Sweating Stone

[Barrabas]

Hi,

Just got a Combo(coarse/fine) Carborundum aluminum oxide stone a few minutes ago from a local distributor, and the weirdest thing happened..

I left it in the seat of the car (in the sunlight approx. 70 degrees)to grab a sandwich, was gone approx.45 minutes, when I got back in the car I noticed there was a layer of moisture completely covering the fine side of the stone.
It was actually standing on the stone - not enough to drip off, but pretty close to that amount - really weird.

At first I thought it may be from where the stone has sucked in moisture from the dark warehouse, and when I set it in the Sun - it drew it out.

The moisture is clear, has no real scent, but it is kinda oily, so I'm not sure if I should leave it to let it sweat?

Or if I need to get it out of the light - maybe it's a vampire stone

Any thoughts?

 

[G3]

Sounds like oil from the stone is bleaching out from heat or if it is water, possibly from the same reason. I would guess that if the stone was lightly oiled and stored in a cool, dark spot the oil will remain thickened but once heated will bleed out. I seem to remember this happening on stones I overoiled and store in my shop near some heating pipes. If it's water then I'd be concerned how much is in the stones for them to do that. I don't think it matters either way as to the performance of the stone.

 

[yuzuha]

Most of those stones are manufactured with a little oil in them for lubrication for those who like to use them dry. Probably just expanded due to the heat and seaped out a bit.

 

[cbwx34]

These stones are pre-filled with oil, so that when you oil them, they don't just soak it up.

I've found they pretty much have to be used with oil... or they will clog. They're not pre-lubed so that you can use them dry, they're pre-oiled so they won't just soak up the oil that's applied. (That's according to their literature.) YMMV.

cbw

 

[yuzuha]

Yeah, you're probably right for the larger bench stones. I was reading about tool and die-makers stones and some of them are oil impregnated so you don't have to use stoning oil to lubricate them (though it still helps).