Chemical Storage issues... seeking advice

[dcurrier]

Hello!

I have been using the Alumiprep-33 / Alodine 1201 to prime the internal parts of my airframe (so far have only completed 90% of my RV-8 empennage kit). So far I have been very happy with the results. Especially when I started using the immersion bath technique. However, I have discovered some issues with storing the chemicals of the bath after the fact. Particularly the Alumiprep-33. My solution is a 1:4 dilution as per the technical bulletin. I had been storing the solution in the plastic jugs that distilled water comes in from Wal-Mart. (Essentially plastic milk jugs). These jugs are marked "2-HDPE" on the bottom. The jugs that the undiluted chemical originally came in are also marked "2-HDPE", but are of a thicker material than the water jugs I was using. I was storing these on the bottom shelf of one of my EAA work tables. A few weeks ago I came into the garage and noticed I was smelling the chemical. When I checked, one of the jugs had formed a pinhole leak in the side and had been dribbling out.
Suction had prevented most of the chemical from leaking out, thankfully.

Thinking I had encountered a random defect in one of the water jugs, I purchased more water jugs and also a couple of Sterilite storage totes (marked "5-PP") to use as a secondary containment vessel. Then I transferred the Alumiprep-33 immersion solution into the new jugs. I put all the jugs inside the Sterilite storage totes and called it a day. Unfortunately, today (after a hot spell where the external temps in the Phoenix, AZ area were between 115 and 120 all week), I noticed the smell again. When I looked I saw that one of the jugs had imploded. The secondary containment held, however. This time after consulting a trusted friend/advisor, I purchased 4 gallons of distilled vinegar (in jugs marked "2-HDPE" and of approximately the same thickness as the original chemical container) and used these to contain the Alumiprep-33 solution. I also purchased additional Sterilite storage totes to use as tertiary containment vessels. A little overkill I know. I have also moved the chemicals to a downstairs closet in the A/C'd part of my house so that the heat won't be an issue. I think a combination of the heat in my garage and the thinness of the water jug containment vessel is what lead to the leaks.

So, I was wondering. Is anyone else using the immersion bath technique with Alumiprep-33 / Alodine 1201? If so, how are you storing the solution after the fact?

Thanks,

[BillL]

The issue is your containers. I have water jugs in my garage and kitchen (distilled) and they will all just become friable and break at any time. Not touch, vibration, nothing. They are not suitable for any longer term storage. Don't know why. Irradiation?

I keep my alodine and alumniprep in 5 gallon containers, old paint/drywall containers. HDPE. No issues yet. At times use rubbermaid HDPE 30 gal tubs for dipping. and they also seem to stand the test of time. Like a garbage container (80 gal).

[fl-mike]

Arizona Tea jugs. They are quite thick for some reason. Work great. Remove the labels!
I've had alodine (mix my own from powder) in some for years.
BTW, keep alodine out of light and use a secondary container (opaque) like you do.