Careclean Pickling Paste

Careclean Pickling Paste is a colorless paste for treatment of corroded, heated or welded austenitic stainless steel surfaces or welding seams. Careclean Pickling Paste contains nitric and hydrofluoric acid.

Careclean Pickling Paste is easy to apply due to its gelly nature, even on vertical welding seams and surfaces.

Careclean Pickling Paste is used for pickling of welding seams and surfaces of austenitic stainless steel in any kind of construction, such as: tanks, pipes, frames, etc. Metals other than austenitic stainless steel will be corroded by the strong pickling effect of the product. Nickel, nickel-alloys and copper-nickel-alloys may also be pickled with Careclean Pickling Paste (always test first!).

The surfaces should be pre-cleaned with an alkali waterbased degreaser as: Careclean GP Enviro or Multiclean. After pre-cleaning rinse with plenty of freshwater. Allow the surface to dry.

Please read the security instructions before you start pickling. During storage the paste may become partially liquid. Mix the Careclean Pickling Paste, using a plastic or wooden stirring rod.

Brush the paste on the surfaces and welds in a closed thick layer, with an acid resistant brush. After brushing, clean the brush thoroughly with freshwater and allow to dry. The Careclean Pickling Paste is applied at temperatures from 10 to 25 ˚C.

The product should not be applied in bright sunlight or windy conditions. Allow the pickling paste to act for 15 - 60 minutes on austenitic stainless steel, 5 - 20 minutes on nickel, nickel-alloys and copper-nickel-alloys. In case pickling has not been sufficient, then rinse and re-pickle.

For a temperature change of 10 ˚C up or down from 20 ˚C , the pickling activity and thus the pickling time changes roughly by a factor two. Normally it is sufficient to let the Careclean Pickling Paste act for the given time without further mechanical action. In case the welds are uneven, it may be necessary to rub the welds with a Scotch Brite pad.

The Pickling Paste should still be active.

Remaining Pickling Paste must be removed completely by thoroughly rinsing. Primarily, remaining paste can be removed with rags or tissues. Rinsing should be done with a high pressure cold water jet of at least 50-60 bar. If a high pressure water jet is not available, rinsing with a water hose assisted by brushing or rubbing with a Scotch Brite pad.

Nickel, its alloys and copper-nickel alloys have to be rinsed and cleaned thoroughly after pickling. The chloride contents of the rinsing water should be as low as possible. If possible, use demineralized water.

A protective chromium oxide layer will be formed on the austenitic stainless steel only if oxidizing conditions are present. For example during long term rinsing with cold water (below 25 ˚C) or during storage in the open air. Under these circumstances the stainless steel automatically passivates.

The time for passivation has to be 24 hours as minimum. In case there is lack of time we recommend passivation with Careclean Passivation Liquid, particularly if the stainless steel is exposed to corrosive conditions soon after pickling.

Good results are obtained if the object is sprayed/brushed with Careclean Passivation Liquid immediately after it has been well rinsed. Five minutes after applying Passivation Liquid rinse with plenty of DI water.

Careclean Pickling Paste contains nitric acid and hydrofluoric acid. It is extremely dangerous and when using Careclean Pickling Paste all necessary personal protection measurements must be taken.

For detailed information on safety and health, please refer to the Material Safety Data Sheet MSDS and/or product label.