, holding tanks, grease traps, auto parts and more.

Adhesion is important with most paints but has to be perfect for POR-15 Rust Preventive Coating to achieve its maximum effectiveness. A solvent wipe before painting didn't work with POR-15 Rust Preventive Coating; in the lab we found it did more harm than good by leaving a residue that didn't help with adhesion or appearance. We had to come up with a substance that would clean metal without leaving a residue. What we developed, POR-15 Cleaner Degreaser, contradicts all accepted theories about metal prep products: its water-based, not solvent-based and it cleans without leaving residues. In laboratory adhesion tests, our POR-15 Rust Preventive Coating using POR-15 Cleaner Degreaser first to clean the bare metal far exceeded every other prep product we found in the marketplace.
 
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