Does the Step 4 final rinse for Walker Prelude help?

Tbg,

Good report, though I doubt it contains what most people normally *think of* as dangerous chemicals. I expect Step 4 is just a still more highly purified water. After all, would you want anything else for your final rinse? The goal of perfect cleaning is to leave NOTHING between stylus and vinyl. The sonic improvements you described are evidence that Step 4 is doing exactly that.

That doesn't invalidate Walker's label warning. Drinking very pure water like that sold by Walker, AIVS and MoFi (soon, it's in beta testing) would be quite dangerous. Being such a good solvent it would leach tissues of many compounds that naturally occuring water does not absorb, compounds your body needs. Drinking laboratory-pure water is something no one should do.

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.

HDM and Mark,

My local materials scientist tells me that certain alchohols will decrease the surface tension of very pure water relative to a PVC surface. This may allow Step 4 to flow more readily deep into groove bottoms and tiny modulations than pure water would do. That might explain the results Tbg and Rushton have heard, which I trust to be real. Neither of these gentlemen has ever posted anything that wasn't honest and helpful for as long as I've known them.

My question was based on the fact that the lower the surface tension of a fluid, the more difficult it becomes to remove a thin film of that fluid from a surface. Any combination of fluid, wetted surface and RCM involves a conflict between the surface tension between fluid and surface and the air velocities produced by the RCM. For any given air velocity, the lower the surface tension, the more fluid will be left behind.

Tbg and Rushton's results and Walker's explanation all make perfect sense. I only wondered (perhaps somewhat academically, as Rushton suggested) about the risks of alchohol traces and the possibility that an alchohol step immediately following the enzymes might be useful. Those questions remain, but it's beyond my knowledge to do more than pose them for anyone who's interested to consider.

Doug

P.S. to Mark, neither Paul nor I had anything to do with designing the AI fluids. They were in the finished form we know today several months before we first saw them. Jim gets 100% credit for the redesign. We're just satisfied users like you or anyone, with no other interest.