Hi from a non phone enthusiast

[andy1702]

I see. So that abrasion is good enough for a smooth finish?

Yes, that's right. The abrasive properties of T-Cut or Brasso are so fine you won't be able to see any kind of scratches in the surface. You need something more abrasive to take out deep scratcjhes or discolouration, so that's why you start by either sanding or using Acetone to take the top layer off.

[TelePlay]

Just one suggestion, if you are going to use the acetone procedure, keep the cloth moving or run the risk of having it stick to the plastic and in doing so, finding you have created marks on the plastic that are worse than before you started (speaking from experience).

I dilute the acetone with denature alcohol starting with 25% acetone and moving up to a percentage of acetone that I feel is working well for the plastic being restored. I end up with 100% acetone at times but I prefer starting with a lower percentage in that I don't want to melt too much plastic too quickly. Testing on the inside is also a good way to determine the best concentration of acetone.

The alcohol mixture works nice in that the acetone will evaporate first leaving a wet alcohol surface which prevents the cloth from sticking to the plastic. The combination of chemicals and their strength is large so you can determine for yourself what best works for you.

When sanding out deep scratches, I now use a chemical mixture on the plastic before moving up to the next smaller grit size. I find the solvents knock the edges off of the prior grit sanding marks speeding up the next level of grit. Cuts the amount of time when sanding by a good 80%.

There is a lot of stuff on the forum by other members who have experimented successfully with "chemical sanding" or "solvent polishing." No specific board for those topic so you will have to use the search function.