End Cap Porosity & Surface Finish Flaws

Symptom / Description:

● Microscopic gas permeation directly through the solid aluminum or steel top/bottom plates, or early surface pitting, flaking, and oxidation.

Root Cause (Substandard Manufacturing):

● Low-grade sand-cast aluminum containing internal shrinkage cavities and porosity blowholes, or cheap surface finishing (thin non-anodized coating or poor electrophoretic paint failing salt-spray standards).

Consequence:

● Unlocatable body leakage through solid metal; rapid structural corrosion and fastener seizure within one winter road-salt season.

QC / Standard:

● Helium mass spectrometer leak test on raw end caps; ASTM B117 salt spray corrosion test ≥ 96 hours.