This is the one thing that reliably changes what you get paid, and almost nobody does it.
Why mixed loads get priced low
If a bin has copper, brass, aluminium and steel all through it, nobody can weigh each metal separately without pulling the whole thing apart. So it gets weighed as one lot at a blended rate, and a blended rate always sits closer to the cheap end than the dear end.
You end up being paid steel money for copper. Separate it and the copper gets weighed as copper.
Telling them apart
- Copper. Reddish brown, goes green when it corrodes. Does not stick to a magnet.
- Brass. Yellow gold, heavier than it looks. Does not stick to a magnet. Most taps and valves.
- Aluminium. Light grey and very light for its size. Does not stick to a magnet.
- Steel. Sticks to a magnet. That is the whole test.
- Stainless. Shiny and heavy, usually does not stick or sticks only weakly.
A magnet off the fridge does ninety percent of the sorting. If it sticks, it is steel or iron and it goes in the cheap pile.
Worth doing
- Separating copper, brass and aluminium into their own piles or bins.
- Pulling brass fittings off copper pipe where they unscrew easily.
- Keeping bare copper away from insulated cable.
- Keeping radiators separate, and knowing whether yours are copper and brass or aluminium.
- Putting electric motors and compressors in their own pile instead of burying them in the steel.
Not worth doing
- Cleaning, degreasing or polishing anything. It does not move the grade.
- Stripping thin wire by hand. The maths rarely works.
- Cutting steel brackets off things with an angle grinder. Your time is worth more.
- Chasing the last few hundred grams out of a mixed bin.
If you are on a job site
The easiest version is not sorting at all, it is not mixing in the first place. Three buckets on site from day one and the load arrives sorted with nobody having done any extra work.
Sparkies and plumbers who do that end up well ahead over a year, and it costs nothing but deciding to do it.