Grinding keggle to remove rust?

So I got my 1/4 barrel sankey cut the other day by a welding shop. I got it home, cleaned it and noticed that the inside was covered in rust. I got on here, of course, and found out that I should clean it with CLR. I did this twice and I'm still looking at a good bit of rust. Some of the rust did come off, but it keeps showing up on the rough parts of the inside.

I'm wondering if there is a way that I can grind down the spots that have the rust on them down to the SS with some kind of grinding pad. Is there some kind of pad attachment that I can get for a grinder (or some other tool) that will do that? There's got to be a way!!!

Thanks for any info you can give.

I'm supposed to brew my first all-grain batch on Sunday so I'm getting desperate.

get a flap disc for your grinder and go at it. Just clean it real well after and consider re-passivating it afterwards. I didn't re-passivate and mine is fine though.

Elbow grease and sandpaper works wonders.

flap disk and grinder is a good call. Barkeepers Friend (BKF) will re-passivate the stainless, so you should make a good paste and put a coating on there and let is sit for a while.

You can get the flap disks at Home Depot or Lowes.
Get the 4 1/2" that go on a grinder.

drumming102 said:

get a flap disc for your grinder and go at it. Just clean it real well after and consider re-passivating it afterwards. I didn't re-passivate and mine is fine though.

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I've been trying to tell people this same thing, but some just don't want believe it.

passedpawn said:

flap disk and grinder is a good call. Barkeepers Friend (BKF) will re-passivate the stainless, so you should make a good paste and put a coating on there and let is sit for a while.

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On all of the SS or just the spots that I'm cleaning?

dmfa200 said:

You can get the flap disks at Home Depot or Lowes.
Get the 4 1/2" that go on a grinder.

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Is there a certain kind that I need? Like a certain grain or anything?

Only comes in 1 grit really. And no need to hit it all just smooth down the slag spots till they are even with everything and then just lightly hit the rust. It will come right off no problem.

If it were my kettle, I'd skip the flap disk (although I have one) and just paste the **** out of it with BKF). You're pickling metal.

I don't really know what I'm talking about. I hope someone with some knowledge steps up here. Monti?

uncleben113 said:

So I got my 1/4 barrel sankey cut the other day by a welding shop. I got it home, cleaned it and noticed that the inside was covered in rust.

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What your seeing is probably the slag and smoke from the cut of the plasma torch.
They should have filled the keg with water within a couple of inches from being full.
The water catches all the slag, and when emptied your keg should look as new as the day it was manufactured.
A welding shop would not have used a grinder,(unless their idiots) You can't cut stainless with Oxy-Acetylene, and every welding shop has a plasma torch, so that sounds like the most likely cause.

drumming102 said:

Only comes in 1 grit really.

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I noticed Home Depot has a 40, 60, and 80 grit for the flap discs. I'm going with the 80. That'll work right?

passedpawn said:

If it were my kettle, I'd skip the flap disk (although I have one) and just paste the **** out of it with BKF).

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I'm going to try this first

If 80's all you can get than yeah, but take it easy with the pressure.
A brand new 80 grit flap disk is a little on the aggressive side. They will loose their aggressiveness with use though.
Just hit it with light pressure.

passedpawn said:

If it were my kettle, I'd skip the flap disk (although I have one) and just paste the **** out of it with BKF).

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uncleben113 said:

I'm going to try this first

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If what you have is slag, and not rust BKF won't do jack.

dmfa200 said:

If what you have is slag, and not rust BKF won't do jack.

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I have both. Won't BFK take care of the rust that the slag is causing?

dmfa200 said:

If 80's all you can get than yeah, but take it easy with the pressure.
A brand new 80 grit flap disk is a little on the aggressive side. They will loose their aggressiveness with use though.
Just hit it with light pressure.

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Well what if I can get a 40 grit? I always thought that higher numbers meant less abrasion.

uncleben113 said:

I'm going to try this first

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uncleben113 said:

I have both. Won't BFK take care of the rust that the slag is causing?



Well what if I can get a 40 grit? I always thought that higher numbers meant less abrasion.

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BFK may remove any rust but definitely not slag. Slag is oxidized metal droplets that are created during the cutting process. They will fuse to the surface of the metal. Sometimes it can just be scraped off, sometimes it needs to be mechanically removed.

As for abrasives, the lower the number the larger the abrasive particles are.
Abrasives range from common grits as low as 36 grit(like tiny rocks glued to paper) to 4000 grit (which feels like paper)

ok so it just sounds like i need to grind it off. I'm pretty sure I can do that.

If you get a welder to cut the lid off of another keg have him fill it up almost all the way with water first so that any slag will hit the water cool down before touching and fusing to any metal.

ok thanks. and thanks everyone else for the info