What works for me: Buffing and polishing acrylic

KikBox

On my last project I discovered a pretty efficient method for polishing acrylic and I thought I would share it. Everyone has their own ideas about how things like this should be done and many times it's a function of what supplies you keep on hand. Before starting this mod I consulted others to find out what there experiences were and then developed my own technique.

I am fitting the bottom of the case with a 1/4" thick sheet of acrylic. I am using cast acrylic for its clarity. This feature has 2 functions, I plan on using it for a lighting experiment to edge light the bottom of the case and also as a window feature on the bottom of the case. Anyone who has ever followed any of my work logs knows, I like floor boards on the inside of my cases. I just think they look sharp. However, for this case I decided to do something a bit different, I am cutting out the bottom of the case and creating a large window that will allow light from the fans to spill out the bottom of the case.

Polishing plastic takes some time but if you have the patients there is a big payoff. I like to shape things by hand whenever possible and on this case I wanted the acrylic plate to have nice beveled edges. I clamped my belt sander in my bench vice and began to work the plastic one edge at a time. Using 120 grit sandpaper, I was able to quickly get the shape I wanted. With practice, you will be able to get nice even beveled edges on all sides.

Once the bevels were created I moved on to wet sanding. Using 400 grit sand paper and water I sanded all the rough spots out of each of the edges. It took about 40 minutes of alternately sanding and dipping in water to get the nice smooth edges I was looking for.



After wet sanding I moved on to polishing compound. Many people like to sand with finer and finer grits but I have found that my Casewell polishing kit allows me to skip these steps. Using a medium grade compound and wheel I am able to achieve a glassy finish. I followed that with a polishing rouge that's the consistency of lotion. Following this final step the acrylic is smooth and clear as glass. Polishing in this way is a messy business but you will get a super high shine.











The edges turned out better than I expected. They were very glossy and smooth to the touch.





I have 3 120mm LED fans inside the case that put out a ton of light. This window features produces a nice green wash of light below the case without having to install any extra lights below the case.

OctaneMotorsports

Awesome! Thanks a lot man...

Grez

Great guide, and to the point. Nice, Stu!

R.Carter

Speaking of polishing acrylic, anyone now how to fire polish it? I have heard about it, and seen the results of it, but am very unsure about the process.

KikBox

Flame polishing is a fast way to get a nice finish if you have the equipment. I have a simple propane torch that I have used in the past but I was not willing to experiment with this project since I only had one piece of acrylic.

You need to find a torch that allows you to control the flame. You want a small, hot, clean flame. You also want a flame with a pointed shape so that you can control where the heat goes. A welding or propane torch could do the trick. They also make torches just for flame polishing but I am guessing they are not cheap. There should be no smoke and the flame should be almost invisible. Sand down the edges of the project with fine sand paper and then clean them off really well so there is no dust or plastic particles on them.

Run the flame back and forth along the edge of the plastic rapidly making sure not to settle in one area for too long. Obviously, you don't want to burn the plastic. The object is to quickly heat the edge of the plastic. When you melt the surface of the material, surface tension smooths it out.

I put my piece on a spinning platform and use a propane torch and it was fast an easy.

R.Carter

So attaching it somehow to a Lazy Susan would do the trick?

Thanks!

KikBox

Yeah, the lazy susan just makes it easy to spin around while you are flame polishing the edges.

Sanat

I want to join acrylic sheets face to face. I have used WELD-ON solvent cements, but they give me bubbles. Any suggestions?

Temp.Asdf.Asdf

TAP plastics has some good information on this ... I followed there steps and got some great bubble free joins ... ( once I was able to cut straight clean lines, )

Here's a youtube link to TAP plastics, look them up they have other guides
TAP Plastic How to glue Acrylic youtube video

Cutting the acrylic to get smooth flat lines is the trick.
I'm using a jig saw with a plastic cutting blade (home depot), a acrylic specific blade will work better. The grooves are upside down from regular wood blades. Mark off the line to be cut. clamp boards on both sides of the acrylic, leaving a gap between the boards where I will be cutting. I did this to keep the piece hanging off from bending and snaping off from the main sheet (wasted a bit of acrylic not using the support boards)
To keep the jig saw straight while cutting I'm clamping a thick yard stick to the top of the sheet (like a table saw fence rail.)

If you have a table saw they have acrylic specific blades that make crystal clear cuts but they are pricey, a local shop had one but it was 80 Bucks!
I bought the acrylic cement for 6 bucks and 4 bucks for the application bottle

I've starting cutting some 5"x5" squares to play with
after about 10 cuts I was able to make clean lines.

I found the joining liquid in the video local for 6 bucks at a plastic shop

Sir_Loin

I know I' late to the party on this one, but here's the scoop.

The best setup to flame polish is a hydrogen/oxygen rig. You can use others, but they don't work as fast. Correct, the flame should be "invisible", and you can polish the edge with a single pass (the torch is key too). As you go along, you'll see the flame flare up at the edge of the plex...that's when you know you've done it right.

You can use a compound and wheel as has been shown, which is probably the most cost effective for most.

Zenshi

Hydrogen/Oxygen torches are pretty cool (or should I say really hot). Invisible flame, really high temp, clean burn and a flame that actually drips water.

Kikbox
Not only is this a great guide but that case you show is d*mn sexy. +1rep from me.

photonlust

Is there anything wrong with trying CD scratch remover (not cleaner)?

norriej

Hello, this is Joseph Norrie, President CEO, Norrie Industries Inc. I would just like to share with You a better Acrylic Flame Polishing
kit than what it is commonly in use. The primary advantage of our product is that there are many different tips to choose from, making the
torch much more versatile. Our products are made entirely in the United States and are of superior quality.

If you're not already familiar with the process of Acrylic Flame Polishing, our method uses a Hydrogen Oxygen Flame to produce up to
an optical finish with little effort. Much faster than buffing or other polishing methods. We offer kits in addition to Flame Polishing services
for those who wish to do it on their own.

Please Visit Our Website: www.acrylicflamepolishing.com for more information. Or feel free just to Call.


Thanks,

Joseph Norrie, CEO
Norrie Industries Inc.
1320 Luke St.
Fort Collins, CO 80524

970-412-9567

acrylic@acrylicflamepolishing.com