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ZEKER ZINK Handbook

CHECKLIST PROPER AND SAFE GALVANIZING

Check 1 - openings for venting and outlet
Check 1 - openings for venting and outlet

1a: Pay attention to the size of inlet and outlet openings and vent holes (see table at check 6).
1b: Provide armor pieces, stiffeners, head and foot plates with recesses.
1c: BLIND holes is highly discouraged. Enclosed areas and moisture can lead to explosions during galvanizing and are therefore a risk to galvanizing workers. If non-inspectable (blind) holes are installed, proof of this must be provided. Consult your galvanizing company for the proper location of holes.
1d: Avoid small spaces between overflowing plates and profiles. If there is no other way, provide vent holes
if contact area ≥ 100 cm2.
1e: Pay attention to recesses in any bulkheads present.
1f: Tanks and vessels : provide blow-out openings of at least Ø 100 mm per 500 liter capacity. Will you galvanize vessels and heat exchangers externally or weld baffles/plates into the tank? Consult and inform your galvanizing company! In doubt? Ask your galvanizing company about size, number and location of the outflow openings.

Check 2 - marking the sample
Check 2 - marking the sample
  • Note the requirements in standard EN 1090-2 (if applicable).
  • Mark the sample by:
    • deep impacts in the material, or
    • a welding caterpillar, or
    • metal markers affixed with iron wire
      (not aluminum)
Check 3 - distortions
Check 3 - distortions
  • Design symmetry.
  • Avoid large differences in steel thickness.
  • Maintain proper welding sequence.
  • Limit guide stresses and stresses due to cold deformation
    to the maximum.
  • Thin sheet steel must be allowed to expand evenly in the zinc bath
    .
  • Apply set reinforcements in the plate surface
Check 4 - moving parts
Check 4 - moving parts

Provide at least 2 mm extra space for hinges, latches and other moving parts (depending on material thickness).

Check 5 - avoid hollow spaces
Check 5 - avoid hollow spaces

Fluid and/or air in cavities can cause deformation or explosions during the
galvanizing process. This can lead
to hazardous situations for employees and damage to
facilities.

Check 6 - holes and cutouts
Check 6 - holes and cutouts
  • Drill holes for bolts at least 1.5 mm larger than normal.
  • After countersinking, tap threaded holes.
  • Provide suspension holes or lifting eyes as requested by the galvanizing company.
  • Dark colored parts in the drawing indicate the holes on the diagonal side.
  • The dimensions for the cutouts refer to the length of the rectangle side.
Check 7 - welded joints
Check 7 - welded joints
  • Remove welding slag and spatter.
  • Use only silicone-free welding spray and clean the surface after welding.
  • Use low-silicon welding wire and/or welding electrodes to avoid
    worked-up welds after galvanizing.
  • Keep welds tightly closed and free of craters to prevent rust water.

Check 8 – condition of material to be galvanized

Is your steel suitable for hot-dip galvanizing? What are your requirements for appearance and duration of protection? Consult your steel supplier and galvanizing company. Also read the requirements in standard EN ISO 14713-1 and EN ISO 14713-2 .

  • Limited rusting is allowed.
  • Remove large amounts of grease or oil. Remove all surface contaminants that are not compatible with hot-dip galvanizing. Cutting, punching, and drilling oils are not a problem.
  • Remove paint and varnish beforehand.
  • Remove sticker residue and adhesive residue well (otherwise there is a risk of non-galvanized spots). Avoid combination of old and new steel (prevents differences in visual appearance after galvanizing).
  • Know the dimensions of the zinc bath and adjust the design accordingly.

Check 9 – Threaded products

Use only hot-dipped galvanized bolts when mounting hot-dipped galvanized structures. After galvanizing, thread the nut so that the bolts fit perfectly. No zinc coating in the threads of the nut does not affect corrosion resistance; the zinc coating on the bolt protects the nut.