How to install cabinet locks: the lock almost never fails, the tape and the alignment do

First, confirm the lock type can work on your doors

An install cannot rescue a lock that was never going to fit. Four checks, in two minutes, before anything comes out of the packet.

Door thickness, for magnetic locks. The key has to release a latch through the door. Skyla states up to two inches of door when the magnetic path is clear; Dreambaby publishes no figure at all. Hold the key on the outside and the latch on the inside and try it before you commit.

Metal in the door. Glass doors with metal frames, steel cabinets, and some composite doors with a metal core all block or distort the magnetic field. If the key works everywhere except one door, that door has metal in it and needs a different lock.

Surface for adhesive. Adhesive needs a smooth, sealed, non-textured face. Raw particleboard edges, unfinished interiors, waxed timber and textured laminate all fail - which is why several sets include screws for particle board and say so on the box.

Hardware, for handle locks. A U-shaped slide lock needs two knobs or pulls no more than 8.5 inches apart. Single doors, drawers and handle-less cabinets need an internal or external latch instead; which lock suits which door is set out on cabinet locks for knobs, handles and no hardware.

The surface prep that decides everything

Isopropyl alcohol, a lint-free cloth, and let it dry. That is the whole technique, and it is the step people skip because the inside of a cabinet looks clean.

It is not. Kitchen cabinet interiors carry a film of cooking aerosol, and every multi-surface spray and furniture polish leaves behind silicone or wax designed to make surfaces repel water - which also makes them repel adhesive. Alcohol strips that film; soapy water redistributes it.

Temperature matters too. Most pressure-sensitive adhesives want somewhere above about 60 degrees Fahrenheit to flow into the surface. In a cold kitchen in winter, warm the door and the lock with a hairdryer on low first, and the bond you get will be noticeably better.

Alignment: use the template

A magnetic lock has two halves: the latch on the door and the striker or catch on the frame. If they are a few millimeters out, the latch drags on the striker as the door closes, the door stops sitting flush, and within a fortnight somebody has disengaged the lock because the cupboard "sticks". That is the real failure mode of this product, and it is an alignment problem rather than a product problem.

The fix is in the box on better sets: a paper template or a plastic positioning cradle that holds the two halves in the correct relationship while you mark or press them. Dreambaby ships a template, Skyla ships a cradle, and both are worth more than they look. Where there is no template, fit the latch first, close the door, mark through, and fit the striker with the door shut so the geometry is set by the closed position rather than by your eye.

Cure time, and why week three is when locks fail

Adhesive bonds develop over time: initial tack in seconds, most of the strength in a few hours, full strength in 24 to 72 hours depending on the tape. A lock that is pressed on and then yanked by a toddler the same evening has been peeled before it ever bonded, and it will hold for a while on the remaining contact area before letting go - which is why so many of these fail two or three weeks after a weekend of babyproofing.

Press firmly for a full thirty seconds per lock. Then leave the cupboard alone overnight. If you are doing a whole kitchen, that means fitting everything on a Saturday and testing on Sunday, not testing as you go.

What to buy for each door type

Now that the install is clear, the choice is between an internal magnetic lock, an external adhesive latch and a no-install handle lock - and which one you want depends on your doors rather than on which is best in the abstract.

When to use the screws instead

If the set includes screws, there are three places to use them without hesitation: drawer fronts, which take a straight pull with no hinge to absorb it; the cupboard holding cleaning chemicals, where the consequence of a failure is a poisoning rather than a mess; and any door made of particle board, because the makers themselves say the tape is not enough there.

Pre-drill a pilot hole so the panel does not split, hold the screw against the edge of the door first to check it is shorter than the door is thick, and drive it by hand on the last turn. Two small screws on the inside face of a cabinet door are invisible when the door is shut and fill in thirty seconds when the childproofing years are over. If you rent and screws are not an option at all, the adhesive-only route is on how to babyproof cabinets without drilling, and the ranked locks are on best cabinet locks for babyproofing.