Rusty Grain mill

[Tbagger]

So my mill was sitting in storage for a couple years. Apparently it still had some grains between the rollers that got wet and corroded them. This is the best I could clean them up after going to town on them with acetone and a wire wheel. All the corrosion is gone but I can’t get rid of the discoloration. Moral of the story is, thoroughly clean your equipment before long term storage.

 

[Tbagger]

I couldn’t handle them looking like that. So decided to do a 10% sulfuric acid 90% water bath for 20 min and they came out looking like new.

 

[BeerChemistWhiskey]

I've had good luck removing rust from steel motorcycle parts with phosphoric acid.

5-10 minute soaks until the parts are shiny when rinsed with water may help clean those up a bit more and will help prevent any more corrosion in the future.

 

[Tbagger]

That’s what I was looking for but only had sulfuric and chromic acids on hand at the shop.

 

[augiedoggy]

coke cola should have worked too right?

 

[Tbagger]

coke cola should have worked too right?

That’s a little bit too caustic. I went with the more mild option of sulfuric acid. Lol

 

[cubalz]

Looks good but I am betting that it will now be more susceptible to future corrosion as the protective layer on the rollers is gone but as long as you keep an eye on it you should be ok. Nicely done!

 

[Tbagger]

Looks good but I am betting that it will now be more susceptible to future corrosion as the protective layer on the rollers is gone but as long as you keep an eye on it you should be ok. Nicely done!

yeah, if I can help it I wont be putting my brewery back in storage ever again. It's going to get a lot of love to make up for the last few years.

 

[IslandLizard]

Beautiful!

Phosphoric acid is recommended (The Navy uses it) over Sulphuric, which is way more corrosive to steel.

I would run some rice or old malt through there before milling for brewing.
Keep that mill clean and in a dry area. Those Crankandsteins are really good mills!

 

[augiedoggy]

Looks good but I am betting that it will now be more susceptible to future corrosion as the protective layer on the rollers is gone but as long as you keep an eye on it you should be ok. Nicely done!

nothing a little bar keepers friend wont help with or some olic? acid to passivate? (im sure I mispelled the acid type)

 

[Tbagger]

Beautiful!

Phosphoric acid is recommended (The Navy uses it) over Sulphuric, which is way more corrosive to steel.

I would run some rice or old malt through there before milling for brewing.
Keep that mill clean and in a dry area. Those Crankandsteins are really good mills!

I looked all over the shop for phosphoric but couldn’t find any so settled for sulfuric. After that I scrubbed them in running water for a long time but still plan on running some sacrificial grains before the next brew day.

 

[IslandLizard]

nothing a little bar keepers friend wont help with or some olic? acid to passivate? (im sure I mispelled the acid type)

You mean Oxalic Acid. I don't know if that's useful on non-stainless steel.

 

[Tbagger]

nothing a little bar keepers friend wont help with or some olic? acid to passivate? (im sure I mispelled the acid type)

If you mean oxalic acid, I’m not sure if it would help. I’ve never heard anything about it passivating sulfuric soaked steel. Might be worth looking into. I use it to bleach wood after I fractal burn it.

 

[augiedoggy]

I did, and yeah im not sure either but I believe there is a type of acid out there thats supposed to disolve the rust as well as treat the surface of the steel to help prevent it from returning.. I used it on my truck body years ago. it wasnt navel jelly which also works to clean up the steel.

 

[Tbagger]

I did, and yeah im not sure either but I believe there is a type of acid out there thats supposed to disolve the rust as well as treat the surface of the steel to help prevent it from returning.. I used it on my truck body years ago. it wasnt navel jelly which also works to clean up the steel.

I know phosphoric acid cleans and inhibits further corrosion but I didn’t have any.

 

[ancientmariner52]

I know phosphoric acid cleans and inhibits further corrosion but I didn’t have any.

Old sailor here. When we wanted to clean the bare steel decks in the machine shop, we'd beg a bag of unsweetened fruit drink mix (bug juice) from the galley. Mix it up in a gallon of water and it stripped rust like nobody's business. I think the active ingredient was phosphoric acid. The red 'flavor' left a faint color behind, the green and orange didn't. Only G_d knows what flavors they were supposed to be.

 

[MaxStout]

Phosphoric acid is so connected to the Navy, that there's a brand of rust remover called Naval Jelly. It's been around for ages, and you can get it at the hardware store. Brush it on, let it sit a while, rinse off.