Metal Shavings from Mill Rollers

[flbrewer1]

I noticed today after cleaning out my mash tun that I had some shiny metal bits below the bottom of the screen. This has happened before (previously with the Barley Crusher, now while using the Monster Mill) and I didn't see anything make it to the final product.

Has anyone ever seen any metal at this point in the process? I can only assume it's from the mill. The volume of shavings is minor and the particles are extremely small. Thoughts?

*FWIW, last time this happened I went so far as to put rare earth magnets on the plastic fermenter and nothing stuck to it.

After a close look at the rollers I saw the tiny flakes of steel that were coming off (pictures below). When I placed some rare earth magnets over various parts of the rollers, I could see the flakes raise off the rollers. I am really surprised at how much is coming off the rollers. The more I run the magnets over it, the more comes off. I can't imagine any amount of grain would be able to take these shavings off. The fact that this has happened to me with two different mills (assuming two different manufacturers) leads me to believe it's a widespread issue. Perhaps people just aren't catching this or aren't looking?

I'm going to hit it with a wire brush and see if I can't fix this!
http://imgur.com/pAp5x2y

http://imgur.com/LOcTHyX

 

[ong]

You didn't by any chance close the gap to the point where the rollers are touching, did you?

 

[flbrewer1]

Nope, they are set to factory.

 

[stpug]

When I got my mill I ran through some rice on a tight gap setting. This eliminated most of those manufacturing shavings/chads. The remaining worked off over the course of a few more regular batches. The knurls are completely shaving-/chad-free since then. I think it's pretty common on freshly knurled rollers and just something folks should look to clean up on their end.

 

[IslandLizard]

When I got my mill I ran through some rice on a tight gap setting. This eliminated most of those manufacturing shavings/chads. The remaining worked off over the course of a few more regular batches. The knurls are completely shaving-/chad-free since then. I think it's pretty common on freshly knurled rollers and just something folks should look to clean up on their end.

Yes, rice is a good scrubber. It also removes machining oils and factory pitch. Ran it through a few times. What came out was pretty gray.

Warning: This is a Goggles-ON exercise!

 

[Rev2010]

For initial use I just took all my small leftover amounts of grain and ran it through, was a few pounds. Then I used a can of air and blew off the rollers then used a brush and brushed them off. Since then I don't think the slightest about it. I figure any particles that may be present from wear are too tiny to be of concern and they should be held back by the grain bed. Even if they were to make it through the mash and into the kettle I strain my hop trub and anything else would settle into the trub in the fermenter. Don't recall ever reading of anyone being harmed from a tiny flake of metal from a grain mill so I wouldn't worry about it. Only when the mill is brand new.


Rev.

 

[bethebrew]

You should probably be far worried about the metals and other contaminants in your water than a few flakes from the grinder. That and the BPA in plastic mash tuns that leaches out quite well at 150 f. Theoretically, of course, you may have perfect water.

I hit a rock using the monster mill yesterday, and it barely blinked. The barley crusher would have screeched and whined...

 

[augiedoggy]

You should probably be far worried about the metals and other contaminants in your water than a few flakes from the grinder. That and the BPA in plastic mash tuns that leaches out quite well at 150 f. Theoretically, of course, you may have perfect water.

I hit a rock using the monster mill yesterday, and it barely blinked. The barley crusher would have screeched and whined...

I was told the plastic won't leach until temps of 170 are reached... This is why most coolers are only food safe till 170 degrees.. Can you share your source for info? I may have been misinformed but my info came from a thread here where someone contacted a couple cooler manufacturers and shared their responses.
I no longer use a cooler myself but this is good info to know.

 

[flbrewer1]

I was told the plastic won't leach until temps of 170 are reached... This is why most coolers are only food safe till 170 degrees.. Can you share your source for info? I may have been misinformed but my info came from a thread here where someone contacted a couple cooler manufacturers and shared their responses.
I no longer use a cooler myself but this is good info to know.

Hijack threads much?

 

[augiedoggy]

Sorry... Just responding to another comment made but yes it was off topic... Didn't realize you were still looking for another answer to your questions. No one had posted in days so I mistakenly though you had accepted all the responses you got and moved on.

 

[flbrewer1]

sorry... Just responding to another comment made but yes it was off topic... Didn't realize you were still looking for another answer to your questions. No one had posted in days so i mistakenly though you had accepted all the responses you got and moved on.

shame, shame, shame

 

[Fold Peter]

I have the same problem with a countertop mill. I ordered it online, complained to the seller and they paid some back but they were not admitting that this thing wasn't food safe. The amount of shavings that comes off is quite notable, it is more like dust then shavings in fact, and I'm sure it is very unhealthy. I'd rather eat larger peaces of metal then these extremely small particles, but neither of the ideally. I hit the thing with a dremel to see if I can smooth the surface to a point where it is no longer grinding itself but that wasnt sucessful. Now I am thinking of replacing the moving parts to wooden parts, that might help, altough I am not sure.

 

[IslandLizard]

I have the same problem with a countertop mill. I ordered it online, complained to the seller and they paid some back but they were not admitting that this thing wasn't food safe. The amount of shavings that comes off is quite notable, it is more like dust then shavings in fact, and I'm sure it is very unhealthy. I'd rather eat larger peaces of metal then these extremely small particles, but neither of the ideally. I hit the thing with a dremel to see if I can smooth the surface to a point where it is no longer grinding itself but that wasnt sucessful. Now I am thinking of replacing the moving parts to wooden parts, that might help, altough I am not sure.

Is this a roller mill? Are the metal flakes perhaps residue from machining, especially the knurling on the roller surfaces?
You should always run a few pounds of old grain or rice through mills before putting them into regular service. That will remove any debris and machining oils and dirt.

Also make sure the rollers don't touch each other anywhere.

 

[augiedoggy]

both of my mills are from the same manufacturer (cereal killer and kegco) but I dont recall this issues on either mill. I wonder if the rollers are made or treated differently depending on mill maker to contribute to this. I know the barley crushers rollers are not hardened (well?) as thats the #1 failure with them but im surprised to hear this has been an issue on some MM mills.