[alt-photo] VDB problem

[John Brewer]

Hello and happy new year,

I'm having a problem with VDB. The solution did have a precipitate but I
read somewhere, (here?), that Sam Wang has microwaved the solution to get
rid of the precipitate. This worked. It was then filtered.

So, I coat the paper with a glass rod and it looks fine. After exposure I
develop in tap water and I get a thin dark brown layer which is very fragile
and shows finger prints if touched and can be rubbed off. Underneath is a
light brown layer, not as dense as it should be. I haven't, and can't at the
moment, test the tap water. Does anyone think this maybe the problem?

Thanks in advance,

John.