Anyone have real-world luck with NSF H1 synthetics on spiral mixer gearcases running 75–85°C by hour three, versus the usual calcium sulfonate NLGI 2? I’m seeing soap separation on a 2019 Sancassiano after 6 months even with proper purge and lockout/tagout, and I’m trying to extend intervals without trading off safety or gearbox wear.
At ‘75–85°C by hour three’, purge, then H1 PAO VG 400–460 like Klüberfood NH1 94–402: https://www.klueber.com/us/en/products/klueberfood-nh1-94–402. Seal vents okay?
Did you completely strip the calcium sulfonate before converting? Mixed thickeners can oil-bleed or gel, so I’d food-safe flush and recharge with an H1 PAO using polyurea or aluminum complex at NLGI 1 to cut churning around 80°C; building on @baker_dario57’s base-oil note, here’s a handy chart: https://www.machinerylubrication.com/Read/1521/grease-compatibility-chart. It’s a bit like keeping frosting out of the ganache and it’s saved me six-month tear-downs.
I’d try softening the grade — food-safe NLGI 1 (even 0/00) with aluminum complex — and set the fill to roughly 30–40% of free volume to cut churning heat, like not overfilling a hot bowl of batter. @jsmithers300’s compatibility note is spot on, and a tiny desiccant breather on the vent stopped moisture-driven “soap separation” for us (example: https://www.descase.com/products/desiccant-breathers/). Will your seal stack tolerate a softer grade without weeping?
Try an H1 PFPE NLGI 1 on the 2019 Sancassiano; pricier but no ‘soap separation’ at 75–85°C.