Oops!
150f on the ultrasounders,. and 100c on the oven. Embarrassing!
On Mon, Jan 14, 2019 at 9:20 AM Henry Vanderbilt <hvanderbilt@xxxxxxxxxxxxxx>
wrote:
Sealed pressurized ultrasonic cleaners? Or is 150C perhaps something else?
On 1/14/2019 10:11 AM, Michael Clive wrote:
Standard when I was at SpaceX:
Three ultrasonic cleaners
One with brulin
Then ipa
Then di water
20mins each at 150c
Then vacuum oven at 100c
On Sun, Jan 13, 2019, 10:42 PM Stefan Powell <stefan@xxxxxxxxxxxxxxxxx
wrote:
I can only speak from my experience. Al 6061 in 20:1 solution (from 8g/L
Sodium Hydroxide) doesn't produce tangible etching but is effective at
cleaning light oil and grease. IPA would also be effective as others has
suggested although we avoided it as we were more worried about flammable
vapours hiding in welds and internal printed structures etc where we could
not effectively get to with compressed air.
Stefan
On 14/01/2019 12:43 PM, Terry McCreary wrote:
Troy is correct, both acid and alkali will etch the aluminum at the very
least. As a kid I discovered that aluminum scraps plus alkaline drain
cleaner (lye) made all the hydrogen I needed. :-) Good bagels are boiled
in a sodium hydroxide solution (food grade poison...), but in a stainless
steel pot, as an aluminum pot will give you gray, metallic-tasting bagels.
As a chem prof for 35+ years, any acetone other than reagent grade may
well leave residue. FWIW 91% IPA is now readily available in most
grocery/drugstores in the US. Follow that with a little (more expensive)
99% IPA and Bob's your uncle.
Best -- Terry
On 1/13/2019 4:16 PM, Troy Prideaux wrote:
I would’ve thought that using an alkaline degreaser on aluminium/aluminum
parts would be no-no irrespective of what was processed previously with the
solution.
Troy
Random tips:
If using an alkaline degreaser, do not clean aluminium parts after having
cleaned copper (or brass) parts in the same solution. It will corrode them.
Another simple test for oils on Stainless parts was that distilled water
would no longer form a meniscus.
Stefan
On 14/01/2019 6:44 AM, Brett Coles wrote:
I have a few questions about oxygen cleaning, and since I want to keep
all my limbs, decided I would run what we have so far by you. The main
concern we have is with drying the parts. The NASA document "SAFETY
STANDARD FOR
OXYGEN AND OXYGEN SYSTEMS" says to dry the parts using a volatile
hydrophillic solvent. Acetone is both of those, but we are concerned it
will leave residue that is flammable. I would rather not have our oxygen
cleaning process leave a hydrocarbon film on our "cleaned" parts. Is
Acetone ok? If it isn't, I think we'll just use 99% IPA.
Here's our process as it currently stands:
0) Clean any major grime with dish soap and a stiff brush
1) Ultrasonic cleaning at 65 F for 40 minutes in degreaser solution.
2) Flip parts and repeat.
3) Rinse with fresh distilled water.
4) Wash in clean white vinegar (Suggested by a medical oxygen site)
5) Rinse twice with fresh distilled water
6) Soak for 5-10 minutes in clean Acetone.
7) Allow to air dry
8) Inspect parts under UV light
9) Bag parts and store in clean container.
If there's anything with this process we need to change, I appreciate
your feedback.
I hope you are all having a wonderful new year!
--
Brett J. Coles
--
Dr. Terry McCreary
Professor Emeritus
Murray State University
Murray KY 42071