[acidrain]

I just finished a large, welded aluminum sealer tank, and after my first heating, the sealer (high temp nickel sealer) turned cloudy.
I previously used SS pots heated directly on a gas burner with no problems what so ever.
I'm wondering if the raw aluminum plate has caused the sealer to turn milky, or could it be the extruded polystyrene insulation?
The rigid pink insulation expanded a bit, which makes me believe it has given off some gasses.
The sealer still seems to work fine, but I'm not trusting it, and my instincts tell me replace it.
Anybody else have this experience?
Just to be clear, I've tried filtering it, but it's not a suspended contaminate.
For reference, you can only see through it about 1 inch, and it seems to have gotten progressively worse.