Due to some trim work, I need to shave off several 1 in x 3 in x8 feet boards.

I need to shave off the 1 in thickness by 3/8 inches EXCEPT for a rectangular of 1 in x 7 feet, with one side shared with the board. In other words, I need to shave off in a U shape three sides of the board. This is so it would fit into some door jambs.

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What is the best and safest tool to achieve this, even if somewhat time consuming? Would a wood router do this, and if so should I get plunge or fixed-base?

I'd prefer avoid using a table saw due to various factors including cost.

  • 3
    Can you add a photo or diagram of what you're intending to do? It's difficult to follow your description. If you don't have the reputation to embed a photo in your question, upload it to a free photo hosting site like imgbb or imgur and we will edit it into your question. Commented Mar 4, 2021 at 14:48
  • 12
    Also, be sure you're not asking an XY question. It may be better to ask about your actual problem, and not a proposed solution.
    – isherwood
    Commented Mar 4, 2021 at 14:58
  • Routers are usually for shaping wood instead of cutting. An inexpensive power saw will be as much or less than a good router.
    – crip659
    Commented Mar 4, 2021 at 15:08
  • 1
    It may be more suitable to modify the door jamb? By trimming off the lump, then your new wood will fit flat and also hide any marks. Comment because doesn't answer the question as asked.
    – Criggie
    Commented Mar 5, 2021 at 11:22
  • 2
    Are your boards actually or nominally 1" thick?
    – isherwood
    Commented Mar 5, 2021 at 15:54

4 Answers 4


If I had to do this, I'd just plane down the entire boards on a thickness planer, cut a 3/8" x 1" x 7' board and glue it back in the desired place. If you don't have a thickness planer, maybe a friend does or maybe a mill shop in your area would do it very inexpensively. A 18 ga nailer with 3/4 nails could be used to hold the 1x7 in place while the glue dried, or even a bunch of small screws.

I know I'm not answering the question you asked, just suggesting an alternate approach.

  • 8
    +1, But you're a bigger sucker for work than I am. I would just go buy a 5/8" thick board to begin with. Besides, if OP doesn't have a table saw, they probably don't have a thickness planer either.
    – J...
    Commented Mar 5, 2021 at 11:49
  • @j Yeah, I wondered about that as well, which is why I suggested maybe a friend into workworking or a local mill. Also, the wood boards he has now might not be available in 5/8". Commented Mar 5, 2021 at 15:52
  • Sure, but this isn't a DIY solution. It's a pay-someone-else solution. Not many of us have friends with planers in their garages. It's also much more time consuming, considering discovery and travel.
    – isherwood
    Commented Mar 5, 2021 at 15:55
  • @isherwood Actually I have quite a few friends with wood shops of various capabilities. If you really want a DIY solution, a hand held powered plane might make short work of it as well. THey aren't that expensive. Commented Mar 5, 2021 at 16:01
  • I'm not sure how that counters my statement that not many of us have such access to wood shops. Obviously the OP doesn't.
    – isherwood
    Commented Mar 5, 2021 at 16:03

Circular saw table adjustment to the rescue. If you don't already have a router bit this is a good solution. Otherwise, a router would do fine. You'd need a straight bit without a roller tip.

This technique is easy and relatively fast. It doesn't require removing safety equipment from your tools.

  1. Set your saw's table to the depth of the material to be removed. Make a test cut to be sure it's accurate.
  2. Mark your board and make the first cuts around the 1" strip to be left.
  3. Make cuts across the board every 3/8" or so, leapfrogging small strips. This is to keep a level cutting surface for future cuts.
  4. Where you can't cut all the way through to the 1" strip, make similar cuts lengthwise on the board.

At this point you should have a completely striped (sliced) board over all areas outside the 1" strip. You have a couple options to continue:

  • Knock all the remaining ribs off with a hammer and chisel. They'll practically fall off due to the cross-grain connection. Shave down any lumps with the chisel.


  • Slide the circular saw sideways from one end, carving away the ribs as you go. You'll need to make several passes to clear the entire width of the board. This is a very effective technique, but requires more advanced tool control.

Use eye and ear protection, of course.

  • Would a router attachment to a drill be enough?
    – Manu
    Commented Mar 4, 2021 at 16:20
  • 2
    No. Wrong tool for the job. You'll have no way to control depth or angle, and most drills aren't fast enough.
    – isherwood
    Commented Mar 4, 2021 at 16:21
  • 1
    This is an absurd amount of work - dado-ing a whole eight foot board on a table saw feels more like a cruel punishment than a satisfying day's work. 0_o
    – J...
    Commented Mar 5, 2021 at 15:49
  • 1
    Or just buying a 5/8" thick board in the first place?
    – J...
    Commented Mar 5, 2021 at 15:51
  • 1
    The same place you buy the 1" thick board from? Wood shops here serve plenty of standard sizes.
    – J...
    Commented Mar 5, 2021 at 15:53

Lay out three of the boards side-by-side with a gap, e.g. 1/2", between them. With the outer boards for support use a router to make multiple passes down the center board until you have reached the desired thickness. (The gaps allow you to run of the edges off the center board without sacrificing the guide boards.) A bit of cleanup, e.g. with a random orbit sander, will probably be needed.

If your router base isn't large enough to straddle the outer boards you'll need to extend it, e.g. by attaching a suitable piece of plywood.

Depending on the number of boards to be processed you may want to make a guide board with spacers for the gap and a fence for the area to be left at full thickness.


On condition you haven't yet bought the board, buy two boards, one the thickness of the lower part, the other to make up the total thickness. Then simply cut out, with a jigsaw, the top board.

This doesn't directly answer your question, but solves your problem.

To answer the question, a router will do the job - but it's messy and time consuming.

  • This just seems to repeat George's answer from yesterday.
    – TylerH
    Commented Mar 5, 2021 at 15:00
  • @TylerH - George suggests planing down the board. My idea is to not do that - but instead use two boards of differing thicknesses. Cutting out the problem of any planing. Which OP most likely doesn't do anyway.
    – Tim
    Commented Mar 5, 2021 at 15:05

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