# Tongue and Groove question



## adot45 (Feb 6, 2013)

Hello, I am putting end caps on a small bench seat to cover the end grain.
Should the grooves be in the seat and the tongue be in the caps or the other way around?
Or does it even matter?


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## Stick486 (Jan 4, 2013)

how wide are your end caps aka breadboards???
how thick???


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## Stick486 (Jan 4, 2013)

https://www.routerforums.com/router-bits-types-usage/47459-router-bits-mortise-tenon-project.html


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## adot45 (Feb 6, 2013)

I'm thinking 1 1/2 to 2 inches wide. They will be 0.868 in or 22.05 mm that's the thickness of the seat.

That other thread is way too confusing for me. I just plan on a couple of passes on the router table. The seat is only 15 1/2" wide, I can run it through the drum sander to true it up.


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## Stick486 (Jan 4, 2013)

spline it w/ a centered 5/16~3/8'' spline...
mortise the breadboard to take advantage of the grain...


.


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## adot45 (Feb 6, 2013)

I'm putting the caps (breadboards) on the end grain. I plan on using tongue and groove router bits to accomplish this.
Thanks for your help


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## Stick486 (Jan 4, 2013)

adot45 said:


> I'm putting the caps (breadboards) on the end grain. I plan on using tongue and groove router bits to accomplish this.
> Thanks for your help


okay...
be advised normal T&G isn't deep nor strong enough for the task..


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## DesertRatTom (Jul 3, 2012)

I love splines. Relatively simple. If you have a long spline, you have to use short sections with the proper grain orientation. It's also important to get both sides of the joint straight and the same size, and to put both pieces through the router with the same (usually the front) side down. If you do one up and the other down, you generally wind up having to sand, sand, sand because it's almost impossible to get a bit perfectly centered. 

If you cut the groove on both pieces face down, they will automatically line up when glued up. It will take a minimum of sanding or scraping to get a perfectly flat surface. Fingers can feel a mismatch of just a couple of thousandths 

The following is just background info. The flatter your stock, the better your joints will turn out. Which is the job of the jointer and planer. But if you flatten stock and let it sit for awhile, it may warp or twist or resume its slightly-off surface. So you want to use your prepared material fairly soon after working it. 

Sometimes you use an exotic or different color stock for the spline, which then becomes a decorative element. For example, I often use purpleheart for splines on the corners of frames or boxes because it really looks great against a lighter wood.

Splines should be very close to the exact width as the groove as possible. Too tight stresses the joint and leaves no room for glue. Too narrow and the joint will be weaker. This is where setting your saws and tools up carefully becomes important. If your table saw blade is not a perfect 90 to the table, your splines will be off as well. That's where a Wixey angle gauge come in handy. They're about $30 on Amazon.


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## DaninVan (Jan 1, 2012)

Dave; you know the old architects' adage, 'Form follows function'...couldn't be more apt than this particular application.
You're letting the availability of a specific tool dictate the design of the joint. You might regret this down the road; with the grain running lengthwise on the tongue it can potentially split off. Quite honestly, with modern glues it's not likely, but nevertheless.


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## adot45 (Feb 6, 2013)

OK, I had a plan but I am flexible. If that isn't how I should do it for the project to last, then I'm not going to do it like my original plan.
I do have a Wixey cube and I do get the tongue oriented with the long grain would be weak....SO, just to scheme this out
in my head, use a dado blade to cut mortises in the bench top ends, then cut mortises in the breadboards, then fit splines to them and glue them up?


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## Stick486 (Jan 4, 2013)

adot45 said:


> in my head, use a dado blade to cut mortises in the bench top ends, then cut mortises in the breadboards, then fit splines to them and glue them up?


yes.. or use a slot cutting router bit...


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## adot45 (Feb 6, 2013)

Stick486 said:


> yes.. or use a slot cutting router bit...


With either method the seat would be vertical huh? It's only 25 inches long so I guess that would be doable.
I think I still have a jig for my table saw that would hold it, I could clamp to. It won't happen today though because I have to think it through somemore. :| I'm using walnut so don't want any mistakes either.

Let's also keep in mind that I have to work within my skill level. Just because I work with wood
doesn't make me a woodworker.


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## Stick486 (Jan 4, 2013)

a slot cutter is done w/ the wood in horizontal...
if you were to get a slot cutting set there is so much you could do w/ them safely... dadoes, rabbets, T&G, splines, miters and etc...
the slot cutting set... Router CNC | Joinery | Stacked Slotting Set
this what a slot cutter looks like..


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## adot45 (Feb 6, 2013)

OK, I was picturing something else, like the bit for box joints. Yes, that would be the way to go. Now the plan shifts into something a lot more manageable, thanks!


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## Stick486 (Jan 4, 2013)

adot45 said:


> OK, I was picturing something else, like the bit for box joints. Yes, that would be the way to go. *Now the plan shifts into something a lot more manageable,* thanks!


good...
have you *been to this link *and studied up???


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## DesertRatTom (Jul 3, 2012)

If you buy a tongue and groove bit set, make sure they are matched in height. I'm pretty sure you can get such a set from Freud. Mine came from Sommerfeld tools. The point is that if you don't change the router height (and put a half inch grommet in the bottom of the collet), the two parts would fit right. Route face down!


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## DaninVan (Jan 1, 2012)

Walnut...there's good strength in that!


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## Cherryville Chuck (Sep 28, 2010)

Stick486 said:


> a slot cutter is done w/ the wood in horizontal...
> if you were to get a slot cutting set there is so much you could do w/ them safely... dadoes, rabbets, T&G, splines, miters and etc...
> the slot cutting set... Router CNC | Joinery | Stacked Slotting Set
> this what a slot cutter looks like..


 I agree with Stick. This is one of the bits you should buy sooner than later. The ones I've seen usually come with 4 different thickness cutters, the largest being 1/4". If you want to do T&G on 3/4" stock an extra 1/4" cutter makes it a bit easier although you can stack two together instead. My set has a set of thin shims for fine tuning the gap between two cutters and if you can find a set that has them or find a separate set of shims that would be good. The fact that you use them horizontally opens up your grooving options.


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## Stick486 (Jan 4, 2013)

DesertRatTom said:


> *If you buy a tongue and groove bit set, make sure they are matched in height. * I'm pretty sure you can get such a set from Freud. Mine came from Sommerfeld tools. The point is that if you don't change the router height (and put a half inch grommet in the bottom of the collet), the two parts would fit right. Route face down!


he already has a set...


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## DaninVan (Jan 1, 2012)

Dave; if you don't want to see the spline start and stop the grooves before the ends of the boards, ie they're not cut through to the ends.


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## adot45 (Feb 6, 2013)

DaninVan said:


> Dave; if you don't want to see the spline start and stop the grooves before the ends of the boards, ie they're not cut through to the ends.


I was thinking about that very thing Dan.
I appreciate all the thoughts from you gents.


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## DaninVan (Jan 1, 2012)

I think Stick might have posted this previously(?)...


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## Stick486 (Jan 4, 2013)

DaninVan said:


> I think Stick might have posted this previously(?)...


twernt me..


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## Garyk (Dec 29, 2011)

+1 for the splines. It would seem logical that the component with the groove (or grooves) would be the weak point and by using a spline it would add strength back to the part (s) with the groove. If both are grooved to accept the spline then the spline, along with the glue (which IMHO strengthens the joint) should give you what you want. I would forgo the dado blade and do stopped grooves on your router table to hide the ends of the spline. A small step but nicer results.

That "glue" strengthens part is another whole argument by its-self. I am of the opinion that it does (think of a LAM beam) but some have a differing opinion, as is their prerogative.


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## adot45 (Feb 6, 2013)

*Stopped Dado*



adot45 said:


> I was thinking about that very thing Dan.
> I appreciate all the thoughts from you gents.





DaninVan said:


> Dave; if you don't want to see the spline start and stop the grooves before the ends of the boards, ie they're not cut through to the ends.


Dan, the groove in each piece with a spline is what I'd like to try. After looking at some it looks like something I could do.
How would you start that groove?


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## DaninVan (Jan 1, 2012)

Dave; I (still!) don't use a router table. I like using an edge guide freehand...I can see exactly where my cut is. For me, I'd use that green masking tape wrapped over the edge at my start and stop points. Maybe 1/2" or 3/4" in (?). Then just do my cut.
I normally just hang the work piece over the edge of my bench and clamp it; do my cut.
Nothing fancy or complicated here at Fort DaninVan (except SWMBO).


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## adot45 (Feb 6, 2013)

DaninVan said:


> Dave; I (still!) don't use a router table. I like using an edge guide freehand...I can see exactly where my cut is. For me, I'd use that green masking tape wrapped over the edge at my start and stop points. Maybe 1/2" or 3/4" in (?). Then just do my cut.
> I normally just hang the work piece over the edge of my bench and clamp it; do my cut.
> Nothing fancy or complicated here at Fort DaninVan (except SWMBO).


Hey Thanks Dan, Your way works for you and no need to change it, it's the ol " If it ain't broke, don't fix it". Your way for me is a fork in the road though, at least I was thinking that I want to use my table and a slot bit, think I stand a better chance of success doing it that way, (less moving parts!). But just to understand your way, you have the board flat and you're using a slot bit right? So the router is upright. 

way.


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## Stick486 (Jan 4, 2013)

adot45 said:


> Hey Thanks Dan, Your way works for you and no need to change it, it's the ol " If it ain't broke, don't fix it".
> 
> 1... Your way for me is a fork in the road though,
> 2... at least I was thinking that I want to use my table and a slot bit, think I stand a better chance of success doing it that way, (less moving parts!).
> ...


1... take it..
2... freehand has the higher/safer success rate..
3... correct..

faster too...


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## adot45 (Feb 6, 2013)

OK I'll try it like that, looks easy as 1 2 3 eh?

One question before I go back out...what is the minimum depth of the slot that I could get away with?


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## Stick486 (Jan 4, 2013)

in this case.. more is better...
please don't think minimum...


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## adot45 (Feb 6, 2013)

Stick486 said:


> in this case.. more is better...
> please don't think minimum...


I was considering the depth of cut of the slot bits that I have. In the case of a spline here I can see the longer the better.


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## Stick486 (Jan 4, 2013)

adot45 said:


> I was considering the depth of cut of the slot bits that I have. In the case of a spline here I can see the longer the better.


what slot ''bits'' do you have??


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## adot45 (Feb 6, 2013)

It looks like the 1/4" slot cutter from my T & G set has got the deepest cut...1/2 inch

But if I knew exactly the bit for the job, I could let my fingers do the walking...


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## Stick486 (Jan 4, 2013)

get yourself a slot cutting set... or piece together as you see fit...
w/ the right bearing you can go up to 13/16'' deep..
Freud, CMT and Whiteside make the best stacked slot cutters...
also you can install smaller dia bearings for deeper cuts or still larger bearings for shallower slots... this takes additional accessory bearings sized individually or from a set...
Router CNC | Replacement Parts | Ball Bearings (open the sub links)

Router CNC | Joinery | Stacked Slotting Set
3 Wing Slot Cutter Set
CMT 823.001.11 15 Piece Slot Cutter Router Bit Set
https://www.whitesiderouterbits.com/search?q=Slotting+Cutter&type=product

.









what you can do...
.









in operation...
.


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## DaninVan (Jan 1, 2012)

I defer to Stick and the other guys that do a lot of this, Dave, my background was residential construction, not cabinetmaking. This is relatively new to me also (15 yrs).
I love this Forum...I've learned so much from the other members here. Something new every day.


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## ranman (Oct 27, 2017)

DaninVan said:


> I defer to Stick and the other guys that do a lot of this, Dave, my background was residential construction, not cabinetmaking. This is relatively new to me also (15 yrs).
> I love this Forum...I've learned so much from the other members here. Something new every day.


Same here, but monthly. :wink: Tons of good advice. I'm a total newbie to routing. I've used em, I've trued up edges, splined together flooring planks, and other flooring projects requiring a router.
I've just never been trained or told how to. I've learned by seat of the pants.
..................I'm a bit off topic. :grin:
.....carry on.


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## DaninVan (Jan 1, 2012)

"..........I'm a bit off topic."
-Randy

Welcome to the club!
-Dan


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## ranman (Oct 27, 2017)

Thanks, DaninVan.


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## DaninVan (Jan 1, 2012)

No need to be formal, Randy, Dan's good. The 'in Van(couver)' is where I used to live. Now I walk across the street to the beach and look across the straight to the city. Don't miss it.


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## adot45 (Feb 6, 2013)

ranman said:


> Same here, but monthly. :wink: Tons of good advice. I'm a total newbie to routing. I've used em, I've trued up edges, splined together flooring planks, and other flooring projects requiring a router.
> I've just never been trained or told how to. I've learned by seat of the pants.
> ..................I'm a bit off topic. :grin:
> .....carry on.


Welcome to the fray, i'd say you are right on topic.
As for router skills, you see I only know enough to get into dilemmas.
No better place to learn than here.

Was also glad to learn Dan doesn't live in a van.......


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## DaninVan (Jan 1, 2012)

"Was also glad to learn Dan doesn't live in a van......." 
-Dave

It's not over till the Fat Lady sings! 
(I'm not selling the van, just in case)


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## DaninVan (Jan 1, 2012)

adot45...................the penny just dropped. (.45)
I'm a little slow sometimes; just ask my wife.


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## Stick486 (Jan 4, 2013)

DaninVan said:


> (I'm not selling the van, just in case)


You always said it was a chick magnet...

,


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## ranman (Oct 27, 2017)

..._.....Green Acres we are here!_


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## adot45 (Feb 6, 2013)

Stick486 said:


> what slot ''bits'' do you have??


I checked out those links and decided to go with what I had. My quarter inch wide and 1/2" of depth is going to have to do the job.
I have the slots cut out in the seat and breadboards, where i have the splines sitting is the plan. I'll glue the two splines centered on the middle board.
So far so good?


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## DaninVan (Jan 1, 2012)

?...aren't you running the spline full length? That looks more like a biscuit setup.


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## adot45 (Feb 6, 2013)

Hi Dan, I'm not sure how I ended up with 1" splines but I don't have any oak or hickory wide enough for a one piece, I could glue up a spline. ?
It should go pretty much the full length of the ends?


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## Stick486 (Jan 4, 2013)

you handle it Dan...


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## adot45 (Feb 6, 2013)

DaninVan said:


> ?...aren't you running the spline full length? That looks more like a biscuit setup.


Dan, I milled some hickory blanks for the splines. The spline should go pretty much the whole length minus the ends, where it's hidden? Just use 3 big wide spline.? would this be better?


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## DaninVan (Jan 1, 2012)

Dave; we obviously dropped the ball at our end here. I/we sometimes make assumptions which are really unfair to the folks asking the questions.
So, backing up a bit, a spline is normally a _one piece length_ of either hardwood or plywood of an appropriate thickness and width for whatever you're specific application might be.
The length would be either the full length of the grooves, or stopped just short of the ends, which I think is where we went off topic a bit(?)...
In most circumstances having a second or third piece wouldn't be a game changer _as long as they butted up to one another and in no instance would you want any spline ends to coincide with the board joint! _
All your strength in that breadboard joint comes from the spline; you don't want to compromise that.
Please; if we've left anything as confusing lets discuss it further.
That old saying '_I don't even know what I don't know_' pretty much sums it up.


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## DaninVan (Jan 1, 2012)

It just occurred to me...are the longitudinal board joints also splined? As opposed to tongue and grooved or something else? Maybe a simple butt joint?


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## DaninVan (Jan 1, 2012)

I think the answer to your question about the Hickory splines not being wide enough is that's why plywood is popular for splines.
a) most of us have offcuts lying round which may be perfect for cutting into splines
b) the width of a panel is of course 4' but even the 8' length would work for splines as the grain direction isn't nearly as important as it is with hardwood splines.
- hard to imagine many projects needing more than 8' pieces.


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## adot45 (Feb 6, 2013)

I don't think we are too far off...and by we I mean me. I have the spline going the whole end now save the "blind spots"


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## DaninVan (Jan 1, 2012)

But no joins where the boards intersect, right? 
Modern wood glues are amazingly strong; others may disagree but I think you'll be fine, Dave.


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## adot45 (Feb 6, 2013)

DaninVan said:


> But no joins where the boards intersect, right?
> Modern wood glues are amazingly strong; others may disagree but I think you'll be fine, Dave.



Nope, no joins lined up, should be fine.


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## adot45 (Feb 6, 2013)

With Dans and Sticks help and a few youtube videos, here is what i ended up with for the spline. I hadn't cut any slots yet.
I'd like to get a nice rounded shape for the ends, then a decorative edge. 
Thanks


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## DaninVan (Jan 1, 2012)

!...wow; rounding the ends of the splines to match the ends of the grooves...nice touch!


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## sommtr (Jan 4, 2011)

No mention of wood movement I.e. gluing end grain to long grain. Just wondering.


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## Stick486 (Jan 4, 2013)

sommtr said:


> No mention of wood movement I.e. gluing end grain to long grain. Just wondering.


Bread boards aren't glued they're pegged/pinned to allow for movement..
see this thread.. it's discussed in detail...
https://www.routerforums.com/router-bits-types-usage/47459-router-bits-mortise-tenon-project.html


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## sommtr (Jan 4, 2011)

That’s what I thought. I got confused when a couple of folks were talking about glue making the joint stronger. Thanks


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## DaninVan (Jan 1, 2012)

It _does_ make the joint stronger; that's the problem, Tom! A nice example of the immovable object(s) meeting an irresistible force...something has to give, and it won't be the glue.
I'm not suggesting using it, but from a mechanical perspective, something like 'subfloor adhesive' (PL400, Liquid Nails, etc.) would offer some elasticity.
The trouble with those rubbery adhesives is that they don't work as thin layered glue. They need a bit of body in order to stretch. _And they're really messy._


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## sommtr (Jan 4, 2011)

I hear you. Years ago I built a coffee table with breadboards. I used a glued tongue and groove joint for the connection. After about 3-4yrs a crack developed in the middle of the table running the length of one board. But the good news is that after 10+ yrs, those breadboard joints are holding up just fine.


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