Selenium toner causing paper stain - why?

With the arrival of fall, I'm finally getting around to doing some of those tests that we all promise ourselves to do - someday. I wanted to arrive at a standard time for toning, so I made five identical prints on Oriental Seagull #2 fiber based paper, then processed all of them the same except that one was left untoned and the remaining four were toned for varying periods from 2 minutes to 6 minutes. Here's the precise process I followed:

Develop (Dektol 1:2) 2 min
Water (not stop bath) 1/2 min
Fix 3 min
wash/hold
Plain hypo 3 min
Selenium toner 1:15 with a little balanced alkali - varied times
Kodak Hypo Clearing Agent 3 min
wash

There was no rinse between toner and HCA. As soon as I put the prints into the HCA, a orangish/sepia precipitate started to form which eventually has stained the fibre base. This has occured to me before and seems to usually happen when the toner and HCA are fresh.

Can anyone explain this and suggest how to stop it?

I'm familiar with Ansel's method of mixing the toner and HCA together, but have read conflicting reports about the efficacy of that approach, so have tried to standardize on the separate baths.

Many thanks for any suggested fixes.

Bruce -
While the "classic" textbooks talk about going directly from the fix to the toner, my experience is the same as yours that this almost certainly guarantees staining.

The process sequence that I use and that does not cause staining is:

developer
acid stop
rapid fix
rinse/hold
hypoclear
toner
hypoclear
wash


The second trip through hypoclear is required because selenium toner contains ammounum thiosulfate.

Quote:

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Originally Posted by Louie Powell

Bruce -
While the "classic" textbooks talk about going directly from the fix to the toner, my experience is the same as yours that this almost certainly guarantees staining.

The process sequence that I use and that does not cause staining is:

developer
acid stop
rapid fix
rinse/hold
hypoclear
toner
hypoclear
wash


The second trip through hypoclear is required because selenium toner contains ammounum thiosulfate.

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I use the same process as Louie except I add a 1 minute rinse between the hypo clear and toner and I don‘t use the second hypo clear. I do use a I hour wash even though I use the rapid fix The water bath between hypo clear and toner extends the life of the toner. Haven’t had any stains in 20+ years of using this system
Jerome