Silver_WRX02

I need some suggestions on lapping a TRUE. I heard that the bottom is Nickel Plate. Is it easy to remove? Is 220 grit a good start or 180? I have see people starts with 180. How long do I have to lap with 220 grit? (Until all the Nickel plate gone?)
Should I wet sand and use Hand Dishwashing Liquid all the way? I bought a lapping kit though internet, but it comes with small piece or sandpaper 5 inches by 3 inches. Will that be ok or I need to get larger size from Hardware store?

Thank you All.

Updates

Just lap my TRUE today. My lapping kits' sandpaper is too small and weak. I can't remove the Nickel plate. I can just remove the lay of paint, but some paint still on the it. I use 220 grit and lap it 3 hours, then I decide to make the nickel plate smooth. I gotta go get 180 grit then lap again when I have time. The temp has drop about 5-10c. It i can remove the nickel plate, the temp may get lower. Right now the room temp is 82F and Coretemps are 40c 39c 34c 33c.

sunburn39

Yes, the bottom is nickel plated and it takes forever to remove completely, from my experience anyway. You'll notice it coming off within the first few minutes, but to get it all off will take a while. I started with 180 grit and stuck with it until all the nickel was gone.

You're going to spend 80% of the time on the lowest grits getting the thing flat. The high grits are mainly for smoothing out the scratches left by the lower grits. It's the low grit that does all the work and flattens things out. I've read people starting at 400 grit, but I can't imagine how long it would have taken me if I started there. Those sizes should be fine. I used 8.5x11 sheets I think. You may want more sheets of the lower grit though. They wear out after a while.