# How much dado is too much?



## CB_Cohick (Dec 22, 2014)

I am building a version of Norm's router table from the Creston WW plans. For the drawers, the plans call for 1/2" x 3/8" dadoes in 1/2" stock. That seems a bit much to me. I may end up decreasing that depth some partially dependent on the LJ wisdom I may receive  My gut feeling is that half of whatever stock I am using is about as far as I should go, but I am a novice. What say you, Lumberjocks?

Thanks in advance for your input.


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## waho6o9 (May 6, 2011)

Wise move


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## SirIrb (Jan 12, 2015)

1/3 to 1/2 deep on dado. I think his plans call out for too much. I never thought he was St. Norm. I cant put my finger on it. Maybe its just the praise and adoration he gets from so many. Any way, good thought in cutting the dado down.


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## CB_Cohick (Dec 22, 2014)

> I never thought he was St. Norm. I cant put my finger on it. Maybe its just the praise and adoration he gets from so many.
> 
> - SirIrb


St. Norm, now that's funny :-D I love watching New Yankee Workshop. Norm builds some nice furniture, and has been a pioneer in developing woodworking programming. But, as you suggest, his way is not the only way.


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## CB_Cohick (Dec 22, 2014)

I think I just figured out the discrepancy. The plans suggest in the materials list that drawers are constructed from 1/2" ply. However, adding up the width of the drawer pieces + the drawer slides makes it clear the intent is to use 3/4" ply. Problem solved.

However, I am still curious what everyone's thoughts are on a guideline for dado depths. So far we have one vote for 1/3 to 1/2 of the overall thickness.


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## a1Jim (Aug 9, 2008)

As a general rule of thumb I stick with half the thickness of the material I'm dadoing,I believe that even 1/4" deep dados are plenty strong,basically you just need enough of a dado to have sufficient material to have good shearing strength.
I can't believe I'm conterdicking good old Norm


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## CB_Cohick (Dec 22, 2014)

> I can t believe I m conterdicking good old Norm
> 
> - a1Jim


I think you are ok with Norm. I misled you by misinterpreting the plans


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## a1Jim (Aug 9, 2008)

Whewwwwwww! 
Thanks, Norm was a major influence in my woodworking adventures


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## HornedWoodwork (Jan 28, 2015)

I vote 1/2 or less depending on the stock. Up to 3/4 I'd opt for 1/2. Over 3/4 I'd step down to 1/3 or so, and probably not go any thicker than 1/2" ever.


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## Gene01 (Jan 5, 2009)

For 3/4" drawers, 1/4" should be good. But, no more than 3/8.


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## NoThanks (Mar 19, 2014)

I've always used 1/4" deep for 3/4 stock on cabinetry. 
Anything else I just use my best judgement.
All materials require different methods. 
I might do different depths in plywood compared to hardwood or particle board. 
For me there is no rule of thumb.


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## a1Jim (Aug 9, 2008)

Wikipedia

"A rule of thumb is a principle with *broad* application that is not intended to be strictly accurate or reliable for every situation. It is an easily learned and easily applied procedure for *approximately* calculating or recalling some value, or for making some determination" )


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## Ghidrah (Jan 20, 2015)

Sometimes people need a perspective slap.

Just to point out the obvious, there were many people involved in the making of and processes of TNYW and all woodworking shows. The main process is providing entertainment.

2nd is safety, the insurance companies involved can't afford lawsuits so they go out of their way to provide a show that shows the safest method and won't implicate itself. That way if someone gets hurt emulating the project, the show can provide proof they weren't the cause, never alluding to any unsafe methods. One would be amazed at how many try to make a living out of law suits, (and I don't mean lawyers).

3rd, consider the projects Mr. Abrams completed; anyone in the woodworking trade, (framing, carpentry, furniture making) for any length of time has the tools and knowledge to construct everything he did and in some cases better and faster. Everyone else without the tools and knowledge, in most cases didn't understand most of what he said or did with any clarity. The proof is when one hears a customer say, "Well, that's not the way Norm does or did it"! Dimes to dollars tons of us have heard that one maybe more than once.

4th, "How can it be that expensive, Norm does it in a half hour TV show"! Many viewers temporarily, (I hope) lose the ability to conceptualize time and cause and effect. The project on the TV show wasn't completed in a half hour but in many cases days worth of labor by multiple people let alone the production crew set ups between takes. Often I'd notice day and night conditions in the same episode through a window as Norm passed by.

"Norm never makes mistakes". If you watch the old shows you see Norm begin the episode, watch his hands, in some episodes less than halfway through the episode Norm has one or more wounds on his hands and or Band-Aids. I always wished they'd show a mistake or outtakes of failures. I really appreciated Tim Yoder and his wood turning series, he wasn't afraid to show errors or talk about them during the show.

Lastly like Norm, most or all the tools seen on all the woodworking shows are donated by the manufacturing companies as advertising. Any tool not donated/gifted to the show has its name and or logo blacked out. The only way to know the manufacture is to be aware of the tool colors and body styles same goes for the lumber, if the show pays for it, the retailer is not mentioned.


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## JoeinGa (Nov 26, 2012)

Usually I start at 1/4" and may go upwards of 1/2 the thickness, depending on how much weight I think it may need to hold. 
.
.

Is "conterdicking " even a word?


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## Ocelot (Mar 6, 2011)

Since I'm a perpetual novice, in a bookshelf, I have used 1/8" dados with screws - yes - into the end grain (long screws).

We shoiuld do a test - make a little stool like that and see if a 200lb man can stand on it. I suspect it would hold just fine. Wood is very strong in compression along the end grain.

I remember looking up some guidelines for framing construciton. An 8ft tall triple 2×6 column (3 pine 2×6's nailed together) is rated to safely carry something like 26,000lb! That's over 1000lb per square inch of cross section. So, a 1/8" deep dado, on a 4" wide board should be able to carry a static load of 500lb (as long as there is something holding the shelf firmly in the dado, so it doesn't slip out).

But, I suppose we also have to consider that the end of the board inserted into the dado is subject to crushing in the direction of the flat grain. Hmmm … possibly that's the limiting factor.

-Paul

P.S. Hey! I have a cat just like that too!


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## a1Jim (Aug 9, 2008)

Hey Joe

"Is "conterdicking " even a word? " I checked no it's not a word. Just consider the source 
Have good one buddy.


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## NoThanks (Mar 19, 2014)

> Wikipedia
> 
> "A rule of thumb is a principle with *broad* application that is not intended to be strictly accurate or reliable for every situation. It is an easily learned and easily applied procedure for *approximately* calculating or recalling some value, or for making some determination" )
> 
> - a1Jim


Thanks Jim,
Not sure if you were pointing this out to me or not. What I'm saying is that when I approach a project and go to determine the depth of a dado, I don't start out with, Example: OK 2 thirds would be this deep, or 1/2 would be this much. I look at the project and determine from experience what I think the depth should be.
In other words, I don't USE the "rule of thumb" theory.
Appreciate the schooling though. 

Edit: Sorry, I wasn't singling you out because you had mentioned rule of thumb in your post.


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## a1Jim (Aug 9, 2008)

Iwud4u

I was responding to your post but my Wikipedia quote was just meant as a clarification of what I thought rule of thumb meant. I did not mean to criticize you,nor did I think you were criticizing me. I need to check these things out to see If I have it right or not,remember me I'm the guy who posted conterdicking instead of contradicting. )


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## AlaskaGuy (Jan 29, 2012)

95% of all my dadoes are 1/8 deep. Just enough to register the parts. Rabbets, like letting a back into a cabinet will be deep enough for the back to be flush with the cabinet.

Many of my cabinets are butt joints with out dadoes.


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## JoeinGa (Nov 26, 2012)

I dont generally NEED to use "Rule of thumb". 
Since I'm a man, I can measure Anything by sight! 
.
.
.
My wife has known for years that *THIS *is 8" .
.


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## daddywoofdawg (Feb 1, 2014)

I'm sure the people that draw/type up the plans wouldn't know which end of a hammer to hold,norm sells or presents the plans to a publisher and he's done with it.then the publisher (see some low paid worker)Takes those plans types out the how-to and draws plans that look like norm's and sells them.
What used to bug me about that show is he used to push vermont american tools,and they were some real junk!


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## a1Jim (Aug 9, 2008)

Daddy
your sure right about some of the folks who draw up plans not knowing what they were doing.
The thing about Vermont American router bits is correct they are junk,but I don't think Norm pushed any products, in fact most of the brand names of tools were covered but tape.I'm sure all TV shows have sponsors products that they use even though they don't like them,but sponsors pay the bills, so if your producer says here's the router bits your going to use,then you use them.

Let's blame Russell Morash )


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## MrRon (Jul 9, 2009)

If you were cutting a dado in MDF, I would go only 1/4 the depth; 1/2 the depth for anything else. For a rabbet for a cabinet back, I would use 2/3 depth to allow enough edge distance for nails or staples.


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