O/T Cleaning Alumium

[jspangler]

Hi

Anyone got any secret sauce used to clean aluminum parts after machining and/or welding?

 

Thanks

 

John

[Lars Christensen]

We are running a production job here were the parts gets cleaned in a dishwasher with some Alu-part cleaner bought from MSC.

 

Lars

[Lars Christensen]

it is called GBD 8007 and is made by Global

[Brendan P]

Believe it or not,I have used the (Boraxo type) hand soap they have in the wash up room and it has worked great!

[Teh Bear without Brains kinda idiot]

+1000 to Brendan !

Me too .

[chris m]

We used some stuff called Alconox [i think] at my last shop that was pretty decent

 

C

[Guest CNC Apps Guy 1]

Mothers!

 

Actually we use Simple Green and that seems to work ok for us.

[specv]

Trichlor, scary stuff i know.

[GreggT]

Is this in preparation for anodize or what is the desired final out-come of this cleaning? We do some prep for vacuum applications and normally use z warm Oakite bath and two warm deionized water rinses and then a bake-out.

 

You have asked a loaded question, the final result could require many different scenarios. How clean do you need these parts?

 

I am interested in what everyone else is doing for anodizing prep. I'm not sure it's my shop or if they are all this way but, it seems like the plater we deal with doesn't want to do crap for prep on parts and sometimes I get fingerprints and all sorts of garbage back from them and they are always telling us it's not their fault? Hopefully going to switch platers shortly but for now we're stuck with these yahoos.

[Chris Rizzo]

We've tried a variety of products and process for pre annodizing cleaning, and beleive it or not the best thing has turned out to be DAWN dishsoap! Leaves parts incredibly brite and clean, with obviously NO residue. Almost as good as R-5/brite dip.

[jspangler]

HI

We're not anodizing them, just sending them out. I have tried SImple Green, but it doesn't get all the crud off. I will try the Boraxo, since that stuff seems least likely to get me in trouble.

 

Thanks

 

John

[MetalMarvels]

Simple Green is not a good choice for aircraft grades of aluminum. The military has done plenty of research to show that it can catalyze hydrogen embrittlement and cause corrosion. It will eat an airframe...... Currently it is strictly prohibited for use on military airframes.

 

Makes sense since Simple Green is an alkaline, aqueous-based solution. If not thoroughly rinsed off, the small amounts remaining in crevices will cause corrosion. Aluminum is expecially sensitive to alkaline solutions - mild acids don't bother aluminum much.

[Brendan P]

John,

When I say that I have used the boraxo type of soap,

I don't mean that I fill a sink up with water and pour in the soap and make a bunch of suds.

Rather,I wet the part real good with warm water then put a 1/4 of handful in one of my hands,wet the powder a bit,and with my hand,rub the part vigirously.

This will make the part get that blackish color to the part and soap.

IMO,the blacker the better.

Then rinse very well.

Especially if you have small holes and stuff.

Try not to get your hand prints all over the pc. after.

 

As far as if this is safe for the mtl....

I have no idea.

Hth's

[GreggT]

Gary;

 

Thanks for the info. I think that Oakite is a base? Maybe we should reconsider our process? Maybe an acidic cleaner would be better?

 

Sounds like you have some experience with this can you get more specific? I for one am very interested in understanding what needs to happen to get clean parts and without having long term problems and hopefully with as little effort as possible. Maybe something that could be done in a dish-washer.

 

Thanks

[Fralex_francois]

Where I went to school, they tought us to anodize our parts. before to anodize it we put it in an acid wich remove everything: grease coolant etc... I could get you what type of acid it was...

[Guest CNC Apps Guy 1]

... Hydrochloric...

 

j/k

[GreggT]

That sounds fun James, especially the bellowing clowd of grey smoke that would result.

[Guest CNC Apps Guy 1]

YEP!!!! It woudl be so clean you would not even see it.

 

 

James teh man I loved chemistry class in High School.

[Threept82]

For pre-anodize, dish soap. The plating house will

finish cleaning just prior to the anodize.

[MetalMarvels]

Actually, the military has found that a mild detergent in warm water is the best all-around cleaner for aluminum. Also, you should not use abrasive cleaners like scouring powders, steel wool, or abrasive polishes - they have a bad habit of embedding in the aluminum surface and can even "kill" the anodizing bath (or so my local plater says). He prefers that I stick to the mild detergent and warm water routine since it doesn't cause him any cleaning or plating issues.

 

LUMINOX- A cleaning solution apparently got good marks - http://metal-cleaning.alconox.com/cleaning_aluminum.htm, but it was a bit pricey for the military needs.

 

The mil spec that applies is MIL-PRF-87937A, TYPE I - but all the products that you find won't do much better than good old mild dish washing detergent and water.

 

If you do have an aqueous cleaning system (tank, spray cabinet, etc.) work with your cleaning system manufacturer to point you to an aqueous cleaner/system that will meet all of your needs.

 

By the way - have you ever seen what happens to an aluminum block if they dunk it in the standard cleaning tank with the cast iron blocks? If they leave it in over the weekend - all you get back are the studs and freeze plugs.......the block is just sludge in the bottom of the tank. Saw that happen at a local engine rebuild shop here in the Springs. The owner of the engine block was a little tweaked.

[MetalMarvels]

Was going to edit my previous post - oh well, guess I waited too long.

 

The biggest thing to keep in mind when cleaning aluminum (general cleaning - not cleaning in prep for anodizing) is that you want a neutral to slightly acid cleaning solution (pH of 6 to 7).

 

When you get into some of the stronger acids (pH 4 and up) you have a very limited dwell time and MUST follow the acid etch with a couple of rinse cycles. Depending on the process to follow, hydroflouric acid, hydrochloric acid, sulphuric acid, and phosphoric acids are often used - BUT ONLY as a preparation step for an anodizing or other chemical conversion coating process.

 

And - those acids can be quite hazardous....and hydroflouric should NEVER be used by someone who has not been thoroughly trained in its use and has all the proper equipment. It amazes me that you can actually buy hydroflouric acid on the open market - it is so very nasty.....