Acid etching/washing questions

[Jason Puckett]

I acid and stone washed my first blade today. Started with a cheap blade, specifically a small honey badger. Pretty pleased with the results, but had some questions.

I'm using ferric chloride to acid wash. I read somewhere that after doing so, the blades are not food safe. Is this true? If so, can someone give me a high school level explanation of why?

Does acid etching/washing affect the corrosion resistance of the steel at all? If I etch a stainless like S35VN do I need to start treating it like D2 to prevent rust?

Finally (I think), how does sanding the blade before etching affect the finish? I never thought about trying it, but someone asked me what grit I sanded to before I etched, which made me think it is sort of a standard step that I missed.

Here's pics of my results if you're interested:

I overdid it with the nail polish around the pivot, or maybe the knife wasn't submerged enough, not sure which. I've got a taller, narrower container I'm going to move the ferric chloride to so that should help that without having to buy more.

Pic doesn't show the stone wash well, but I'm happy with it. I think I went too dark, this was 10 minutes, so I think I'll aim for eight next time.

 

[Bill DeShivs]

If you clean the blade, it will be food safe.

 

[Jason Puckett]

If you clean the blade, it will be food safe.

Great, thanks!

 

[Heartlander]

If you clean the blade, it will be food safe.

I could be wrong but I think the food safe thing relates to the pores created in the metal by the etching, potentially holding food particulates and bacteria. Of course, if you cleaned it thoroughly that should not really be a problem.