I am new here, just looking for some advice on heat treating.

[Blake.s]

So I am looking on some advice on heat treating.
So first I wanna ask should I get all my final sanding done on my knives first then heat treat? And after heat treat do final polish and sharpen?

Second is I have seen some stuff on heat treat and they said that before you oil quench that you get it to around what you think is the right temp and test to see if it is magnetic?'

Some of the metals I am using are railroad spikes, lawnmower blades, and some metal from school but I will have to get the metal details for that one.

I am very new to knife making, but I been building furniture and tons of other stuff through out my entire life. I was a welder, a CNC guy, a maintenance person and owned 2 companies before.

I have belt sanders but not the ones dedicated for knife making. But I was just gonna make one.
But I made a jig for files and thats working really well and I been learning alot with that.

So I just need some advice, prefer not to get flammed on my question and thats it thanks for anyone who responds.