Wet grinder recommendations?

I have 3 wet grinders and just set up an area to start playing with them,
I have a Secco 4" that I got brand new a few years ago at a garage sale. I tried it out on a practice piece of Petwood a few days ago and was happy with the grinder, and after a few more tries I will hopefully be happy with my work...
I have a used 5" Damo that seems pretty robust as well, but needs the water lines unplugged. I suggest using an inline RV water filter, especially if you have hard water. That should keep the calcium to a minimum. I think the KN is a rebadged Damo, they are identical in shape.
I also have a BD air operated one NIB that I will probably end up selling, it requires a large air compressor to run, and I don't want to fork out a ton of money for that.
My "practice" so far tells me there's a learning curve, and that I need something water resistant that will keep the pieces from moving.

www.amazon.com/SECCO-WV5GRIN-5-Inch-Wet-Polisher/dp/B001KAMAMA

www.amazon.com/DAMO-Variable-Polisher-Countertop-Polishing/dp/B07CV9H4M8/ref=asc_df_B07CV9H4M8

I've been planning on making a piece of plywood with different size holes cut in it with hole saws. Clamp that in a work table to polish thundereggs. I got a Barranca Diamond grinder that works well. I picked it up for $20 at a sell. Considering it has a couple sets of diamond pads and a couple of hard grinder heads, including a never used one with a $115 price tag still stuck on the face of it I think I did pretty good.

I don't know anything about the HP model you linked. It looks like a pretty good deal. I would look at the tool alone and buy the diamond pads elsewhere. Unless those are some great quality pads they are pretty expensive.

I have a regular Makita angle grinder with a diamond cup wheel from Harbor Freight. I also have a Makita Electronic stone polisher that I use with velcro diamond pads. I like both of them.

here's what I used so far, table came in an estate. Unfortunate that I just did a burn barrel last week and all the 2x4 scraps went in.

Hahaha, Thanks. I wish I was as fit as that gentleman was but I had some fun with the Microsoft AI image generator

lapidary1234 I think those angle grinders are great but they do take time and yes in a rock with big holes you can easily destroy the diamond pads. I have done three big pieces with the angle grinder. Two have been pet wood and one was a geode with KY Agate in side. The KY Agate had a big hole and a lot of cracks and ate up the pads abit. All were big and I used a 5 gal bucket with small rock chips and rounded rocks about the size -1/4" by 1/8" more or less. I just pressed the rock into the gravel and and when it got wet it held fine. Only one P wood was bigger that the bucket mouth and hung out to one side but I could still wedge it in the bucket no problem. BTW the bucket had drain holes so as not to fill with water. It takes a while to break in the pads and that took a lot of grind time on the first wood piece. The next two took less time. But you are captive for the whole grind time not like on a vib lap. Also I did not polish flat but did an undulating face on the stones to follow the broken surface. I have plans to polish some fist size Brazilian agates that have been sawn but I have other priorities right now. But the Brazilian agates are set in concrete inside a 10" PVC pipe slab which I cut about 3" thick. Then set it on 1/4" nuts on a plywood plate. I set the Brazilian agates in face to the plywood and poured concrete to the top of the PVC. This gives me a slab about 3.25" thick and the agates stick out one side and can be flatlapped in a vib or set upside down in my bucket of pebbles to hold while I use the angle grinder. hope this helps.