6

I have a bookshelf with a plywood back, the plywood is 3mm thick. The bookshelf is against a power point so I want to out a rectangle to allow the power cords to get access to the power point when needed.

How is the best way to cut it out? What tool should I use?

Edit* The rectangle does not need to have sharp corners. It just needs to be clean looking and provide access to powerpoints

13
  • 4
    One way is to drill a hole, then use a jigsaw to cut out the opening you want, starting at the hole. You could also use a router to cut out the opening from the hole.
    – Armand
    May 23, 2022 at 23:30
  • 3
    What tools do you have? Can you move the bookshelf out or do you have to work on it in place? May 23, 2022 at 23:31
  • 3
    On many shelves in the last 20 years or so (especially the type you buy in a package and assemble yourself at home) will have a cheap paperboard back that has a printed surface to look like wood.
    – Michael Karas
    May 23, 2022 at 23:44
  • 2
    If the back is actually cardboard, as noted by @MichaelKaras, then a simple utility knife is all that's needed. As you can see in the answers you have so far, the proper tool depends on whether the book shelf has been installed already or if you're still in the planning stages. It would help if you would edit your question to indicate whether it's currently full of books or not.
    – FreeMan
    May 24, 2022 at 12:18
  • 2
    Once again, location is important for good answers. The hole size for UK plugs will be substantially larger than that of, say, Continentals, which could get away with a round hole (hole-saw), which won't do such a good job in UK.
    – Tim
    May 25, 2022 at 8:26

4 Answers 4

18

I've often done this using a jigsaw, with the bookcase face down, or before assembling it. I assumed you want sharp corners - jigsaws can cut fairly tight turns but not sharp. I wouldn't run the saw along a fence for this, though you could.

  • Mark out the cutout on the back
  • Drill a hole bigger than the blade (10mm or 3/8" works well) near but not at one edge.
  • Saw, forming a smooth curve to meet the side, ending at a corner (maybe turn a bit sharper than I've drawn, but it's not to scale.
  • Take out and reverse the saw to finish that side
  • To cut the other sides, back the saw away from the corner, and make the turn onto the new side.
  • Again, cut into the corner by turning the saw round.

You may need to sand a little where the cuts from opposite directions meet, but with practice that shouldn't be needed.

cutting out a rectangle with a jigsaw

Jigsaws give the nicest finish if you work from the back, because they cut on the pull stroke so any tearing out is on the face you're working from. The sole blade can also leave marks.

Here's one I did with a jigsaw, to fit a UK double socket (but I've since moved the bookcase to another place).

cutout in ikea billy bookcase

That's Ikea Billy, so a reasonable particleboard with a fake wood veneer.

6
  • Well described, and exactly what I would do.
    – FreeMan
    May 24, 2022 at 12:16
  • To the user who suggested an edit about cutdown blades - it wasn't clear, but if you explain in a comment I'll try to incorporate it. Those I've seen won't help with tear-out as you seem to suggest, but might help with working in a confined space - indeed, metal-cutting blades work fine in thin board if used gently and are shorter than wood blades
    – Chris H
    May 25, 2022 at 10:08
  • 1
    Depending on the material the back is made from, one possible finishing touch would be to cover the edges with black tape (electrical or gaffer's tape would work, but needs to be wide enough to go around without peeling off). This can help cover any slop if you're not super-skilled with a jigsaw. The trick is to wrap the tape so that most of it is on the back and you have a nice, even line on the front, say 1 cm wide (or 1/2" depending on your choice of units). Works best if the original material is already a dark color on the front, but when cut you can see the lighter edges inside. May 25, 2022 at 13:27
  • I've done basically the same thing except using a drill bit on a Dremel using a shield that sets the depth of the cut. I trace the line with a pencil and then poke in the corner and trace around. I've got this one: smile.amazon.com/gp/product/B0000302YS
    – StalePhish
    May 25, 2022 at 14:55
  • @StalePhish I've never really like those rotary cutting bits for straight lines, unless running against a fence. They're too willing to curve. But I haven't had one that you can hold as nicely as the one you linked
    – Chris H
    May 25, 2022 at 14:58
13

The almost optimum tool for cutting a hole like this is the oscillating type saw. You can get these into a fairly tight spot and with control of the tool you can avoid damage to the wall or power point sitting behind the shelving unit. Other solutions such as a jig saw can cause damage behind the shelf unit unless you move it away from the wall before cutting.

6

A recently developed tool for oscillating drivers is this tool. I know product recommendations are off topic here, but I couldn't resist passing this info along. It's intended for sheetrock, but would probably work OK with 3mm plywood.

box cutting tool

11
  • 7
    At that price, you'd have to use it for more than just a one-time bookcase fix to make it worthwhile. May 24, 2022 at 3:04
  • $72 so you can cut four sides at once? You can buy the whole oscillating saw tool for less than half of that. harborfreight.com/…
    – gnicko
    May 24, 2022 at 3:05
  • 5
    @gnicko Harbor Freight is Chinese crap. The most expensive tool you'll buy are cheap ones that you'll have to replace 5 times. The OP can make his/own decision as to whether this is an appropriate tool for him and the future. Don't dis on me just BC I suggested what I think is a way cool tool that could help a newbie do a good job. May 24, 2022 at 4:13
  • 4
    Could be a cheaper option for some who might do a lot of damage with other tools suggested :)
    – Solar Mike
    May 24, 2022 at 9:36
  • 3
    @GeorgeAnderson some HF is Chinese crap. Some is actually pretty decent. Granted, my standard is to not buy power tools there, but I've purchased hand tools from them, had a couple break, and simply walk in with the broken one, pick up a replacement from the shelf and after 3 minutes of fumbling at the check out register, I have a functional replacement, free of charge. Their quality is getting better. Also, if you know what you're getting into when you buy there, then a 2nd use of the one-off tool is a bonus! </OT product/store recommendations>
    – FreeMan
    May 24, 2022 at 12:14
2

Best would probably be a router. Using a template to be sure the hole is nice and neat. You can get less expensive small routers (for most intents and purposes) as "laminate trimmers" and "cutout tools" - heck, you can get a router base for a Dremel (-type) tool and that would be adequate for this little job.

There are many other ways to get there.

8
  • Unfortunately, making an accurate template for the router is a skill in and of itself. I've made one or two and don't have enough practice yet to make them well. Maybe there's a trick that I need to learn...
    – FreeMan
    May 24, 2022 at 12:11
  • For something like this, it's trivial. Plain old rectangle. Measure from the edge of the router baseplate to the closest side of the bit. Attach 4 boards to the workpiece that far from where you want the edge of the hole, typically with double-stick tape. [Can do the same thing with less offset using router collars, or no offset using a bearing guided bit.] Run the side of the router baseplate against the edge of the boards, and like magic you have a nice clean hole with rounded corners (the radius of the router bit.)
    – Ecnerwal
    May 24, 2022 at 12:20
  • Hard to get a tight, right-angle corner with a router...
    – MikeB
    May 25, 2022 at 15:13
  • ...And why would you need or want one for an access hole? But if you do, a minute or two with a file would do the trick on 1/8" plywood.
    – Ecnerwal
    May 25, 2022 at 15:15
  • Given the nature of the question, it's clear the asker doesn't have a whole workshop full of tools. Almost everyone has a drill, much less likely to have a jig saw. Almost nobody has a router, so while this answer may be accurate, it's not very helpful IMO. Jun 1, 2022 at 20:18

Your Answer

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

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