Habitation door

You may well recall my previous post “habitation door security“. I have now received the Milenco security door lock which I want to fit to our two berth Nuevo EK bought new in December 2010.

This door lock can be fitted portrait or landscape and can be locked both inside and out.

Have any members got advice on:

Drilling into the exterior wall and the type of drill bit to be used.

How to prevent the drill bit slipping on the exterior surface.

I have read that adding sealant into the holes created is a good idea-why?

Once the lock has been fitted what sealant if any should I apply in addition to the gasket provided - to prevent any water ingress?

I look forward to receiving your observations. Many thanks in advance

Just to let you know that I fitted to the habitation door of our Nuevo - the Milenco Security Door Lock yesterday despite there being no instructions in the box!!! No advice was given as to the bit sizes to be used etc. Thank goodness I was able to view three videos on youtube plus an article which I had filed which appeared in the July 2019 edition of MMM.
There is enough stress in life......why can't firms like Milenco just offer some help to the poor customer?????????????