Explanation of hot dip galvanisation

The information you need is available from the American Galvanizers Association (www.galvanizeit.org). Also search this forum for previous discussions related to HDG. There have been several.

Bluestone has given great advice.

Cleaning prior to process is essential. The hot dip process is more sensitive to the preliminary cleaning than it is to the deposition procedures.Your choice of alkaline cleaning, Best for oily soils on product; mineral acid cleaning Sulphuric or hydrochloric, Best for removal of oxide soils; and anodic or cathodic electrocleaning. Or combination of the above.

So my question is why hot dip for pipe? HEat requirements would seem to make electro deposited a much lower cost choice.

Heat loss from zinc bath= 5000 Btu. ft^2/ hour;

heat needed to raise product temp approx 110,000Btu / 1000# of steel;

Plus heat needed to melt zinc

MEasurement of coating thickness - make sample section mounts and examine under microscope.

How ensure uniformity of coating thickness? How do you expect to apply coating to product. Its not like you will be pulling a mile long strand of wire through at a given rate.

Again. Why hot dip?

milo