Why the end of the aluminum coil will have a yellow spot?
Without coolant processing one, to see if there is no stain, so you can engage in removal of cooling liquid is not interference. Blank surface should have a layer of alumina film processing, heat, such conditions should make the cooling liquid and the alkaline layer friction reaction
The reason may be that the manufacturer is not cleaned, and must be carefully cleaned before coating, or there may be paint fall off phenomenon.
The reason may be that the manufacturer is not cleaned, and must be carefully cleaned before coating, or there may be paint fall off phenomenon.
