Best way to polish drill holes in perspex/acrylic

BarryA · Post by **BarryA** » Wed Feb 27, 2008 9:43 pm

What is the best way to polish drill holes in perspex?

It might sound like a weird thing to worry about, but I'm mounting 5mm LED's into these holes and I'd like to polish them up a little to improve the optical clarity.

Does anyone have ideas of the best way to do this? I've considered buying a dremel and some polishing brush attachments, but I'm not certain which of the available ones (if any) would be appropriate to use with perspex.

Cheers,
Barry.

Teabag · Post by **Teabag** » Wed Feb 27, 2008 9:58 pm

hi barry,

at work they polish acrylic all the time using paint t cut type products for cars, I have posted the name in another post cant recall the name atm...

a dremil type drill would be fine, when I was a tool maker we used to cut a slot in the end of a bar to slide emery cloth in to polish a drilled/bored hole, you could do the same with cloth and T cut type product rotating in the dremil type drill, put in the hole to polish it. if you cant find a ready made polishing attachment to use.

Stoday · Post by **Stoday** » Wed Feb 27, 2008 11:42 pm

I've polished acrylic cuts with emery cloth too. Use cloth, not paper and keep it wet. Spit is best.

BarryA · Post by **BarryA** » Mon Mar 03, 2008 12:51 pm

Thanks for the suggestions.

I wasn't too worried about the sides of the drill holes, more so the end where the light would be shining through. The holes weren't drilled all the way through since a glass bowl containing water and decorative stones will be placed on top once the thing is finished.

I got the dremel along with some polishing attachments. I used the brass bristle one, followed by the nylon bristle one with some of the polishing compound. Its not come out perfect, but its a heck of a lot better before.

I'll experiment a little more and see if I can improve it.

Cheers,
Barry.

Wood Magnet · Post by **Wood Magnet** » Mon Mar 03, 2008 7:17 pm

Cannyfixit · Post by **Cannyfixit** » Mon Mar 03, 2008 11:23 pm

I have a perspex screen on my visor and had some very fine scratches on it I found Meguiars PlastX worked a treat,
http://www.theultimatefinish.co.uk/Stor ... ductId=320

BarryA · Post by **BarryA** » Tue Mar 04, 2008 10:12 am

I promise to put some pics up eventually.

At the moment its nothing more than a disc of perspex with some holes in it.

Post by **ultimatehandyman** » Tue Mar 04, 2008 5:30 pm

If you could heat the holes to the correct temperature it would give a polish effect.

It's very difficult to do without damaging the perspex though.

This is how the professionals do it-

<embed src="http://www.ultimatehandyman.org/flvplayer.swf" quality="high" width="450" height="367" name="VideoPlayer" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" flashvars="file=http://www.ultimatehandyman.org/uploads ... r=0xFFFFFF" wmode="transparent" border="0"></embed>

Cannyfixit · Post by **Cannyfixit** » Tue Mar 04, 2008 7:19 pm

That interesting might have a play when i get 5 minutes

Jaeger_S2k · Post by **Jaeger_S2k** » Tue Mar 04, 2008 7:56 pm

Cannyfixit wrote:I have a perspex screen on my visor and had some very fine scratches on it I found Meguiars PlastX worked a treat,
http://www.theultimatefinish.co.uk/Stor ... ductId=320

Brasso and the posh one Stoday uses does this well for visors mobile phone screens etc.

bredred · Post by **bredred** » Thu May 07, 2009 10:12 am

The best way by far is to flame polish it as UHM says........but it is actually much easier than you might think, particularly if you are using cheaper extruded acrylic - cast acrylics are not so easy.

I flame polish using a torch - basically a plumbers torch.

Practice first on an off-cut

Form the torch flame to a point - quite a hot flame, but not "roaring". Approach the acrylic with it and, keeping the flame moving. Its a bit like oxy-acetylene welding in so much as you apply the flame at one point, fan away from it so as to not overheat it and then you fan back towards that same area. It is a very simple process and just needs a bit of practice on off-cuts. You will very quickly get the hang of it and know the heat, distance from the acrylic, the speed of movement etc

The effect is to leave a "glass like" finish - it is ideal for edges, drill holes etc and can help with scratches.

As stated, this works brilliantly on extruded acrylic. For cast acrylic it can help but is not anywhere near as effective - perhaps mechanical polishing is better for that.

Link below is for torch i have from b&q

http://www.diy.com/diy/jsp/bq/nav.jsp?a ... earch=true