Polishing Cut Perspex Rod

Fine wet-n-dry (going finer as you go, possibly used wet), held over a very flat surface and the rods held up as a bunch of 4 taped together if they are very close in length ... or individually if not and rubbed back and forth whilst rotating slowly till the finish is a good as can be, then finish with some T-Cut or similar on some cotton / denim, also held tight over flat surface.

Or if it doesn't matter if the end isn't perfectly flat and you don't mind a bit of scatter, use a polishing mop and wax on a Dremel, keeping the speed down.

If it were here I might first put them in the lathe and then put them on the linisher.

Cheers, T i m

Brian Reay was thinking very hard :

Flatten the ends first, with successively finer wet & dry, then polish up after the finest with a fine slightly abrasive polish such as toothpaste, Brasso, chrome polish, or similar.

Speed is definitely your enemy when polishing thermoplastics. I've been trying to polish a bit of "UV haze" out of some plastic headlights (carefully doing my practice on a bit of dummy plastic at the side, well out of the beam, just sitting in front of some decorative "chrome"). Even using a polishing mop in my cordless angle grinder at the minimum speed (which is pretty low), it's easy to melt the surface if you press a bit too hard.

If you have a spare to practice on, I'd sand the end best you can then wave it in a blowtorch flame.

I have done quite a bit of cleaning and polishing of 'plastics' (grp / Perspex / Plexiglas / polycarbonate) and in most cases I've resisted using any mechanical kit and done it by hand.

I think you can get much more feel and as you say, can make sure you don't melt anything as you go. ;-)

If something is scratched fairly badly all over you first have to make it look worse, with say some 1000 grade wet-and-dry (wet). You now have something free of scratches but opaque. Then you start with the finer grades till you get to the stuff that feels more like plain paper. ;-)

Once you are done there, T-Cut and finer cutting compounds to get it nice and transparent again. ;-)

The only real problem is any protective coatings there may have been.

I have done the above on several motorcycle windscreens, take the screen off and strip it back to the bare screen, support it suitably and off you go. ;-)

When done I's have to say that apart from any really deep gouges that you can really only just smooth out, it looks 100 times better and with some suitable polish, can generally stay that way for quite some time.

It's also quite satisfying, if a lot of elbow grease. ;-)

Cheers, T i m

Flame polishing might be the easiest solution if it doesn't have to be optically flat. Another easy option would be to wet the ends with clear epoxy and cast it against window glass with a mould release agent.

Polishing acrylic is possible but slow and tedious because it gets warm and softens when you work it. Expect to use much elbow grease and time.

Don't they also flame polish perspex but probably there is a skill level that is not learnt at the first attempt.

Much like the scary sharp technique for sharpening chisel blades where you end up with a mirror surface at the cutting edge.

Possibly look at some Youtube videos where they embed something in resin, turn it on a lathe and then polish it to a glass surface finish.

NT

No need for blowtorch. Standard polishing - finer up to 1200 grit wet-and dry, followed by T-cut or similar.

In the time taken to read this, you could have done an end

Yup. Well I couldn't. I don't have any perspex.

Used to be a product called Perspex polish in a tube tat looked like some substance in a kind of lint stuff. Brian

The Natural Philosopher pretended :

Brian has some!

Agreed. I can't see flame polishing working on perspex, the gap between "no effect" and blistering the surface is vanishingly small.

Access to a metallurgy lab would be good, they usually have a set of five different papers set up in a bench stand at about 10 degrees, with a water dribble across them, for hand polishing. They also use machine polishing, but remember that they mount metal specimens in thermosetting plastics, either epoxy or bakelite.

I was going to ask the same question,

I'm sure there's something you can wipe on....

Yet somehow it's done all the time and is quite easy. 'Flame polishing acrylic' is a good search term. Perspex is PMMA is acrylic.

Same as you'd do with wood or metal - get as smooth as possible using the same methods. Then Brasso to polish it.

I used one of the headlamp restoration kits to sort-out the hazed headlights on my old Saab 9-5. A slightly worrying process at the start but the end result was great and the lights continued to look good until I sold the car. I think my kit started at around 500 grit and went up to

it's industry standard practice.

you sure like hard life :)

NT