Hi Good Morning. Thanks for the information. Wanted to clarify what is the timing duration for rinsing/fluxing/zinc molten bath ? Can you also provide information on electro galvanizing process ?
She said the metal had to stay in the zinc bath for 10 minutes. Then you can calibrate those other steps for 10 minutes too. If the acid hasn't removed all oxidation within 10 minutes, add some more acid, etc.
Mam from last one year we changed two kettles , two kettle are used only five month each. What is life of kettle ? Why kettle are puncher for what reason ?
Go through this content. You will get the full details. All details cannot be informed in one youtube video. This video was done for students, not for commercial purpose. www.iitk.ac.in/ce/test/IS-codes/is.2629.1985.pdf
Thanks for useful presentation, but i can't tinning copper cos tin is more activity than copper. Also the definition of hot dipping applying for galvanizing only cos there is a reverse relation between metal activity and milting point. Right? ☺
Hello Ravathi mam, its very informative presentation. Thank you! I have a questions. You mentioned that zinc coated utensils should not used for storing food items. But how could i find if a zinc coating done when a utensils i select from store?
You need not worry. Cooking and storage containers are normally coated with tin. It is harmless. When we purchase stainless steel and aluminium vessels, it will never be coated. Zinc coating will be grey in colour like your galvanized iron screws (GI).
The drying or preheating processing before Galvanization is not only to avoid splash but also to avoid thermal expansion/ thermal shock which can cause deformation of the metal component to be dipped
After quenching there is one more process of dipping it in a deoxidation tank so that we can prevent White Rust and White rust is especially likely to form on newly galvanized material. This is because the new zinc coating has not yet had the chance to form the stable oxides, and the hydrogen and the oxygen bond with the pure zinc which forms zinc hydroxide .
I only guess that , there is a post treatment given .the part is quenched in a tank of water and chemicals to form passive layer. In that context may be the above process of deoxidation is not required. I am not sure but its only a guess.
Thanks for your suggestion. I purposefully gave different diagrams for galvanizing and tinning. The diagram for tinning will hold good for both galvanizing and tinning, for the writing exams. But practically in industries, the diagram used for galvanizing is adopted. So, I thought the students should know both. What ever is the diagram, the concept remains the same. The material to be coated should go into each tub. Anyway I am happy that you have expressed your opinion.
