Coating Reference Handbook - Hempel

HEMPEL
CHECKPOINT WATER SOLUBLE SALTS P 11b
WHY?
Water-soluble salts are not removed by mechanical surface preparation methods.
Contrary they may be imbedded into the surface.
Water-soluble salts under the paint film will be able to absorb water through the
paint film, osmosis, and this will lead to premature blistering and penetration of
corroson products.
CORRECTIVE ACTIONS:
Salts must be removed by water. Recommend high pressure fresh water hosing
or water hosing at the same time using stiff brushes. Always from up towards
down.
PREVENTIVE ACTIONS:
Against salts advice to store under shelter or to establish a procedure of fresh
water cleaning before material is taken into manufacture.
HOW TO DETECT:
Salts are difficult to detect. Usually extended exposure to marine or industrial
outdoors environment will mean salt contamination.
Bresle sampling + Conductivity measurement according to either
The HEMPEL Method or alternatively ISO 8502-6:
Soluble salts on the surface are dissolved in distilled water, using a Bresle
Sampler.
The amount of dissolved salts are measured by a Conductivity Gauge.
For use consult page R6c (HEMPEL Method) or ISO 8502-6.
For CARGO TANK COATINGS and other critical jobs always consult the
specification and page R 6 a-c.
INSPP11b, ed1 05/03/03 EMi