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Ted Mooney, P.E. RET
Pine Beach, NJ

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Odd porosity on anodized threads AFTER sealing

Q. I'm type 2 anodizing black and I have been having this problem when sealing this particular part that has threads that are form tapped. It looks as if there are little specs of lice growing off of the threads and this was not there after the dye and rinse cycle. The odd part is that we do not have this problem with any of the other parts that we use form taps on. This is the only part. Yes, I've tested the sealant. The pH is right on the money and I've changed the sealant several times and it does it on the first or 15th run.

61716-1a 61716-1b

I'm hoping someone has run into this. I'm using aluminum racks with titanium hangers for the parts.

Todd Brueckmann
- ASHLAND [Virginia]
August 15, 2024

A. I would guess that there are little voids and/or burrs left from the thread forming. This traps sulfuric acid electrolyte which blooms out over time as white aluminum sulfate

Chris Jurey, Past-President IHAA
Luke Engineering & Mfg. Co. Inc.

Wadsworth, Ohio

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