When we talk about galvanized finish, basically we have two choices in mind, one is Hot Dipped Galvanized (HDG), and the other Electro Galvanized also known as Cold Galvanized.
The easy telling difference between HDG and Electro Galvanized is the cost, HDG is about 5 times than Electro galvanized.
And another difference is the galvanized surface. If you check the Hot Dipped Galvanized finish, you will find it was not so smooth and nice compared with Electro Galvanized, and even there are lots of “pimples” on the surface of HDG products, and the color of HDG is darker than Electro Galvanized.
We give Acrow Props as example to move on.
Especially when you see the Electro Galvanized finish in the sun, you even can notice the colorful reflecting light from the Electro Galvanized finish, like a colorful mirror reflecting the sun. While the HDG is plain, and not so eye-catching.
Another difference is the thickness of both finish, this is the difference youneed to measure with professional equipment. And the average thickness of Electro Galvanized is about 8μm–10μm, while the thickness of Hot Dipped Galvanized is 80μm–100μm, even thicker, that is why the weight of HDG scaffolding products are Electro galvanized ones.
For example, if Electro galvanized steel prop with max height 3.0m, and weighs 10kgs, while the weight of HDG one is about 10.05kgs, which is 1.05 times than previous one.
So in one word, HDG is better at durability and anti-rust performance than Electro Galvanized, prices will be accordingly higher than Electro Galvanized
Antony – how do you presume that EG cannot be as thick as HDG ?? Moreover it is not the quantity of Zn alone that plays a role – it is also the quality of adhesion of Zn with the steel that is important. More Is not always better – quality beats quantity ! Electro plating is chemical bonding of Zn on steel and it is far better that hot dip. In a nut shell hot dip 10 microns vs EG 10 microns – EG will be better by miles. Let’s compare like to like. In USA pick up truck body is made of EG 80 Gsm.
Politely also wish to point out that Zn 100 micron is actually 780 GSM. You have erred in units of Zn DFT.
Appreciate your read. Thnx. John.