Iss this a flat lap?

Ah...never thought of a velcro type attachment.  Does that usually hold?  I'll try the existing surface of the hub tomorrow to see if it's velcro.  As of now it just feels soft and textured but not quite velcro.  I have some very heavy duty velcro from when I was a teacher and had to keep controllers firmly attached to desks.

I know so little about this stuff and I am a directions reader at heart, no intuition as to the way things work or go together. I assume that under that black foamy cover there is a nut that allows me to remove the plate and do other things with it. The black foam is definitely not Velcro and kind of disintegrating. Looks difficult to remove. Once it's off, what can I put on it. There is another plate just like it with identical black foam on it but in much better shape (the foam). Wish I could download a manual or get a copy, one for a similar machine that would tell me how to work things. I found a water supply kit on the Covington site that looks like it would work with some adaptation.

I don't think this machine was used for lapidary work.  I bought because I got it very cheap, It's a Covington and it's real heavy duty.  I think I will have no choice but to remove the glued on black foam from the underlying "hub".  I figure spatula, razor blade pang scraper and maybe acetone at the end.  I will contact Covington today and hope for answers or a link to a manual for similar machine.

The disk is most likely screwed on, try turning it the direction it turns when is is running to remove it, or there could be a set screw on the bottom side where it connects to the arbor.

Depending on what your plans are for it, I would leave the foam to cushion what ever you are polishing like a soft wheel or expanding drum. If you plan on faceting, that is a different story.

You could try some of the diamond polishing pads they use in the counter top polishing, they use velcro to attach.

That is so interesting! But that also means it could have been used for anything scientifically! For a hail Mary pass you could email McMurdo station, I think that is the biggest American base, and ask if anyone recognizes it! Although, it is coming up to take-over time after the over winter season there so they may be pretty busy! :-)

From what I can see, what I would do myself! Scrape off that gunk off the backing plate. Find some of those velcro discs to the same diameter of the backing disc. That HK site I gave a link to is one possible.

Here are diamond discs with velcro:
www.thk.hk/online-cart.php?cid=36

Here also velcro back diamond discs:
arrowheadlapidarysupply.com/supplies/velcro-backed-diamond-discs/c124?page=2

Here are silicon carbide discs with velcro:
www.gemcuts.com.au/silicon-carbide-disk-200mm-8-inch-velcro-backed

Here are polishing pads with velcro that could work.
silversmithingtools.com.au/shop/lapidary-supplies/flat-laps-accessories/4-x-6-diamond-flat-lap-disks-600g-800g-1200g-3000g-lapidary-tools-jewellery/?srsltid=AfmBOor3f7pGB54ucOQmSzXzDHHWJRhGJpERovkafHobUuJcp2nn3tHM

Not the wet knobbly polishing discs for granite that one would typically put on a wet/dry angle grinder. I do not like them myself, but that is just a personal opinion. I know many folks use that.

I know most of those are in Australia, I only did a cursory quick search! Also, you could actually just buy your own naked diamond discs and even resin impregnated finer discs up to 3000 grit from anywhere in the states, and glue on your own velcro backing to them. 3M double sided tape would work or any glue that can take a little heat.

If you decide to go this way, making them up yourself, what I would do is get the diamond laps and resin diamond laps from somewhere like:
hitechdiamond.com/collections/diamond-discs
Then I would also get the sponge pads along with the resin "diamond smoothing discs". The metal discs do not need the sponge pads, but the resin ones do. So you stick the sponge pad (which already has glue on) to the bottom of the diamond smoothing disc then glue on the velcro underneath that. That way you will have some "give" under the resin pads which will help with rounding your cabochons and taking out any facets from the hard diamond discs.

The set I would get is hard 80 and 180 electroplated (make sure that all of these you buy needs to be without their own backing plates), then 220, 325, 600, 1200 and 3000 grit resin "smoothing discs" (with 5 sponge pads). Then you will also need a polishing pad, also with another sponge pad and Velcro. That should cover everything!

That way you can get from coarse 80 grit right through to 3000 grit and even final polishing in a way where you can change out the grits very easily! And you would have a spare aluminium backing plate.

I keep editing this as I think of more, sorry! You would have to figure out a way to get water to the disc too, all of this will need water. But a gravity fed solution from a higher bottle, or even a little water pump from a water bucket should work.

Hope that gives you some ideas!
Theo

You have all been so much help but special thanks to Theo whalecottagedesigns for your thorough answers. It's taken me a while to get the hang of all this, backing plate, adhesive, velcro, magnetic etc. but I'm making headway. I think the 1" male threads on mine are odd but workable. I look forward to adapting it to accept commonly available lap discs. The water part is easy and I think I'll opt for a pump with two buckets. Thank you all again. Additional hints are appreciated and I think many of us can benefit from this.