jsmarshall
Aerospace
- Mar 18, 2005
- 1
A customer complained that some anodized parts (type 2 class 1 mil a 8625) were bleeding yellow coloring into their rinse tanks (tap water).
We received the parts and replicated the results by submerging them in warm tap water. The plating company (who we'll call "BM") reworked the sodium dichromate seal and split the cost with us but could or would not adequately explain the problem.
The parts continued to bleed in tap water and our customer requested that the plating company soak the pieces until they cease bleeding.
We tested older lots and other parts and found that they all bled to some degree into tap water.
The customer is now happy but I'm still curious. Is it normal for the sodium dichromate seal to bleed into tap water? If you soak the pieces, will the seal completely bleed away? What chemical is actually bleeding into the water? Can the seal come off by mere human contact?
Thanks,
Jason Marshall
We received the parts and replicated the results by submerging them in warm tap water. The plating company (who we'll call "BM") reworked the sodium dichromate seal and split the cost with us but could or would not adequately explain the problem.
The parts continued to bleed in tap water and our customer requested that the plating company soak the pieces until they cease bleeding.
We tested older lots and other parts and found that they all bled to some degree into tap water.
The customer is now happy but I'm still curious. Is it normal for the sodium dichromate seal to bleed into tap water? If you soak the pieces, will the seal completely bleed away? What chemical is actually bleeding into the water? Can the seal come off by mere human contact?
Thanks,
Jason Marshall