Ok, i found a few posts touching base on polishing edges, but im hoping tinkerman can shed some wisdom on this. I thought of picking up a dremel with some polishing wheels, has anyone tried this? or is sandpaper and metal polish sufficient?
The Dremel is a wonderful tool, but that polishing wheel is all too easy to friction burn the acrylic.
If your doin it yourself, stick with wet-o-dry sandpaper and work your way throug the grit #s all the way to 1000 if you can get it. Then, you can polish from there with some automotive swirl remover (try 3M Mirror Finish Hand glaze or MaGuires swirl remover) and a buffing cloth. Laborious, but it will get the job done.
These are really amazing pads! I took a 1000 grit pad to an edge that was done with conventional sandpaper and polishing compound and it brought it to a crystal clear finish with just a trace of scratches left. These things go all the way up to 2000 grit. Worth looking for as an alternative to sandpaper. They can be easily cleaned and last a long time. I first used them to polish a stainless steel food service table I built for the restaurant I work for. Great product!
I’m an Industrial woodworker with loads of experience in plexi-glass fabrication. When I need to polish an edge , I simply flame polish. It’s done with a torch ( usually a propane torch with a pencil flame tip ) . I will pass over the edge 3 or more times lightly so that it dose’nt deform the edge or sheet ,or begin to burn or bubble.
The edge should be a little prepared first for the best finish. Ideally run the edges over a jointer first, thats usually enough. But if you want to make it even easier also take a scraper back and forth on the edge to eliminate any jointer ripples. This will make the flame polishing quicker with less chance of a burn.
Obviously not everyone has access to a jointer, alternatively , a good scraper will do the job ( or an electric hand planer) , just take more time.
The end result is a crystal clear edge like water.
Another good way is to friction buff the edge, a bit messy and you do need a special wheel and compound. This method will also leave a crisp corner on the edge top and bottom, unlike flame polishing that will soften the edge corners as it melts.
Although sanding in stages will work quite well, its a lot of work to achieve a clear edge at best with micro scratches ( that probably does’nt matter any how ).
For most, without the right machinery sanding is the safest and most practical.
However if you want to attempt this method, practice with scrap and don’t burn your fingers, it does get hot. Also polish with the piece up and down ( vertical ) . Not laying flat. This will not achieve an even melt.
I actually used both sand paper and a blowtorch to flame polish. When I did my first practice run with flame polishing, I noticed that you still keep some diagonal lines where the saw has cut the acrylic. So I first sanded the sides down to get an even surface, and then did a couple of passes with the flame to get it transparent.
That would be the purpose of using a scraper in my description. Its much quicker than sandpaper and won’t leave scratches from the sandpaper, even if you can’t see them.
Did you try and compare both methods? ( sanding and flame polishing )
I’m curious to know if theres even a slight difference.
( the scraper is simply a piece of old handsaw blade cut into pieces about 1 1/2” x 3” or so with the edges filed flat leaving an edge that will grab when its dragged across a surface or edge. ) you can also buy them if ness.
That would be the purpose of using a scraper in my description. Its much quicker than sandpaper and won’t leave scratches from the sandpaper, even if you can’t see them.
Did you try and compare both methods? ( sanding and flame polishing )
I’m curious to know if theres even a slight difference.
( the scraper is simply a piece of old handsaw blade cut into pieces about 1 1/2” x 3” or so with the edges filed flat leaving an edge that will grab when its dragged across a surface or edge. ) you can also buy them if ness.
I haven’t compared the two as I wasn’t familiar with the scraper unfortunately; it does sound pretty handy. Even so, working my way up from rough to fine sanding paper and then flame polishing the whole thing, it took me two hours tops to do all 4 sides on my acrylic. It’s very transparent, and I’m getting great blobs.
My solution, which was very easy and crystal clear, was to drill holes into the acrylic, and fill the holes with optical gel (same refractive index as glass) and then push the leds into the gel, filling all the roughness which so marred the amount of light getting through by scattering it. I had access to this stuff through my dad’s work, but if you could find any two part curing acrylic/epoxy, or something similar, I think it is much superior to the alternatives.
My solution, which was very easy and crystal clear, was to drill holes into the acrylic, and fill the holes with optical gel (same refractive index as glass) and then push the leds into the gel, filling all the roughness which so marred the amount of light getting through by scattering it. I had access to this stuff through my dad’s work, but if you could find any two part curing acrylic/epoxy, or something similar, I think it is much superior to the alternatives.
Except for when you blow out one of your LED’s and you need to replace it, I guess..
My solution, which was very easy and crystal clear, was to drill holes into the acrylic, and fill the holes with optical gel (same refractive index as glass) and then push the leds into the gel, filling all the roughness which so marred the amount of light getting through by scattering it. I had access to this stuff through my dad’s work, but if you could find any two part curing acrylic/epoxy, or something similar, I think it is much superior to the alternatives.
When I need to fuse ( weld ) acrylic together I use Methylene Chloride. It creates a crystal clear bond, almost instantly. Working time is measured in seconds. The strength is as if it was always 1 pc. of plastic.
In your application I would insert the LED’s then with a syringe drip in enought Meth to fill and cap the back of the LED. The tighter the fit with the LED’s the better for clearity and no air bubbles. End result would appear that the LED’s were cast with the acrylic.
PROBLEM: Methylene Chloride will “ melt “ to fuse acrylic. It does not do this to all plastic types. I would think that if it melts through the LED casing layer the LED would’nt be any good afterwards? However, if it only deforms the casing a bit while its in the hole and fuses complely then a change in its shape really should’nt matter consideriing its already “ in “ the acrylic. Hmmm?
CAUTION!! Methylene Chloride is not a chemical to mess with carelessly. hand/eye protection should always be used, no open flames or near heat sources...and don’t drink it ... it’s not moonshine. lol
My solution, which was very easy and crystal clear, was to drill holes into the acrylic, and fill the holes with optical gel (same refractive index as glass) and then push the leds into the gel, filling all the roughness which so marred the amount of light getting through by scattering it. I had access to this stuff through my dad’s work, but if you could find any two part curing acrylic/epoxy, or something similar, I think it is much superior to the alternatives.
Except for when you blow out one of your LED’s and you need to replace it, I guess..
That is a very valid point. Actually, the stuff I’m using doesn’t cure, so LEDs are easily replaced.
