Depending on who you are, even the smallest details on your final product could be the difference between something that looks MacGyver’d and a masterpiece. Polishing gives you a chance to take a rough edge and turn it into a smooth, styled finish. At Paragon, we have a handful of different styles we can add to an edge. Different finishes require different methods, ranging from liquid polishing products to fire.
Before proceeding, please take every possible precaution and safety measure when using any of the machinery, fire or chemicals mentioned below. Make sure an adult is present at all times. If you’re an adult, have another adult around. Also, you should be informed on the material you are working on. Most plastics should not be exposed to flames because of their chemical makeup. Fire can emit extremely harmful toxins and exposure could result in bodily harm. Read your material data sheets.
The saw cut finish requires no work beyond cutting your plastic pieces with a saw. It leaves a fairly-inconsistent pattern of grooves behind, which could be exactly what you’re looking for! In most cases, it’s not likely. But, if it’s up your alley, give it a clean shine with NOVUS #1.
A routered finish is similar to a saw cut finish, but the grooves can be more consistent as long as the fabricator cuts along the plastic at a constant rate. Slowing down or speeding up will shorten or stretch the pattern.
To get a bullnose finish, you’ll need a rounded router bit. There isn’t really much to it aside from keeping a steady pace around the plastic edge and letting the bit do the rest of the work for you. Rounded router bits come in various shapes. You can choose which best suits you, then trim the edges on each side to round the entire edge.
You can use a rounded router bit, like you would for a bullnose edge, but on a single side of the plastic to give you a radius edge. The image above shows a radius edge with a flame polished finish.
You can achieve a beveled edge by using a bevel router bit. Like the rounded router bit, cut the edge at an even rate to get a consistent-looking finish.
This is where it gets dangerous, or fun if you like dangerous things (another adult should be present at this point). After routing your plastic piece, giving the edge a clear and smooth finish can be obtained by taking a small torch to it. The pro’s use a hydrogen and oxygen mix to get the flame they need. If you don’t have access to that, a good alternative is getting your hands on a MAPP gas torch.
Before you ignite your torch you need to go through the following checklist:
- 1 – Is this acrylic?
- Yes – Great! Move on to #2!
- No – Stop what you’re doing. Depending on the plastic you’re working with it may easily bubble up and/or emit harmful toxins. You need to research your material and find out whether it is safe to expose to flames or not.
- 2 – Is this plastic film-masked or paper-masked?
- Film – Exposing film to a flame will cause it to melt to the plastic, making it more difficult to peel off after you’re done. Peel it back or completely off the acrylic to save your self some time. Also, I doubt it’s healthy to breathe in any of the fumes emitted from the melting film.
- Paper – Deburr any frayed paper-masking from the edge to prevent flare-ups when exposing the edge to a flame. Flareups can cause the acrylic to melt faster at the point that it occurs, which will be visible at the end. You can prop a steel object on top of the sheet to cover up the paper-masking so it doesn’t get burned.
- Removing the masking from the plastic is probably your best option. You can clean off fingerprints and dirt/dust with NOVUS #1 if needed.
- 3 – Am I fire-proof?
- Of course, you’re not. We haven’t reached that point in our genetic engineering department, so let’s stick to safety gloves and goggles for now.
- 4 – Do I have enough gas?
- Wouldn’t it be irritating to get to the last inch of your edge and run out of gas? Also, an unbalanced mix in gases can lead to undesireable results. Check your levels.
- 5 – Clear the area!
- It cannot be emphasized enough how important it is to keep all flamable materials, people and pets at a safe distance from your workspace. This is between you, the torch and your subject.
Once you’re through the checklist and know you’ve got acrylic on your hands, we can now light that torch! If this is truly your first time, don’t try to flame polish something that will be part of your final product. Practice on some test acrylic first so you get get a good rhythm. If you live or work near our warehouse, stop by and ask for some scrap pieces to test on. We often have plenty.
When flame-polishing, you need to be somewhat quick and totally consistent with your speed, moving the torch from side-to-side. However, you don’t want to be too quick, otherwise you won’t even see much of a change on your edge. Leaving the flame on one spot for too long,however, will cause it to melt too much, bubble up, burn or all of the above. Also, between “waves”, give the material a short moment to cool, then proceed.
That about covers it. Leave a comment with any questions or even suggestions on this topic and we’ll do our best to get back to you!