Fixing a numberplate

Unless the surface is dead level and cleaned of any polish then they do come off !!

if it is a perspex plate then it is usually possible to use a bog standard drill bit, but if you let the drill bit hack into the plate then they can shatter! I usually use a standard bit and a drill press, so I can control the speed the bit goes in, I am also usually fitting new plates which are less brittle. Proper perspex drill bits are a strange rounded shape at the end, so you could probably use a tile drill bit if you have one. oh and drill it from the back so you don't seperate the backing from the perspex.

Any metal or probably wood drill bit will be fine. Use a low ish speed. Don't lean too hard or you'll crack it. Clamp the plate to a bit of wood.

An ordinary twist drill. Use a slow speed to prevent melting the plastic. Start with a 3mm (approx) drill and then enlarge.

My local Police (Sussex) are giving away special screws which make it harder for someone to remove the plates - there has been a spate of thefts in the area, apparently. It may be something to consider ...

D A Stocks

Use RTV instant gasket instead. . I had the same result with some number plate pads from Halfords. I was fitting some new plastic plates, and didn't want to use screws as apart from looking untidy, over time, water tends to enter the screwholes, and discolour the area around them.

The pads were obviously not going to work. especially on the front plate which was attached to a curved front bumper. I got around the problem by using RTV silicone instant gasket instead. Two generous beads along the length of the plate, with some tape each end to hold the plate in contact with the curved bumper overnight whilst the silicone was setting.. After removing the tape the next day I tried pulling the plate it off. It was so firmly stuck that I'm sure it would have broken, rather than come off in one piece. The rear plate was on a flat surface, but still needed to be held in position until the silicone set. That was done about two years ago, and the plates are still solidly fixed. Mike.. .

As I mentioned in my earlier post, mine are stuck so firmly with silicone sealant, that I doubt they could be removed without breaking them. I doubt a thief would be interested in using a broken plate. Would still be an expense to me though. Mike.

I used some contact adhesive a few years ago on an old corsa s*it box, that did the bizzo too.