As many may know I make a lot of special dividing plates, these are made from laser cut blanks usually out of a material called A36 which is a hot rolled steel plate that has a thick oxide layer on it.
There is an alternative material called HRPO which stands for Hot rolled picked oiled, basically A36 but cleaned up, costs more and not every company uses it of has it in the stock you want. They like A36 because the oxide layer stops reflection and also stops any dross sticking the the top surface.
Problem with A36 is the thick oxide coat destroys the tips on drills in a heartbeat, OK for the odd hole and if you heavily centre punch that also helps but many thousands of holes on a CNC is asking for a broken drill, especially in under 3mm sizes.
So what's special about HRPO ? Basically it's been through a commercial picking process, so if we can replicate this it helps with laser cut frames, angle iron and anything that needs to be finished, paint sticks the HRPO better than A36.
Picture of a plate straight from the laser cutters.

Also in the picture is a piece of bronze and a piece of copper to see how these perform. I'll say at this point the process didn't do much for them.
A tub was prepared out of an old plastic 5 gallon suds container by cutting the side out and a 'plate rack' cut on the laser to hold 20 plates which really only applies to me.

The solution used is Cementone Brick and Patio cleaner which is basically a weak hydrochloric acid. Don't buy any cleaner that says GREEN on it, that's just basically soapy water.
I mix this 1:1 with water and in my case it takes 10 litres of solution.
I put these in the tub last night at about 7:00pm and just been out 10:30 am following day and they are all clean and de-scaled, just need a rinse and a wipe with oil.


Even cleans the 'burnt' laser cut edge up.