Reddit mentions of Diamond Polishing Pads 4 inch Wet/Dry 8 Piece Set Granite Stone Concrete Marble

I just did our counter tops a few months ago and boy do I have a lot to say on this. It's going to be a long post and I'm on mobile so bear with me on this. I'll put links to all the stuff I used at the bottom.



I bought concrete specifically designed for countertops. I absolutely suggest getting a bag and doing a test run. It doesn't have to be a huge piece, but you want to make sure you follow the directions exactly the way you would to make your actual countertops. Use the same form material, the same water to concrete ratio, the same mixers, the same polishers, etc. This way you can plan appropriately. My concrete mix was stupid dry. Like wet sand consistency. If I'd known that would happen I would have found an add mixture to make it flow better, but instead I was stuck trying to make due and it shows in my counter. Another point, don't just add water until you get the consistency you want. Adding too much water will weaken your concrete and it will crack easier



I did cast in place. I put tile backer board on top of the cabinets and built my own forms with melamine. I suggest, if at all possible, do pre-cast. This gives you a better surface to start polishing from and you don't have to worry about getting the back side perfectly flat, you can use the flat side from the bottom of the form. You'll need some kind of reinforcement in the concrete, you can use steel wire, fiberglass mesh, or you can add fiberglass directly to the concrete mix. I used fiberglass mesh, I think it was easier than steel wire and I didn't have to worry about adding stuff to my concrete mix.



For finishing, I bought a cheap Harbor Freight variable speed polisher and diamond polishing pads from Amazon. I wet polished the crap out of the countertop. WARNING: the HF polisher is not meant for wet polishing, you could shock yourself. You have to evaluate the risks yourself and decide if this method is appropriate for you. I decided that useing just enough water to keep the surface wet, and keeping the polisher as dry as possible was good enough for me.



For sealing, there are two routes you can go. A penetrating sealer, like wax and oil, or a barrier, like epoxy. Penetrating sealers are cheap and hard to screw up, but they don't provide the best protection. When people complain about staining on concrete countertops, they probably used penetrating sealers. I chose a two part epoxy sealer that I could roll on. It turned out great and so far I haven't had any problems, including zero staining from wine, coffee, and oil. Make sure to read the instructions for whatever you choose and follow the directions to the letter.



Links:

Concrete: http://www.kingdom-products.com/product/imperial-countertop-mix/


Fiberglass mesh: https://www.concretecountertopsolutions.com/product/fg50-fiber-mesh-reinforcement


Sealer: http://www.surecretedesign.com/product/concrete-countertop-sealer/amp/


Melamine: https://m.lowes.com/pd/Actual-0-75-in-x-49-in-x-8-08-ft-Premium-Melamine-Board/3605066?cm_mmc=SCE_PLA-_-LumberAndBuildingMaterials-_-ParticleboardAndMdf-


Tile backer: https://m.lowes.com/pd/James-Hardie-0-25-in-x-36-in-x-60-in-HardieBacker-Fiber-Cement-Backer-Board/999994576


Polisher: https://m.harborfreight.com/power-tools/polishers/7-in-10-amp-variable-speed-polisher-62861.html


Polishing disks: https://www.amazon.com/dp/B071ZTFYYX/ref=cm_sw_r_cp_apa_YrJUBbPQFD33Z

They can be polished out. You can either do it yourself with a kit like this (note that I haven't personally purchased this kit, so I can't speak to its quality) or hire it out. Any reputable granite contractor in your area can do the job, and it would be substantially less expensive than replacement.

Unless you have prior experience with polishing (be it automotive or otherwise) or are willing to take the chance on your countertops (or at least a small section), I'd recommend hiring it out.

I can tell you my setup that works pretty well for a DIY-scale operation. I bought this variable speed polisher from harbor freight

https://www.harborfreight.com/7-in-10-amp-heavy-duty-digital-variable-speed-polisher-62297.html

From there, you'll want to get a set of diamond polishing pads like the ones here:

https://www.amazon.com/Diamond-Polishing-Granite-Concrete-Marble/dp/B071ZTFYYX/ref=asc_df_B071ZTFYYX/?tag=hyprod-20&linkCode=df0&hvadid=216531060403&hvpos=1o1&hvnetw=g&hvrand=15897563041150168640&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9052441&hvtargid=pla-351492880558&psc=1

You'll take off the head that's comes on the variable speed polisher and put the one that comes in the set you get with the polishing pads.

You'll next just want some sort of water source to wash off the dust and debris that accumulates while you are polishing. I made a watering system where I took two five-gallon buckets, put one on top of my table and the other at the bottom. I cut a hole and put in a PVC pipe and put a faucet on it. I put the water in the top one and turn on the faucet just slightly so the water drops into the bucket below. It still splashes water around so I usually drape a towel over myself. You can get good results by just washing the rock off in a basin every 10-15 seconds.

Polish the rock for as long as you'd like on each level. I usually start off with the speed setting on like 20-25 on the rougher grits (50, 150, 300) to really get it leveled. As you go up in grits (500, 1000, 2000, 3000), I'll usually slow it down to like 10 or 15. Take your time and you can get rocks looking really really nice and shiny.

If you really want to red-neck DIY it up, you can also buy their tile saw and cut rocks by hand.

https://www.harborfreight.com/7-in-portable-wet-cut-tile-saw-69231.html

This was great for me when I was geode hunting. There are some youtube videos showing people cutting the rocks by hand. The blade isn't sharp, so you just want to be careful and wear gloves/eye protection. There's a basin of water underneath so it does splash everywhere. I used a tarp against a wall in my garage and was able to catch most of the water and have it trickle down back into a bucket. With some practice, you can cut rocks flat enough to use your low-grit polishing pads to really get them flat.