I was just contemplating changing the burrs on my Mazzer Major and retrieved the unused set I have. The packet is open and on inspecting them I notice some spots of rust, not a lot, but enough to make me wonder. I'll attach a picture. My questions are really;

1. Are they OK to use?
2. Should I do anything to them before I do so?
3. How should one store unused, unsealed burrs to prevent them going rusty?

Any advice would be greatly appreciated.

Thanks Dan. I thought it was probably OK but wanted to be sure.

I fully agree with Dan's comment about the fact that any surface rust will be polished away by a few pounds of coffee.

In addition, any corrosion on the cutting edges, even very little and possibly not even visible, would result in blunt edges very fast under the same polishing exercise. After the polishing stage, have a look at the edges of the burrs to see if they are still sharp.

That's all...

So, for the other question, would you want to coat spare burrs in oil to prevent rusting and clean them before installing?

Would coating the burrs w/Dow 111 or similar and then sealing in a ziplock be ok? Any chance of fungal growth if left in a drawer for an extended period of time?

curious, in Ft. Worth.

Dow 111 is a Silicone based lubricant that is chemically resistant (will not oxidise and degrade into nasty stuff) and does not promote fungal growth in itself.

As far as I can tell, Dow 111 is not a fungal inhibitor so it will not prevent fungal growth in a zip-lock, but any surface coated with it, would be protected. But to initiate the fungal growth there would need to be some food in the bag... Just be careful not to put any!

Any carbon steel machined part is typically stored with some kind of moisture displacing, corrosion inhibiting lubricant/compound. There might not have been enough on the above parts. Also I would not assume that the compound used to protect the burrs to be food safe and would season them thoroughly before use.

Hi guys,

try a bag of silica gel thrown in together with the burrs into a zip lock bag. Should 'eat' at least some of the moisture inside the bag and hopefully reduce the amount of rust build up.

I'm guessing that dow 111 would be a pita to clean, so in my opinion it's a nono.

Regards,
dsc.

You can also use a good food safe machine oil to coat the burrs. Use one specifically for food equipment, and it should be fine (and cleanable when you're ready to use the part).