Maskote Zinc Stop-Off


Steel Supply Co. offers Maskote Zinc Stop-Off for Structural and Miscellaneous steel fabricators.Maskote process shown on hooked Anchor Bolt 

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Maskote Zinc Stop-Off steel coatings stop selected sections of steel from being Hot Dip Galvanized

Information and Instructions for Use (click here)

This specially formulated solvent based coating allows covered areas to remain clear of zinc coating while steel is being Hot Dip Galvanized.

Maskote Zinc Stop-Off works effectively on any carbon steel surface; I-Beams, Angle, Channel, Tube, Flats, Rounds, etc. The images to the left focus on the threaded portion of the Anchor Bolts because that is the most critical and difficult application, but this steel coating will work as effectively on any carbon steel being hot dip galvanized.

Maskote is a solvent based steel coating that can withstand the surface preparation fabricated steel goes through prior to being galvanized. Typically, this is three separate acid baths known as De-Greasing, Pickling and Fluxing. Throughout these processes the Maskote coating will remain intact.

The steel is then immersed in the final molten zinc bath. The layer of Maskote Zinc Stop-Off prohibits, "blocks," the active zinc from bonding with the steel substrate. When the steel is removed from the zinc bath and cooled one of two conditions will exist;

  1. Zinc has hardened on the protected area but the underlying Maskote coating has not allowed bonding with the steel. This zinc "crust" can be easily removed by wire brushing, sandpaper, or any suitable method.
  2. Zinc is not present in all or some areas, but instead there is a black ash coating. This is Maskote after it has oxidized. This residue ash coating is removed the same way the un-bonded zinc is in case #1 above, i.e. wire brush, etc.

As shown in the images to the left, hand wire brushing is all that was required to clear any ash residue from the threaded portion of the Anchor Bolts.

The hand brushing process took approximately 1 minute per bolt. (The Anchor Bolts used in this example are 1" diameter with 5" standard UNC-8 threads. The nut shown in the lower images was threaded by hand. No wrenches or power tools of any kind were used.


To learn more about Maskote Zinc Stop-Off and other steel coatings, contact us or request a free quote today.


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