I took my solo apart to clean out the AVB and when I took apart the bowl I found this hard white material on the side of the stainless steel bowl. I am assuming it is not safe to still use. Am I wrong?
No problem, except you should never, ever, take those screws out again.
That 'hard white stuff' is
furnace cement. The top cover, cup, heater and so on are glued together with it. It's been there all along and is necessary. Notice the four tiny wires inside the Teflon tubes coming through the slot? The larger two are the heater, the smaller the temperature sensor, break any of them and you've killed the Solo. If it's too short to solder back together it can't be fixed.
No need to ask me how I know this........
Very carefully put the screws back in, don't worry about t he clips that are there to protect the leads as a sub assembly, snug it back up and don't mess with them further is my advice. Owners are not supposed to be tampering in the area. Hopefully it's still operational.
Edit 2
@TheSandyLorax , looks like contact oxidisation and not in the vapor path. It should clean off with a cloth dampened with hot water. If that works, then apply a thin coat of petroleum jelly to prevent reoccurrence.
Bad advice, IMO. Don't tamper with it, and for sure keep the Vaseline in the bathroom/bedroom where it belongs. You don't want it on 400F surfaces and it will serve no useful purpose.
Put the screws back and don't wiggle anything until you do. The protective clips aren't protecting you at this point. BTW, don't freak at gaps between the top and bottom (plastic) covers, that's normal as well. Just put the screws back toot sweet....... And consider yourself lucky, if you still are?
OF