I want to install a reverse osmosis water filtration system under my kitchen sink. It has a separate faucet for which a hole needs to be drilled in the counter top.

I have never drilled a countertop before. How hard is it - or I should ask how easy is it to screw it up? Should I do it myself or call in a pro?

Not hard with the right bit.
Get it started first with a small bit to keep it from wandering then use the size you desire with water.

You'll probably need at least a 1" hole, I'd wait until you get the RO system in hand to determine the size needed (go a little larger than required).

Use a diamond hole saw bit. And keep it lubricated/ cooled with water. Some people make a dam around the target area after establishing the hole start and fill with water during cutting.

There are surely plenty of videos outlining the process on YouTube.

I used a diamond hole saw from Amazon to drill for my RO faucet. Take it slow and keep it wet, piece of cake.

For something where appearance is important, you want to cut stone by friction/abrasion. A drill or auger will chip it all to hell, I would think.

quote:

Originally posted by mark60:
I used a diamond hole saw from Amazon to drill for my RO faucet. Take it slow and keep it wet, piece of cake.

This.

Diamond hole saw drill bit. Start at an angle to get it started, one side of the drill bit cutting. Once it starts to cut into the granite slowly move the drill to 90 degree angle as you drill.

If you start at 90 degrees the bit will not bite into the granite but move around making a mess of your countertop. Go slow

I’d rather pay someone who knows what they are doing than ever attempt to drill my counters but that’s just me.

A while back I seen a kit at the pawn shop. It was a shallow dish with adhesive on the back and a 1" hole in the center. It came with a 1" diamond hole bit. Apparently you stuck the dish on the granite, filled it with water and drilled thru the hole in the dish filled with water. I thought "I should get this" but how many times would it ever drill a hole in my granite top.
A few years ago I did add an RO system and used the hole already there for the under sink soap dispenser.

I had a guy do it in our granite countertops in our RV (minimal tools). About 15 minutes if I recall. I installed the RO system myself.

After securing your tools, I'd visit a countertop cutter business, buy a couple scrap pieces of similar stone, and practice. You're probably better than me, bit I usually learn something pretty important practicing on things that I can't afford to screw up. After that if I'm not gtg I hire a pro.

It's a shame you can't run the water line through the cabinets to the refrigerator tap.

quote:

Originally posted by bendable:
It's a shame you can't run the water line through the cabinets to the refrigerator tap.

This is what I did. I put a "Tee" the RO out line, one to the sink RO faucet and over to the double door fridge for the ice maker. No more stanky ice cubes in places with questionable water.

quote:

Originally posted by PASig:
I’d rather pay someone who knows what they are doing than ever attempt to drill my counters but that’s just me.

I'd do the same, contact someplace that installs granite counter tops and see if they'll come out and drill your hole for you. If you mess it up its messed up for good so no room for errors.

When I remodeled my kitchen the only thing I didn't dare attempt was installing the granite counter top. I didn't have the expertise or tools so I was happy to pay a pro to do the work for me.

Agree that calling around to get someone to do it that has the tools and experience might be a good idea. A new countertop if it cracks or chips is expensive compared to getting a pro to do it.

Link

How to Drill Holes
Step 1:
Determine the size of the hole and the location you are drilling. Measure twice, drill once. It goes without saying that once you determine the size of the hole you should prepare a right sized drill bit for the job.

Step 2:
Mark the area that you will be drilling. A marker or sharpie dot may be enough for smaller holes. Use a template for larger holes. Take your time in marking properly as drilling on granite affords you no second takes.

If you are concerned that the drill bit will slip, you can clamp scrap wood over the area to be drilling and place a marker on the wood. This ensures that the drill bit will not be wobbly when it reaches the granite.

Step 3:
Clamp scrap stone directly underneath the area to be drilled. This prevents chipping on the granite. Make sure you clamp on both sides of the stone to ensure stability.

Step 4:
Securely install the right sized drill bit on the drill. Any loose attachments may end up in a nasty hole, not to mention the safety hazards it poses. Also, make sure that the drill bit is designed for granite or natural stones and has enough depth to go through the stone. A diamond core drill bit is recommended if available.

Step 5:
Place the drill on top of the marked location and apply light pressure. Let the drill do its job. Drill at a steady speed until the drill bit makes a deep enough mark on the granite. Then you can carefully speed up from there. You may drill with water or drill dry. If you do choose to use water, you can make a pool around the marker with putty.

Step 6:
Continue drilling until you reach the scrap stone underneath. When drilling for multiple holes, make sure to let the drill bit cool before starting to drill the next hole.

quote:

Originally posted by smschulz:
Not hard with the right bit.
Get it started first with a small bit to keep it from wandering then use the size you desire with water.

This and tape the counter with good tape where you are drilling the hole and beyond, the tape will help keep it from cracking.