I'd have said the the top one was Zintec as well.
If no one has pointed it out to you yet... Welding something galvanized/Zinc coated is *bad* from a health perspective. Ensure you weld in a well ventilated area and with fume protection.
Metal fume fever - Wikipedia
en.wikipedia.org
Welding fume: protect your workers - Overview - HSE
All welding fume can cause lung cancer and can also cause asthma and other health conditions so you must put controls in place.
www.hse.gov.uk
EDIT: Although arguably you should take precautions during "mere" mild steel welding as well https://www.hse.gov.uk/safetybulletins/mild-steel-welding-fume.htm