Scaling (dirty) in cut keg

So I just got around to finally cutting another keg that i picked up like 4 years ago. All went fine, even drilled holes and added my weldless fittings. upon closer inspection the inside of the keg, like 2/3 the way up has a 5 inch band of rough scaling or caked on beer dirt. The color of it is light, so you can only really tell by touching it that it is there.

I hit it with a green scruby and lots of elbow grease which did nothing.... then since i already had the pressure washer out from earlier in the day, hit it with the 0 degree nozzle, which got it a little better but not all of it. This stuff is stubborn.

Any one have any suggestions for getting the scaling off?

Thanks......

Might try PBW or CLR? Don't know if either of those would work better than what you have already tried.

Good luck.

bar keepers friend might work...it might be beerstone if it is that tough and might require an acid wash.

Well, I left it soaking in water and joy dish soap (it is what i had handy) while I went to dinner (soaked for an hour and a half). I just went outside with my new found stainless steel scrubber and worked an 8 inch wide area.

I seem to have gotten it off with a lot of force. It took at good 5 minutes of hard scrubbing on that 8 inch area, but it seemed to work.

Now this has me wondering if the other keg i have that i plan on fermenting in has the same stuff in it? I cannot see inside of the keg to tell if it is there or not. I guess I will just do what others on here do, and put some pbw in it and put it on the burner and steam the crap out of it, then roll it around, dump it, and steam some more.

If there is beer stone in the keg i want to ferment in, will that impact my sanitary fermentation if i clean it as stated above?

thanks again.