Drilling Perspex. Any Tips

D

Daydreamer

Well-Known Member
Joined
20 Aug 2009
Messages
268
Visit site
Its a long piece of Perspex for a boat window and it needs about 40 holes in it. Cutting and shaping it seems easier than I remember from occasional small projects in the past but I was quite alarmed by some practice attempts at drilling it, which I don't remember being a problem.
The Perspex climbs up the drill or blows out the bottom of the hole being drilled. All very worrying on fifty quid's worth of Perspex.

All advice gratefully received.
 
Best done with a purpose made drill bit. Faster helix and more acute point angle than for metal. You could buy, or try grinding a normal drill to around 60 or 70 deg. as a makeshift.
Also sounds like your clamping, if any, could be improved
 
Daydreamer said:
Its a long piece of Perspex for a boat window and it needs about 40 holes in it. Cutting and shaping it seems easier than I remember from occasional small projects in the past but I was quite alarmed by some practice attempts at drilling it, which I don't remember being a problem.
The Perspex climbs up the drill or blows out the bottom of the hole being drilled. All very worrying on fifty quid's worth of Perspex.

All advice gratefully received.
Click to expand...

Try a new drill bit ,dont try to force drill not to fast try water as a lube its as simple as that ,you could even try a hand drill rather than electric
 
I've always put masking tape on first, mark the centre of the hole on that, then go very gently with a new drill bit. All on top of a plank of wood & kneeling on top...
 
I use a brad point, also known as spur, drill when cutting Perspex. It is a woodworkers drill for dowels. Always drill from both sides of the material to avoid the hole being damaged as the drill bursts through. You don't need to clamp the Perspex to aluminium but have something underneath, keep the speed down 250-300 rpm to avoid burning.
 
Last edited:
Clamp the workpiece to a solid wooden backing piece to reduce break-out. Slow and sharp with light pressure. Let the drill cut; don't force it.

It's worth getting someone to show you the proper way of sharpening a drill by hand: it's difficult to describe or show in photos/video but relatively easy when you know how.
 
Last edited:
I put two layers of tape over the area of the holes then measured where the holes needed to be and marked the tape, that stops the drill bit sliding. As said don't push hard and go slowly otherwise it will melt the perspex.
 
If you can grind a drill properly then increase the angle from the 120 to about 160-170 degrs, this is not easy. I have had much success using a stepped drill, but whatever method you use clamp a scrap piece of Perspex below the hole, then the sacrificial piece will crack not the top piece. The best solution is to find someone with a cnc laser cutter.
 
Perspex is a trade name for acrylic sheet. There are many other trade names for acrylic sheet. I found that 8mm clear (colourless) acrylic sheet is relatively easy to find, tinted 8mm sheet is rather more difficult to source. But google '8mm tinted acrylic sheet' and a few suppliers come up.
 
Persex/acrylic gets very brittle with age. It will split even new - if sawed or drilled to roughly.

Polycarbonate is altogether tougher - as used for prtective screens etc. It also very easy to work - drills and cuts easily. For that reason I used polycarbonate when I re-glazed mine. The acrylic I took out was so brittle it would shatter with a light hammer tap ! ( it was 30 years old though )

Polycarbonate does not have such a hard surface - so marks more easily.

Its not much dearer than acrylic - but more difficult to source tinted, brown blue etc.
Security glass for windows is plycarbonate - Lexan I think ?

Geoff
 
You must log in or register to reply here.

Share this page

Top