Always hunting monos. Though if you have access to gear pumps I guess they are equally self priming so could also pump feedstock out of drums.
But not lumps ... they don't like it up'em.
Gear pumps aren't for horribly dirty oil. You've probably seen the other thread on pre-filtering feedstock. I think the key is to heat, suck with some sort of pump using a foot valve and strainer, then pump the heated discharge from the pump to another tank via a 200 micron strainer.
Those mono's sound expensive, but if you see one going at sensible money, I'd love one :-)
