We have a large parts washer taking space in our garage, ever since we closed The Workshop (see sig.) It's free-standing, about 38" wide and the same high (with the lid down) and 20" front-back. The fluid (e.g. paraffin or engine cleaner) is pumped through a directable nozzle and/or brush, drains back into a tank underneath, where the solids are trapped before the fluid re-circulates. There's also a light so you can see what you're doing. Note that this is pre-elf-n-safety, the only concession being a soldered link on the lid bracket, so when the fire gets hot enough to melt the solder, the lid slams shut! That said, it also comes with a 5lb CO2 fire extinguisher of similar vintage. This is all free to the first ukrmer[1] who replies "Me please", is able to arrange collection from south-east Essex, and can therefore save me the hassle of dealing with eBay muppets. The legs are removable and it lifts off the tank, so it should all fit in the boot of a family car, though it's not pretty other than pretty filthy. [1] with large parts to wash.
