I'm a recent convert to self drill screws, I'd self drill RSC magnets to insulated doors,

Have done that and they do hold well..

Thank you all for your positive and helpful replies. I was a little apprehensive about posting as a DIY'er but I've received a welcoming response.

I don't like asking too much from professionals as I should really be paying one of you to do the work and supporting your industry. My only reason for not doing so, is that I have a bit of a geeky interest in stuff like this and take pride in doing the work myself where possible. I've actually spent more money on my alarm than my 2x neighbors payed for theirs fuly fitted (just don't tell the wife).

When I next open the panel I'll take a few pics and let you all have a laugh at my attempt