This came up in a class with Hugh Phibbs. He pointed out that the problem with these products is How do you get it on evenly? For it to be even you would have to dip it, which of coarse you can't do with paper.
See Hugh, I WAS listening. (Hopefully I understood you corectly.)
I've had trouble with Wei T'O in the past. Clogging, spitting, not spraying. I've had better luck with the Bookeeper spray which United also has. As to how effective they really are (given what Hugh pointed out via framanista ((and Rebeccas' comments too)) among other questions) I sure would'nt claim anything. But if they gotta have it and assume the risks I'd prefer the Bookeepers. At least it's always sprayed for me.
Most papers will tolerate careful soaking, but some will simply disintegrate. The problem is that it's very difficult to tell which papers can suffer soaking safely. If the paper is old, surface soil could cause "tide lines", which may not show up until the paper dries.
And then there's the question of whether and how much the inks will run. The risk of immediate & catastrophic failure is quite high.
And there's more...
A paper sheet's fibers have inconsistent density, and here's why that is a problem: The buffer that slows deterioration is carried into the fibers by an aqueous solution, which will soak more of the buffer into some parts of the paper than into other parts of the same sheet.
Even when the buffer is part of the manufactuiring process, it has limited life in lignin-bearing paper. Like antacids in our stomachs, the buffers become exhausted, and then the discoloration takes place -- later.
When the paper is impregnated with a buffering solution after-the-fact, the eventual discoloration is likely to be spotty. That is, where more of the buffer has soaked into the fibers, discoloration will happen less and/or later, than in areas where less buffer is taken into the fibers.
Personally, I consider deacidification to be a conservator's work.
about 95% of the paper that we would be considering to spray are newspaper clippings of one sort or another.
What we have done is explain what will happen to the newsprint over time... and then have the people go down to Kinko's and have them photo-copy it onto "archival" paper. Then we frame the photo-copy which is very stable, and sandwich the original between Alphacare board with zeolite, and place it in a packet in the back of the frame.
People are very happy for the education and the little "extra" service that we take for them.
I tried an aerosol can of Wei T'O once and it sprayed the first time but several days later- nothing. Whole can wasted. And it was over $30 a can back then!
Brande - zeolites are what is in the Artcare matting and foam boards -they are the little microscopic thingies that gobble up the bad stuff and keep the artwork safe from harm (at least that is the theory...). I am sure someone can give you a much more scientific explanation!