I am installing new butcher block-style counters in my kitchen. The new sink has a flat flange around the edge. (It is made to work as as undermount or a drop-in.)

I want to drop in the sink. Ideally, I'd like the top of the sink flange to be flush with the top of the counter. I'm wondering what is the most precise way to shave 1/16" (or less) of the countertop down.

I figured I would drop the sink in its cutout, then use a utility knife to trace around the flange. Then remove the sink, and shave down the counter between the scribe mark and cutout. Any tips on how to remove just a tiny amount of countertop?

A router seems like more tool than you want in this situation, but maybe it could be adjusted to make such a shallow cut?

A chisel seems like it would be hard to control for such a shallow cut.

Do I want to use a hand plane along my knife edge?

Background: My butcher block is from IKEA. It has a beautiful walnut herring bone pattern. Over particle board. The veneer is plenty thick, and my kitchen sees more microwaving than baking from scratch, so I think it will last just fine. But under-mounting the sink isn't an option.

  • 1
    I thought that undermounting the sink would leave more wood exposed to more water. When I'm ready to set the sink for good, I plan to use masking tape all around the edge of my recess to catch the squeeze-out, then set the sink with a good amount of silicone under the flange. In truth, I could just set the flange on top of the counter, I just thought it would be a little more luxurious to not have the tiny lip of the stainless flange. Commented Feb 27, 2020 at 20:16
  • 1
    Since nobody else has said it already Liz welcome to StackExchange. If you're going ahead with the power router option (what I would have advised also, ideal job for one) something to be aware of before you start is trying to make sure as little of the router base is unsupported during the operation, if it is it might lead to it tipping and the creation of a low spot. In reality as long as the main field of the 1/16" rebate is even those won't be an issue as the flange will cover them (so it's not a visual concern) and it'll bridge the gaps no problem as long as they are few and far between.
    – Graphus
    Commented Feb 28, 2020 at 7:46
  • 1
    [contd] If it does happen that the rebate is more uneven than you'd like no need to panic, you can use a wood filler to fill divots and level the surface if need be. The ideal filler for this purpose would be an epoxy 'tootsie roll' type, since that'll be completely waterproof. Obviously you hope water will never get in under the lip with the generous amount of silicone you'll use to bed the flange down, but one can never be 100% sure. Epoxy will give you peace of mind that the fills won't be negatively affected in case that happens at any point in the future.
    – Graphus
    Commented Feb 28, 2020 at 7:52
  • 1
    Graphus - thanks for the tips. Yes, I had already decided not to panic if the recess isn't mirror-flat!. Also, I think I will scribe the outline of the flange with the sink upside-down. I can make the cutout after I do the routing, to have a good solid surface for the router. Here's a new question - How much depth should I allow for silicone? Any? If I take off material exactly for the depth of the flange, then the flange may be a little proud once I put the silicone down - Right? Commented Feb 28, 2020 at 16:12
  • 3
    Have you done this yet? DON'T FLIP THE SINK TO MARK THE OPENING. It's possible that the sink is absolutely symmetrical, but not even remotely guaranteed. Cut the hole, drop the sink in and mark from there. Commented Feb 29, 2020 at 14:24

1 Answer 1


A router would be the normal tool to use for this. You could also use a router plane if you prefer hand tools.

Scoring a line around the outline of the flange is a good idea. Cut out most of the waste with the router then clean to the line with a sharp chisel. Referencing the chisel on the flat left by the router should let you continue the flat surface very accurately.

You can set the router to the exact depth of the sink flange by first "zeroing" the depth by putting the base on a flat surface and plunging the router bit to touch the surface. Then capture the flange between the router's depth stop and the turret the depth stop hits. Lock the depth stop, then when you plunge the bit will be exactly the depth of the flange.

Since you're not removing much depth you can use a larger bit to get a cleaner bottom surface.

  • Thanks. I'll try this over the weekend and report back. Commented Feb 27, 2020 at 20:35
  • @LizinDallas I am waiting with baited breath for the "report back" Were you able to rabbit in the veneer ?
    – Alaska Man
    Commented Mar 3, 2020 at 19:12
  • 1
    Just FYI I wrote this answer before the info about it being veneer over particleboard was posted. I don't think this changes anything about the routing but it will make the chisel work a lot less "clean" as the small chips of wood will likely pull out instead of severing. Normally with solid wood I'd just push the chisel in, but with particle board I would use more of a "slicing" motion. Also make sure your score is deep enough for the horizontal cut to hit it. Particle board won't "pop" off the same way solid wood does if your cuts don't quite connect. Commented Mar 4, 2020 at 0:42
  • 2
    Thanks to everyone for all the great tips. The sink looks great. The routed section was shallower than the veneer, so the particle board did not pose a problem. I'm very glad I did not make the cutout first - It made the router much more stable. I checked my sink, and it was symmetrical. I flipped the sink over to mark the outline for the router. Instead of chiseling the last bit, I just routed right to the edge (I kept moving the fence to sneak up on the edge.) The routed edge is super clean. Thanks! Commented Mar 4, 2020 at 16:34

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.