It is highly recommended that respiratory protection be used during the sanding and polishing procedure. If nothing else, use a T-shirt that is tied so that it covers the nose and mouth.
Polishing is comparable to lapping in one regard. The smaller the clefts, the more reflective the surface becomes.
That being the situation, then the quality of the final outcome depends heavily on the first step; the initial cut.
These are the tools that I use to polish acrylic. For the most part I use the hand-held drill (not shown above, but later on in this post) as I seem to get the best results with it
Here is a freshly-ripped 12”x 9/16” piece of acrylic that was cut from a ½” thick sheet of acrylic.
The image below depicts two stages of preparation in polishing. The bottom piece still has some saw marks that are deeper than what I would consider acceptable. This was caused by a slight rocking motion as the saw blade passed through the piece. The ambient lighting has amplified the flaw, which barely registers as I run my finger across the piece. Never the less it must be sanded down as that flaw will show clearly when the piece is polished.
The top image is a piece that is ready for the final sanding. I used an orbital sander and a 120-grit disk to smooth the surface out. It does a nice job, but in the end the sanding marks are small curly-cues and they need to be lines that are parallel to the long axis of the piece
The orbital sander in the image below is the unit that I use to shave down the worst of my mistakes.
This image shows the slight ribbing that the travel of the router bit left behind. This is the point that I would consider the last lap of fabricating a piece.
The finishing stage includes 320, 400, and 800 grit sandpaper and a block of red rouge. I use the red rouge as it facilitates less sanding and can polish more half-assed sanding jobs in a pinch.
320 ~ used to smooth the ribbing and the corners of the piece
400 ~ smoother
800 ~ and again, smoother
When polishing large panels, I clamp the work and manipulate the drill. But, that is not always the easiest technique when it comes to smaller pieces. When this is the case, I use a standard drill with a muslin wheel attachment that is gripped in a vice, and I use a Velcro strap to keep the switch depressed
The image below shows a piece that is fairly clean, but all the visible flaws need to be removed:
Once the piece is sanded to a uniform satin-sheen, then it is ready to be polished with the rouge. At this stage there may still be tiny (barely visible to a 20/20 sight) scratches and marks in the surface, this is fine as the polishing compound will remove them
Here is a piece that is ready for the polisher.
And complete. I tried to get closer (with and with out the Marcro function) but the camera could not decide what was the focus and every shot came out very blurry.
