On Tue, 18 Aug 2015 14:28:33 +0100, soup wrote:

Looking for a penetrant to get some seized parts separated.

Does anyone have a favourite (Plusgas, WD40, WHY).

DEFINITELY not WD40. Plusgas is as good as any I've tried.

I would prefer aerosol but am not immune to being told it's much cheaper
and really no more difficult to use a liquid.

If you use it in bulk, it's cheaper to buy in bulk then fill a spray
bottle, but...