Fikret

One thing worth doing whichever material you use: test the pair before you trust it.

Hang the cleat, hook the mating piece on, and load it with considerably more than the intended weight — sit on it, or hang a few bags of something heavy. Better to find the fixing that missed the stud on the floor than with a cabinet full of glassware attached.

Takes two minutes and I have found a bad fixing this way more than once.

One case where the principle genuinely bites: never rely on a screw into the end grain of a shelf to hold anything.

That is the classic failure in cheap furniture — a screw driven into the end of a board, holding a load, working loose. If a design puts you there, the fix is a dowel or a cross-grain insert placed so the screw bites across fibres instead of between them.

Once you know the rule, you start noticing it in every piece of furniture that has failed.

There are reasons to avoid it that go beyond performance, and the first one is likely to settle it.

It may well be illegal where you are. Used engine oil is classified as hazardous waste in many jurisdictions. It must be collected and taken to a proper disposal point, and applying it to timber that will sit outdoors in the weather is disposal by another name. Rules vary and it is worth ten minutes checking yours, because "the builder suggested it" is not a defence.

It is a genuine contaminant. Used oil is not fresh oil. It contains combustion products, metals worn from the engine, and additives that have degraded. Applied to timber outdoors it will leach into the ground with every rainfall, and it will do so for years.

For a bin enclosure at a beach house — near sand, near drainage, near water — that is the part I would weigh most heavily.

Whichever route you take, mind the outer veneer. Birch plywood has a thin face ply and any trimming operation that lifts or chips it leaves a mark that shows through finish.

Scoring the cut line first, cutting with the good face oriented so the tool exits into the waste, and using a sharp bit or blade all help. On a door, the edges are exactly where people look.

One thing about the tops themselves, since you are gluing boards up: pay attention to how you arrange them before glue-up.

Alternating the growth ring direction between adjacent boards is commonly recommended to limit overall cupping across a wide panel. Matching colour and grain across the joints matters for appearance, and on a desk you look at it for hours.

And finish both faces equally, including the underside. A panel sealed on one side only takes on moisture unevenly and will cup — which on a desk that moves between houses and climates is a real risk rather than a theoretical one.