Advancers are easy to keep dry-keep them off cement floors (put a pice of wood down 1st)
do not hose them down who hoses shekves anyway? ( I know someone who did and exploded a few in kiln)
As John says run them thru a slow bisque before glaze firing if damp.
Its just common sense but nowdays it seems in short supply.
I have fired them for more years than can recall with zero issues
THEY ARE MORE FRAGIL THAN OTHER TYPES OF SHELVES-opps caps stuck on but you know this upfront-they do not like uneven quick cooling cycles as well.If you are the type of person always blowing up bisque ware than these may not be for you as you are firing to fast for wares.
if you like quick cooling kilns than these also may not suit you.
If you like fitting more work into a given space and handling less wieght loading (my 1 inch dry pressed 12x24s) wiegh 33# each my advancers (12x24) weigh 9# each-I load 33 to 38 shelves per fire on average say 35 shelves for a 840 #differeance per load-thats per bisque and per glaze fire. Now for me thats at minimum say 35 glaze fires per year so 70 including bisques-thats overe 29 tons a year I do not have to move in shelves alone. Now as far as more pots into a load at less than 3/8 of an inch thick it really adds space to each load that equals more wares in each fire.
The ecomomics only make sense to use them. The pure physical wieght handling adds up to I would have to be crazy not to use them.My only regret is I wish I leaned about them in the 80's instead of the 90's. My back would be in better shape as I do not like moving tons more than I have to. Mine are long paid off. If I was a hobbist these make less sense but I'm not. If pottery is your living than these only make sense.
Add the fact that I can pick one up with pots on it (12x24) and glaze does not stick to them and they NEVER warp EVER well whats not to like.
Oh I cannot wash them in the dishwasher darn. Always something
I have had a few PMs on these regarding firing a few times a week at art centers and thats where thse shelves really shine.