My method is to let the pans cool upon shut down. A couple of hours later I could drain the pan and add vinegar, but since I'm long gone by then, I drain and add white vinegar in the morning. My syrup pan is 3x3 and I only use 1 gal vinegar. I then use a weed burner torch to warm it from under the pan, heating it until a steam like vapor starts to come off it (the temp is likely just above luke warm). I then let it set for an hour or so. Then I use a gentle brush to check if all sugarsand has loosened. If yes, I drain, then I flush the pan by spraying hot permeate on all parts of the pan, drain and repeate 3-4 times. If the sugar sand is not all loose I either use a gentle scrub pad or I repeat the heat and wait cycle. It all depends on how much sugar sand is still stuck.
My ratio is 100% vinegar, no permeate. Many however do use a 50/50 ratio. I just never tried adding permeate with the vinegar.
When I'm spraying after the sugar sand is loose, I pump permeate thru my tankless water heater and using a hose spray nozzle I spray the pan with the permeate at about 120-130F. If I shut the spray off I turn the pump off, one time I forgot and the exploding hose sounded like a shotgun shot blast.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.