Quote Originally Posted by Ole
All I can say is "give it a try".
And so I did today.

I tried Sprint ammonium thiosulphate-based fixer concentrate diluted 1+2 with water. I figure this is about a 15% concentration. (I called the copmpany but was told the formula was proprietary and they couldn't disclose the actual concentration-Kodak's MSDS for their Rapid Fixer part A listed ammonium thiosulphate content as between 40-50% so I'm basing my guess on that figure.)

Here's the test ambrotype on black glass. It took about 15-20 seconds to reverse the image and clear the plate which is much quicker than hypo. I also think the image appears a little bit warmer than when I use the sodium thiosulphate.

I was very pleased to see this result.