# Advice on Cable Grommet Techniques



## plunger (Jun 21, 2013)

Hi!

I need to install a cable grommet in the top surface of one of my projects. I've seen some of the commercial grommets, but I can't say that I'm overly impressed with the perceived quality or hide-ability. Some are plastic, some metal, and then I'm concerned about flush mounting them and coloring them to match.

I'm thinking about making a removable grommet out of the 3/4" wood top itself. Considering the use of hole saws & routing a lip. I'd be OK with a rectangular insert as well. Not exactly sure how I'd cut this part out such that it's a tight fit with minimal seams.

Once the insert is done, I'd drill out some holes for the cables to pass through. I'd like to have a second insert made with no cable holes if my devices are moved and I want it to look clean again.

Thanks for any advice to make this happen! Hope this wasn't confusing!
Steve


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## DonkeyHody (Jan 22, 2015)

I assume you're talking about a hole for wires to pass through - like in an entertainment center. I don't know why it needs a grommet at all. There's no sharp edges to cut the insulation on the wires; you just want it to look nice, right? If you're dealing with solid wood instead of ply, I'd just cut an appropriate sized hole and round over the edges. It'll be as unobtrusive as a hole in the top can be. Now as far as hiding it later, you're going to have to get more creative . . .


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## Cherryville Chuck (Sep 28, 2010)

I agree with Andy if it's a wooden top or in the back where it won't show. Just use a round over on it if thick enough or sand the edges. 

If it is a laminated top then you need it for looks but most are meant for the flange to sit on the surface. Because of that it might not look right recessed. If you do recess it I would hope to find a drill the right size or use an expansion bit to start the hole and make the recess for the lip and then switch to a bit for drilling the body.


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## OPG3 (Jan 9, 2011)

Steve, That's actually EASY to do! Most anywhere you're going to need a "grommet" - one of the sides will NOT BE SEEN. A wooden one as you have described is simple in whatever shape you desire. Just make the part(s) (one with holes & one blank) and position an oversized piece of 1/4" MDF, etc. on the back. Ideally, you will make matching backer boards, as well - with each one having matching (small) screw holes - so that the obsolete one may be removed and the blank be installed - using the same (small) screws and holes. 

This reminds me of something funny that I recently observed...I am very near completion of my new office desk for computer setup and reference table. It is 14'-3" long and 34" front-to-back. No legs, yet very sturdy - using a double cantilever design that my Dad taught me many years ago. There are electrical outlets below this desk, and I wanted the appearance and functionality to be perfect. I drilled 3- 1.25" diameter holes about 4 feet apart for grommet installation. I often utilize this size of grommets. Normally, I have several "on hand", but I had depleted my reserves - so I had them on my list for next shopping trip. 

A few days later, Joy (my wife) and I went out for dinner and were very near a Home Depot in Lawrenceville, GA. An old man walked me to electrical and then to their selection of grommets. He offered black and white, plastic and metal. I told him black, plastic, 1.25" diameter - going through 3/4" plywood. The grommets he handed me looked perfect, but they were in a plastic bag. There was something curious about them - they were ONE-PIECE! I asked if he had an open bag of those grommets? He said, "No - let's just open this bag!" He then handed me one, and as I suspected; they were ONE PIECE!

If this isn't comical to anyone reading this, picture this *potential* scenario: I have 3- 1.25" diameter holes. The grommets are ONE PIECE! I put the grommets in-place (they each have one 3/8" diameter hole molded into the top). How on earth am I supposed to get a male or female end of an electrical cord through a hole 3/8" diameter? His answer was: "No problem - just cut-off one end of the cord, slip it through the hole and REATTACH the end of the cord!" It was all I could do to contain my laughter until I was out of his line of sight.

We then went to Lowes, where their 1.25" grommets were TWO-PIECES! Now, I do not have to cut the ends off of my new computer cabling! Hallelujah! 

Otis Guillebeau from Auburn, Georgia


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## DaninVan (Jan 1, 2012)

Richelieu has what you need...

Metal Grommets - Richelieu Hardware


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## plunger (Jun 21, 2013)

Yes, this is actually a fireplace mantel that I'm painting a color-matched off-white. I have a Xbox Kinect camera up top that I want to hide the thick black cable. For now, it will be installed and is in use. But, being something that's not part of the house I'd want to be able to hide the wire access if I move, remove out the Xbox, etc.

I already installed some "orange smurf tube" conduit that reaches the media center area so I just need to get the wire into the mantel body in some neat fashion. I designed the mantel to be easily removable with two screws.

@OPG3 14' is a big desk! Yes, I've seen those grommets at both Lowe's & HomeDepot. The two piece certainly work better! My concern is the color of the plastic. It doesn't match.

@DaninVan Thanks for the link. If I can't make the grommet color match I'd probably use the metal material.


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## MEBCWD (Jan 14, 2012)

This is how I made grommets for the 3 desks I have made. if the grommet is no longer needed then a drop-in solid insert is used.


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## plunger (Jun 21, 2013)

MEBCWD said:


> This is how I made grommets for the 3 desks I have made. if the grommet is no longer needed then a drop-in solid insert is used.


Wow- those are exactly the type of grommets I would like to make. Can you explain the best way to make them to a beginner, Mike?


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## MT Stringer (Aug 15, 2012)

Measure twice...no make that thrice. I seem to always get the grommet location right in the way of the monitor! :frown:


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## DaninVan (Jan 1, 2012)

Whoa! Nice grommets, Mike!! 
(I'd be remiss if I didn't point out that they're one piece and that the OP wants two piece ones.)


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## plunger (Jun 21, 2013)

If it's a piece of plastic with the hole in the center I'll need two pieces. With a larger hole like Mike's above, that wouldn't be necessary.


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## Stick486 (Jan 4, 2013)

MEBCWD said:


> This is how I made grommets for the 3 desks I have made. if the grommet is no longer needed then a drop-in solid insert is used.


I like those... a lot...


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## MEBCWD (Jan 14, 2012)

I'll have to post a reply about how I do these later after I get back from the football game tonight.


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## MEBCWD (Jan 14, 2012)

For this example I will use a round grommet with an inside hole measurement of 1 1/2" and a flange and body thickness of 1/4".

Picture 1 shows the measurements for the grommet and hole in the desk.

Picture 2 shows the measurements for the template parts to cut the desk top opening. The template consists of a base template and an insert piece.

Picture 3 shows the base template in blue and the insert in red.

Locate the base template where you want the grommet located. Put the insert piece into the base template. Mark the inside of the insert piece with a pencil. Remove the template so you don’t damage it and remove most of the material with a drill and/or saw making sure you stay inside the pencil line. Relocate the template with insert installed and use a pattern bit to cutout the center hole as deep as possible (this hole can be drilled if it is round like in the example and you have the right size drill, use the template and pattern bit if you have another shape or odd sized hole). 

Remove the insert piece and route the ledge to hold the grommet the correct depth in the desk top (0.25" deep in the example). Remove the template

If you find that you can not remove all the material from the through hole with the template in place wait until you remove the template and use the pattern bit to finish trimming the hole using the trimmed part of the hole to guide the bit or use a bottom bearing bit from the underside to finish trimming the hole. 

Picture 4 shows the measurements for the grommet templates. The templates consist of grommet hole template, a plug template for the top of the grommet, a template for the bottom of the grommet and a standoff template that is used to steady the router base when using the plug templates.

Picture 5 shows the templates for the grommet. The grommet hole template is light blue, the top plug template is green, the bottom plug template is purple and the standoff template is yellow.

Locate the grommet hole template on the blank and mark the hole location on the blank. Remove as much material with a drill and/or saw. Relocate the template and router the hole through the blank.

Locate the bottom plug template on the bottom of the blank by inserting it in the hole. Locate the standoff template around the bottom plug template making sure there is plenty of room for the pattern bit between the templates. Route to the depth of the grommet flange around the plug template using a pattern bit.. (0.50" in the example) Remove the templates.

Use a 0.25"radius round over bit on the top side of the blank to ease the edge of the hole. Locate
the top plug template on the face side of the blank by inserting it in the hole. Mark the outside of the template on the blank and cutout the grommet outside the pencil line. Trim the edge of the flange using a pattern bit and the top plug template.

If the hole of the grommet is too small for the plug of a power cord to go through the grommets can be cut in 2 pieces with a thin kerf Japanese saw and veneer used to close the gap or notched for cord clearance.

There are other ways to make the grommets and to route the pocket in the desk top using different bits and router bushings of various sizes but you still need accurate templates to make sure everything fits properly.	

This is just the way I have made them in the past.


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