Oops! I stand corrected in terms of extra ingredients in Step 4. So much for speculating from the sidelines, sorry...
That info and your listening reports (both Tbg's and Rushton's) do make me wonder though...
Having established that Step 4 is useful, the question remains: what's the optimal time to use it?
Some who know more chemistry than me (which means anybody) have argued that alchohol-containing fluids pose *some* risk to vinyl. You'll both remember the arguments against alchohol presented by Brian Weitzel of RRL (now MoFi). I don't remember that his concerns about the lingering effects of alchohol left behind on PVC were ever reliably refuted. To the extent that any risk exists, using an alchohol-containing fluid as the final step may increase it. Trace amounts not vacuumed off may linger to do whatever damage they may do. This may be a trivial risk, but if it can be reduced...
The four AI fluids we use also include one containing alchohol, but we use that one at an earlier stage. Paul points out that alchohol denatures most enzymes, so we use it immediately after the enzyme solution. We follow that with a surfactant-containing solution, to dislodge loosened contaminants and to begin dilution of any alchoholic residue. The final two stages are rinses with ultra pure water. The idea is to make the progression of fluids steadily purer, which reduces the chances of leaving anything behind.
Step 4 is clearly beneficial. I wonder if it wouldn't be as beneficial or more, and possibly safer, if used right after the enzyme soak. Maybe worth a try, if you care to.
That info and your listening reports (both Tbg's and Rushton's) do make me wonder though...
Having established that Step 4 is useful, the question remains: what's the optimal time to use it?
Some who know more chemistry than me (which means anybody) have argued that alchohol-containing fluids pose *some* risk to vinyl. You'll both remember the arguments against alchohol presented by Brian Weitzel of RRL (now MoFi). I don't remember that his concerns about the lingering effects of alchohol left behind on PVC were ever reliably refuted. To the extent that any risk exists, using an alchohol-containing fluid as the final step may increase it. Trace amounts not vacuumed off may linger to do whatever damage they may do. This may be a trivial risk, but if it can be reduced...
The four AI fluids we use also include one containing alchohol, but we use that one at an earlier stage. Paul points out that alchohol denatures most enzymes, so we use it immediately after the enzyme solution. We follow that with a surfactant-containing solution, to dislodge loosened contaminants and to begin dilution of any alchoholic residue. The final two stages are rinses with ultra pure water. The idea is to make the progression of fluids steadily purer, which reduces the chances of leaving anything behind.
Step 4 is clearly beneficial. I wonder if it wouldn't be as beneficial or more, and possibly safer, if used right after the enzyme soak. Maybe worth a try, if you care to.