Rebuilding my grain mill

[watermelon83]

I put this together 10 years ago. Some friends from work, machinists, made the roller body from plans that were floating around rec.crafts.homebrewing iirc. Has been up in the attic until today. I didn't get a before shot of the rollers, but they were as bad as the shaft and adjustment knobs.

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[GilaMinumBeer]

A brushed on coating of phosphoric acid (or soak in coca-cola), followed by a water rinse, and a slathering of bar-keepers friend should clean that right up and protect it from future rusting.

 

[blizz81]

A brushed on coating of phosphoric acid (or soak in coca-cola), followed by a water rinse, and a slathering of bar-keepers friend should clean that right up and protect it from future rusting.

Is that all I needed, a coca-cola soak? And to think I went at my rusty rollers with a dremel.

 

[watermelon83]

A brushed on coating of phosphoric acid (or soak in coca-cola), followed by a water rinse, and a slathering of bar-keepers friend should clean that right up and protect it from future rusting.

I have Diet Pepsi and muratic acid, will either of those work?

 

[Mike_kever_kombi]

Most any cola will have phosphoric acid. Just look at ingredients.

I would not use muratic acid on Aluminum.

 

[watermelon83]

They are steel.

 

[GilaMinumBeer]

Is that all I needed, a coca-cola soak? And to think I went at my rusty rollers with a dremel.

I have Diet Pepsi and muratic acid, will either of those work?

H3PO4 is proven to convert Iron Oxide into a water soluable compound, thus removing it. The Oxalic Acid in bar keepers friend will start the process of of repassivating the exposed surface.

Dark soft drinks like coca-cola, and pepsi have phosphoric acid in the mix.

 

[watermelon83]

Okay letting it soak overnight in Diet Pepsi. I think I have some BKF, would BLC work? NM it's not.




Edit: not the same

 

[watermelon83]

Took a peek after 24h in the "rust removing phosphoric acid solution" formally known as Diet Pepsi, it looks good. The rollers are rust free, but I'm working 12'sfor another day so it'll get 48 in solution. I'll snap another picture before the BFK addition so you'll have a good idea how well this worked (guessing very well).

 

[GilaMinumBeer]

Took a peek after 24h in the "rust removing phosphoric acid solution" formally known as Diet Pepsi, it looks good. The rollers are rust free, but I'm working 12'sfor another day so it'll get 48 in solution. I'll snap another picture before the BFK addition so you'll have a good idea how well this worked (guessing very well).

I have every faith the phos in the soda will do the deed given enough time. The trick is getting the assembly rinsed of the sugars, dried, and re-passivated quickly enough to prevent it from rusting again.

 

[watermelon83]

Okay. 48 hours later and......View attachment ImageUploadedByHome Brew1419050026.725564.jpgView attachment ImageUploadedByHome Brew1419050087.475525.jpg

I pulled it out. Used compressed air to dry it, wiped it all down then used two bottles of BKF to re- wet the entire thing. Color me impressed.

Thanks so much for the advice, spot on!!

My wife would hang me by my nuts if she found out I posted pictures of the dirty stove. It's our basement kitchen, my world, my mess. On top of that I've been in the middle of projects so long now It's been to covered by work to any cleaning. Sorry hun!

 

[watermelon83]

Got the base and motor from the attic today. Attached is the 5:1 gearbox I bought off eBay years ago. Yes the motor is open in the back. Yes o understand the danger of a dust explosion. No I don't think it'll ever happen while milling 35lbs of grain. I also do not think it's even within the realm of clear thinking common sense. So if your about to make a comment contrary to my belief, by all means do, but have some science to back it up please.

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[govner1]

I put this together 10 years ago. Some friends from work, machinists, made the roller body from plans that were floating around rec.crafts.homebrewing iirc. Has been up in the attic until today. I didn't get a before shot of the rollers, but they were as bad as the shaft and adjustment knobs.

View attachment 242289View attachment 242290

Jesus! You
Must have one damp attic!

 

[watermelon83]

It's not too bad really, but ten years full summer humidity and exposed steel didn't stand a chance. If I had thought I would ever have brewed again I would have oiled it first.

 

[watermelon83]

Okay, I did some work on the hopper as well. A buddy made it for me and it's very nice. However, neither of us really had any idea what was needed to actually mill grain and I remember the one time I actually test ran this sucker a whole bunch of grain fell through uncrushed. So I had to modify it.

I pilfered some painted steel from the scrap bin at work (with permission) to smooth out the lips on the bottom and direct the grain directly into the roller bite. I also found a roll of special fiber reinforced grain mill tape to cover the rather large holes in the sides.

 

[watermelon83]

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[buttmelon]

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[watermelon83]

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[watermelon83]

Does the crush look okay?

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[IslandLizard]

This looks very coarse. Are those whole kernels, or just empty husks?
Now the stuff on the very bottom looks much finer ground. <== Oops, nvm, that's your glove! Too coarse for my taste.

Regular mash or BIAB? If regular, fly or batch sparge?

Use a feeler gauge or credit card. Start with a 0.032-0.034" gap.

That's one mighty motor / reduction gear you've got there!

 

[watermelon83]

This looks very coarse. Are those whole kernels, or just empty husks?
Now the stuff on the very bottom looks much finer ground.

Use a feeler gauge or credit card. Start with a 0.032-0.034" gap.

That's one mighty motor / reduction gear you've got there!

Those are husks, the majority of the kernels are split into 2-3 pieces. My fiber reinforced grain mill tape needs extended down a bit more a fair amount slid over the edge.

I need to improvise some way of tightning the belt I had it set for a finer crush but the belt slipped. Right now just the weight of the motor and the hinged base plate provide tension.

The motor gearbox combo gives me around 180 rpm I figure. I need to come up with something to run on the other output shaft, it'll make it cooler.

 

[watermelon83]

Well after just two batches I broke down and bought a MM2 with SS rollers. My motor didn't have the torque to get this one going so I hooked it up to a drill. Drill had the torque but my moveable roller has this bad habit of sliding to one side of the mill or the other, unless perfectly parallel. Once its gets to that side it binds up and starts grinding grain instead of crushing it. Meanwhile whole kernels get vibrated to the edges and fall through uncrushed.


It did work, but it drew blood and was inconsistant. I remember it working better for the test I did 11 years ago, so I'll assume my actions (or lack thereof) killed it. Once I get the MM I'm going to break this down and see if it's repairable, then just keep it for a backup.