I've been having issues with powdercoating on top of zinc plated mild steel sometimes. Have issues like small dots visible instead of a smooth texture.

It looks like how a zit or pimple looks on the skin.

After zinc plating, it is pre heated for 15 mins at 150 degrees celsius. Then sand it with some 80 no sandpaper. Finally powder coat it and cure it again for 20 mins.

Amy inputs would be appreciated. Thanks guys.

Attached some images below:

https://cubeupload.com/im/Temporalator/Screenshot2024061610.jpg

https://cubeupload.com/im/Temporalator/18bScreenshot2024061610.jpg

Edit:
Hi guys, I posted recently about facing issues with powdercoating zinc plated mild steel. And I'm really thankful for all the responses I got. The zit like small dots I had last time were pretty much solved with outgassing.

I am now facing another issue where the product has sort of tiny indents or pinholes. I can get my nail in them. Shared some photos below. If you guys could shed some light on what these are and why this is happening despite outgassing, it would be great.

Currently outgassing the parts at 250 degrees celsius for 30 mins. The curing temperature after that is 200 degrees celsius for 20 mins.

https://cubeupload.com/im/Temporalator/WhatsAppImage2024062.jpeg

https://cubeupload.com/im/Temporalator/f15WhatsAppImage2024062.jpeg

https://cubeupload.com/im/Temporalator/15eWhatsAppImage2024062.jpeg

https://cubeupload.com/im/Temporalator/9caWhatsAppImage2024062.jpeg

Thanks everyone.

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