Topic: Bleedout from plugged holes

We run a sulfuric anodize line around 65F and have been experiencing acid bleed-out from plugged, blind holes after the parts have been dyed black.  We have tried new plugs, both silicone and neoprene, plugged the holes really well, and still get a similar result.  Has anyone else experienced this kind of problem?  Could the seal be compromised in going from a warm ambient temp to a cooler anodize bath, and then have the acid expand once in the heated dye and seal?  Any suggestions?


Re: Bleedout from plugged holes

The hot dye or seal may be creating air pressure breaking the seal of the plug and leading to the bleedout.  Try filling the blind hole with water before pluging it.