Maplenoll platter stability question

Hello Oilman,
My friend did a great job and made a couple of center pins that fit perfectly. Now I want to clean some of the lower platter mounting parts and touch up the paint around the mounting area. I try and restore as much as possible when things are torn apart. My friend thought that the upper and lower plates might have been made of magnesium. They have a very smooth surface where they touch when no air is between them.

Excellent. You should see the difference pretty quick. Couple of points. As you reassemble, please note the bottom plate has the holes that are threaded. As you probably figured out, the long bolt screws into these. Not sure if they are sealed on the bearing surface side but the three tables i have all are sealed. If they are sealed, i would just tighten until they are hand tight. Not sure if you have the white table (lot of plywood that is sealed on sides and top with white corian or the grey table (mostly corian though i believe there is a plywood core. The white table is a little tougher to deal with because with 20 year old plywood, it can be a little brittle. There is a string online where a fellow maplenoll owner completely refurbished the white one and sealed the plywood exposed surfaces with a pliable material that hardened similar to corian. The grey signature table is a lot easier to deal with.

Concerning the material, it is an alloy that i believe has some aluminum and magnesium but it is a special alloy that could be highly polished to extreme tolerances. I have been warned by several experts that you want to leave it alone and do not try to alter it. It is very hard but brittle and was specially polished and each of the plates were matched. I have a few spare platters and spindles that i purchased from the guy i got my ariadne signature. One of those platters is ruined where a person tried to polish it to "improve" it. I know anything can be polished with the right materials but i am a firm believer in leaving that to people who understand how to handle this material. My understanding is that Dilger had a number of these plates made and that was one of the "expensive" components that made the table pretty expensive at the time. i have been very successful just cleaning about every 6 months with an alcohol pad and very soft microfiber cloth. By the way, make sure you put a little lube (the blue stuff if it was provided) in the brass fitting that the teflon pin fits in.

I am excited to hear how this works out for you.

Thanks, again, for your helpful comments, Oilman. I also have the Ariande Signature so the base seems to be a "sandwich" of lead and synthetic countertop material. The long threaded screws seem to only thread so far into the lower platter plate, but I'll heed your recommendations. I cleaned up the thin washers that go underneath the rubber grommets they were stained pretty heavily. Then I'll touch up the black paint above and below the platter support surfaces.
I agree the platter air bearing surfaces should be cleaned only, the material seems already nice and smooth and most importantly flat. I've read about adding another bearing opening to produce a more even lift, but I don't feel I want to tackle that.
I've pretty much done all of the other cosmetic things I wanted to do. Now all that's left is the tonearm rewire, measure the total tonearm moving mass and put it back together and run a few tests.
Cheers!

Some designs do have multiple air ports on the bearing plate but since this design has the air port in middle (not quite center though) adding a second port does not impact the balance as the air pressure is developed in this section and lifts the platter evenly. If the air port was actually on the bearing surface, then you would need several. On the air spindle, it is actually set up with multiple orifices that introduce the air to the spindle. This is to exert an equal pressure on all side of the spindle to get it to float. That is why its critical to keep the pressure high to the arm relative to the platter

Ah, the Maplenoll magic is back! Everything is setup and working beautifully. I have a few more minor things to do, but what great sound this table can produce! Thanks for your generous help, Oilman.