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  for Metal Finishing since 1989
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Prepaint cleaning-heavy equipment

2007

We are cleaning heavy steel with caustic detergent. Rinsing with city water (very hard-400ppm hardness, 140 ppm chlorides)
post drying, we prime and paint, we have been experiencing some paint flaking.
could this be due to poor quality water rinse?

Rick kuchma
paint shop - London,Ontario, Canada

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If by flaking you mean poor adhesion, you're probably on the right track. Salts (particularly hard water salts) will do a number on adhesion.

I suggest you try rinsing some parts with "good" water and testing the adhesion. If that is your problem, you'll probably need to install a DI system or at least a softener. If cost or flow rate is an issue, consider doing the majority of rinsing with your hard water followed by a halo rinse with "good" water to remove the remaining salts.

Christian M. Restifo
- Pittsburgh, Pennsylvania
2007