# How to pare tenons plumb and square



## tibi (4 Dec 2021)

Hello,

I have been working on my first workbench and I want to make it look good as I will have to look at it for many years to come.
I have planed all the wood for the base almost to the finished width and thickness. Now I plane boards to the finished thickness with my hand planes, then cut joinery (mortices and tenons), and finally glue boards together to form a component of the workbench base.

I have started with the smallest stretchers. A finished component is here:






I have found out that I have a problem to pare tenons square and plumb to the marked lines. In the pictures below, the shoulder is square and the tenon is off.








After further investigation, I think that the biggest problem is in my chisels. This problem is only exceeded by the inexperience of the chisel operator. I have been flattening this 38 mm wide chisel on the 240 grit diamond stone for 10 minutes, but it seems that it would take hours to get it flat. Other chisels are either bellied or are hollow in the middle, but have a belly just next to the edge, which makes the edge low. The tenons are 50 mm deep, and If I want to use a square block as a reference to cut plumb and square, then I would need at least 80 mm of my chisel to be perfectly flat. The chisel is at least 0,1 mm of being flat. I think I am not yet able to pare flat and square without any reference block.








Is there a better and faster way how to get the chisel flat than just using the diamond stone or should I just buy better chisels because these are way off?
Do you know some good videos on how to pare the tenons square and plumb so that I do not ruin my workbench? As you can see there would be a big unsightly gap on the shoulder if I left it as it is. I did not cut any mortices yet, so I can still remove materials from the tenons to repair them without making them too small. Also, you can see that the shoulder line (horizontal) is not uniform, but wavy. 




Thank you.


----------



## Jameshow (4 Dec 2021)

How about 50mm chisel? 

Cheers James


----------



## thetyreman (4 Dec 2021)

I would look at how you are marking out the tenon, there should a clear visible line which is your guide, for that I like using a cutting gauge, the type with an oval shaped blade which creates a very clean line and is extremely accurate, I also like to use a pairing chisel for removing the waste followed by a router plane for the very final surface to make sure it's dead parallel to the face, I don't know if any of that helps but good luck, that bench looks like it'll be very sturdy and built to last.


----------



## Jacob (4 Dec 2021)

Flat chisels not likely to make any difference. It's a popular delusion.
I'd cut the mortice first and then see how the tenon fits. Pare off wood where it's a tight fit - from the tenon, or the mortice, or the shoulders, as necessary.
No coincidence but a long paring chisel could help, say 25mm wide. The length gives you more control over the cut and being not too wide makes it easier, though not essential - any old chisels will do, not too wide.
You are working to a slightly peculiar design - are you following all the basic rues about face and edge marks, gauging from face and edge etc?


----------



## tibi (4 Dec 2021)

Jameshow said:


> How about 50mm chisel?
> 
> Cheers James


The board is 40 mm thick, so I have only 2 mm missing. But I am able to buy a 50 mm chisel, if it would make a significant difference.


----------



## Jacob (4 Dec 2021)

tibi said:


> .... But I am able to buy a 50 mm chisel, if it would make a significant difference.


No don't do it. If it's difficult go narrower not wider.
Aim at fitting tenon to mortice rather than getting one perfect then the other.


----------



## tibi (4 Dec 2021)

thetyreman said:


> I would look at how you are marking out the tenon, there should a clear visible line which is your guide, for that I like using a cutting gauge, the type with an oval shaped blade which creates a very clean line and is extremely accurate, I also like to use a pairing chisel for removing the waste followed by a router plane for the very final surface to make sure it's dead parallel to the face, I don't know if any of that helps but good luck, that bench looks like it'll be very sturdy and built to last.


Thank you. I am using the wheel marking gauge. But I have a homemade cutting gauge as well. I need to go 40 mm down on one side and 50 mm on the other and I am not sure if my Veritas router plane can go that deep. I must try it out.


----------



## Ttrees (4 Dec 2021)

I find this is an opportunity where a fancy flush cutting marking gauge can be utilized,
a beam and a slip of timber is also good for longer tenons.
A plate of aluminium I find handy as a sort of winding stick, and also for finding high spots.
I suppose one made up from preferably a slip of uber dense tropical timber might be worth trying.
I use graphite so I can make it easy to see.
Might be a bit of faff for some, but could save your bacon on the other hand.


















I can't say if you need better chisels or not, I use these cheapish flat ones for paring.
Flat backed/faced chisels being more prone to diving into the wood, so something to consider if looking to spend.
David has a good video about that.

I don't like paring assists, or at least haven't used one yet to good effect, the results I've gotten being an undercut.
Maybe I might like them if I had chisels like that, maybe someday for kumiko jigs, if I can get some cheapies.
Not that you mentioned anything about paring assists, just noting that flat chisels are more prone to undercut.


----------



## Jacob (4 Dec 2021)

tibi said:


> Thank you. I am using the wheel marking gauge. But I have a homemade cutting gauge as well. I need to go 40 mm down on one side and 50 mm on the other and I am not sure if my Veritas router plane can go that deep. I must try it out.


You don't need a router plane for the mortice or the tenon. What are you doing with it?
Mortice - chisel, ideally a mortice chisel same width as mortice (up to 5/8" ish)
Tenon - sawn from all directions, with a 'tenon' saw - another coincidence!.


----------



## tibi (4 Dec 2021)

Jacob said:


> No don't do it. If it's difficult go narrower not wider.
> Aim at fitting tenon to mortice rather than getting one perfect then the other.



Thank you, Jacob,

I have started with the smallest components (short stretchers), then I will make long stretchers and then I will make legs, where the mortices will be. I need to chop only two mortices per leg. I can make them slightly smaller and then adjust the tenons to fit in. But I need to have a perfectly square and plumb shoulder line so that it matches the leg where the mortice will be. Or I need at least to have it on the outer visible side.


----------



## tibi (4 Dec 2021)

Jacob said:


> You don't need a router plane for the mortice or the tenon. What are you doing with it?
> Mortice - chisel, ideally a mortice chisel same width as mortice (up to 5/8" ish)
> Tenon - sawn from all directions.



When I made this tenon (actually it does not look like a real tenon, it is just an L-shaped offcut) I have sawn across the grain and split with the chisel along the grain. My problem is that I am afraid to go past the line with the saw, so I saw away from the line 1 or 2 mm and then pare with the chisel to the line. When paring, always one area is lower than the rest and I need to adjust the whole surface to the lowest spot. When I do this, I inadvertantly create a new low spot and I am chasing my tail. And I do not want to make the tenon much narrower or longer during paring.


----------



## Ttrees (4 Dec 2021)

Do the mortises first, tenons can move after sawing likely a whole lot more than the other way round.
Easy to see if you ever cut a double tenon and the saw kerf closes up!


----------



## Jacob (4 Dec 2021)

tibi said:


> Thank you, Jacob,
> 
> I have started with the smallest components (short stretchers), then I will make long stretchers and then I will make legs, where the mortices will be. I need to chop only two mortices per leg. I can make them slightly smaller and then adjust the tenons to fit in. But I need to have a perfectly square and plumb shoulder line so that it matches the leg where the mortice will be. Or I need at least to have it on the outer visible side.


You need to mark both mortice and tenon with exactly the same gauges so the marks match exactly. Then cut mortice right up to the line - erring on the side of going too far (too wide is better than too narrow), then cut the tenon exactly up to the line, also erring on the side of going too far - (too narrow is better than too wide). 
Router plane is a specialised and rarely used tool which you probably don't need. I'd keep it in the box!


----------



## thetyreman (4 Dec 2021)

the router plane is ONLY for the final pass on the tenon, it creates a level of precision not usually achieved with just a chisel, it's not needed but good to use if you have one that is all, I do most of the work with a tenon saw, then pairing chisel then router plane, if you can get it straight from the saw then great but I like sneaking up on the line because I like a good fit not too tight and not too loose, the final fit is what I spend the most time on usually.


----------



## TheTiddles (5 Dec 2021)

Use a paring block.


----------



## Adam W. (5 Dec 2021)

☝︎ That's a really good idea.


----------



## hlvd (5 Dec 2021)

Use a bandsaw.
Cut the tenons roughly 1mm too thick, then cut the shoulders.
Clamp a piece of square ended timber to the bandsaw table so it’s touching the blade, just behind the teeth and square to the blade.
Now your bandsaw will take a half kerf skim cut as the blade won’t have anywhere to go sideways.
Doing tenons this way gives you vernier calliper repeatable accurate tenons.


----------



## jonn (5 Dec 2021)

tibi said:


> Hello,
> 
> I have been working on my first workbench and I want to make it look good as I will have to look at it for many years to come.
> I have planed all the wood for the base almost to the finished width and thickness. Now I plane boards to the finished thickness with my hand planes, then cut joinery (mortices and tenons), and finally glue boards together to form a component of the workbench base.


How about a Leigh FMT jig FMT Pro | Leigh FMT Pro Mortise Tenon Jig Leigh FMT Pro ? One jig that works marvels when used properly, as I can vouch for. If materials are proper square, you get hairline joints, as shown on their web pages.


----------



## thetyreman (5 Dec 2021)

hlvd said:


> Use a bandsaw.



+1 I've started doing this recently, great when you need to save some time.


----------



## Jacob (5 Dec 2021)

I've been doing 1/2" M&Ts recently with mortice machine and band saw. I bought new blade with advice from Tuffsaws which is much finer than my usual 3tpi skip tooth, cleaner cut but slower. The clean cut made a big difference.
The mortice width is fixed by the machine so the key thing is to get the tenons to fit the mortice. What seemed to work really well with this batch was to cut away half the gauge line as is orthodox but often can leave a tight fit.
So it depends on where exactly your gauge lines are. 12mm? 13mm? 1/2" etc.
A trial cut followed by a trial fit, will tell you whether to saw tight to the line or otherwise. A 3tpi cut is coarse and to allow for the roughness I'd need to saw well into the line and not just halve it.


----------



## Mark Karacsonyi (5 Dec 2021)

Hey Tibi, I see your in Slovakia, how far are you from Budapest or Balassagyarmat. Likely, I could likely help you out?


----------



## xy mosian (5 Dec 2021)

I find that using the paring chisel either across the grain, of the tenon, or more usually up the grain gives best reuslts. A definite no no is trying to pare down the grain. That way lies getting splits and having the cut run away from you. A slicing cut often works better than a push cut, and references more of the surface.
geoff


----------



## pe2dave (6 Dec 2021)

Use a hand router if you care about fit and finish. I'm happy taking off a thou shaving, makes me smile.
Just make sure your router rests firmly on the stock, or butt another piece up at the end of the tenon.


----------



## tibi (6 Dec 2021)

thetyreman said:


> the router plane is ONLY for the final pass on the tenon, it creates a level of precision not usually achieved with just a chisel, it's not needed but good to use if you have one that is all, I do most of the work with a tenon saw, then pairing chisel then router plane, if you can get it straight from the saw then great but I like sneaking up on the line because I like a good fit not too tight and not too loose, the final fit is what I spend the most time on usually.


I have tried Veritas router today, but it cannot reach 50 mm deep to clean the top side of the tenon on my stretcher. However after some trying, I have managed to get it decently square with just a chisel.


----------



## tibi (6 Dec 2021)

hlvd said:


> Use a bandsaw.
> Cut the tenons roughly 1mm too thick, then cut the shoulders.
> Clamp a piece of square ended timber to the bandsaw table so it’s touching the blade, just behind the teeth and square to the blade.
> Now your bandsaw will take a half kerf skim cut as the blade won’t have anywhere to go sideways.
> Doing tenons this way gives you vernier calliper repeatable accurate tenons.




I am sorry, but I do not have a band saw, so I need to rely on the tenon saw instead.


----------



## tibi (6 Dec 2021)

Mark Karacsonyi said:


> Hey Tibi, I see your in Slovakia, how far are you from Budapest or Balassagyarmat. Likely, I could likely help you out?


Hey Mark, 

I am like 3 - 4 hours from Budapest. I have already managed to get it done, but thank you for your kindness.


----------



## tibi (6 Dec 2021)

Also I would like to tell, that I am using blunt chisel (Bill Carter's technique) and it work really well.


https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&cad=rja&uact=8&ved=2ahUKEwjSrL-N_s70AhX5kmoFHVjEA18QwqsBegQIAxAB&url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3Dre_bp5Lp0To&usg=AOvVaw1iJqpL38evKkjE5qfqldUO


----------



## Mark Karacsonyi (6 Dec 2021)

tibi said:


> Hey Mark,
> 
> I am like 3 - 4 hours from Budapest. I have already managed to get it done, but thank you for your kindness.



If in future you need some help just shout.


----------



## TRITON (6 Dec 2021)

> But I am able to buy a 50 mm chisel,





Jacob said:


> No don't do it.


Yes do it. Not necessarily for this job, but any excuse to buy a shiny new chisel is a good excuse in my book. And who knows. 

Maybe in the future you'll find another use for it.


----------



## thetyreman (6 Dec 2021)

tibi said:


> I have tried Veritas router today, but it cannot reach 50 mm deep to clean the top side of the tenon on my stretcher. However after some trying, I have managed to get it decently square with just a chisel.
> View attachment 123528



yes I understand, that's quite an unusual tenon as well, on a normal size tenon it'd work fine.


----------



## tibi (6 Dec 2021)

thetyreman said:


> yes I understand, that's quite an unusual tenon as well, on a normal size tenon it'd work fine.


Yes, for normal tenons, I would definitely use the router. I have used it for dados in the past, so I have a little experience.


----------



## Jacob (6 Dec 2021)

tibi said:


> Yes, for normal tenons, I would definitely use the router. I have used it for dados in the past, so I have a little experience.


Forgot to say - if you are paring tenons or using a router or anything, you are remedying mistakes.
If you are doing it properly from the start there would be no mistakes, except as rare exceptions.
Some things can have 8, 16 or more M&Ts. You'd be at it for hours if every one you have to whittle with a router. It could be impossible to finish.
So you need to look at your technique. Tenons should come perfect, from the saw, every time, no chisels, no routers, just a saw.

Router planes are popular at the moment - sudden fashion in the air, but in reality nobody really needs them. 
I just sold mine for 6 times what I paid for it 15 years ago. I've never used it. I've got a woody "old woman's tooth" in reserve but I've never used that either.


----------



## Kicked Back (6 Dec 2021)

tibi said:


> I have tried Veritas router today, but it cannot reach 50 mm deep to clean the top side of the tenon on my stretcher.



Can't remember what the max depth is, but if you remove the depth stop from the shaft, you gain an extra ~10mm.


----------



## tibi (7 Dec 2021)

Kicked Back said:


> Can't remember what the max depth is, but if you remove the depth stop from the shaft, you gain an extra ~10mm.


I did it, but it was still not enough.


----------



## tibi (7 Dec 2021)

Jacob said:


> Forgot to say - if you are paring tenons or using a router or anything, you are remedying mistakes.
> If you are doing it properly from the start there would be no mistakes, except as rare exceptions.
> Some things can have 8, 16 or more M&Ts. You'd be at it for hours if every one you have to whittle with a router. It could be impossible to finish.
> So you need to look at your technique. Tenons should come perfect, from the saw, every time, no chisels, no routers, just a saw.
> ...



Jacob, 

That is right, ideally it would be the best to cut straight from the saw. But I am afraid to cut past the line, so I cut 1 - 1.5 mm away from the line. I need to correctly estimate the kerf width. But my goal is to be able cut tenons straight from the saw.


----------



## Cabinetman (7 Dec 2021)

And the other good thing about a saw finish is, that it makes for a really strong glued joint, and the rough surface allows for a tiny bit of squeeze when the joint goes together, never read anything on this, it’s just intuitive and makes sense to me. Ian


----------



## Jacob (7 Dec 2021)

tibi said:


> Jacob,
> 
> That is right, ideally it would be the best to cut straight from the saw. But I am afraid to cut past the line, so I cut 1 - 1.5 mm away from the line. I need to correctly estimate the kerf width. But my goal is to be able cut tenons straight from the saw.


I'd spend some time practicing your sawing technique. 
Essential to have a consistent marking system - ideally you use the same gauge for both mortice and tenon (if the design allows it) and leave the gauge set from start to finish of the job, incase you need to go back.
Key thing is to cut all the mortice, and the tenon _*cheeks only*_ whilst the pieces are still square and marked up everywhere and on all 4 sides. Saw to the lines. Then do all mouldings, rebates, other detail if any. Then cut the tenon _*shoulders*_ last of all.
Do a few trial runs on some scrap?


----------



## tibi (7 Dec 2021)

Jacob said:


> I'd spend some time practicing your sawing technique.
> Essential to have a consistent marking system - ideally you use the same gauge for both mortice and tenon (if the design allows it) and leave the gauge set from start to finish of the job, incase you need to go back.
> Key thing is to cut all the mortice, and the tenon _*cheeks only*_ whilst the pieces are still square and marked up everywhere and on all 4 sides. Saw to the lines. Then do all mouldings, rebates, other detail if any. Then cut the tenon _*shoulders*_ last of all.
> Do a few trial runs on some scrap?


Thank you Jacob, I will practise my sawing technique. I have a lot of scrap wood laying around. Once I am confident, I will continue cutting tenons straight of the saw.


----------



## pe2dave (7 Dec 2021)

I would rarely use a hand router for the first cut of a tenon, that's not it's job.
For straight grain, try a chisel 5mm from the finished line.
For other wood, use a saw and cut away from the line (depending on your skill).
This is when the router plane comes into its own.
Can ensure the surface of the tenon is parallel to the body of the piece.
Can adjust the thickness of the tenon in incredibly fine margins.
Can clean out the corners for a flush fit.

A tool well suited to *some* jobs, but cutting away 3" of timber? No.


----------



## Jacob (7 Dec 2021)

pe2dave said:


> .....
> Can ensure the surface of the tenon is parallel to the body of the piece.
> Can adjust the thickness of the tenon in incredibly fine margins.


No need for either if saw cut accurate to start with


> Can clean out the corners for a flush fit.


Chisel.


----------



## tibi (7 Dec 2021)

pe2dave said:


> I would rarely use a hand router for the first cut of a tenon, that's not it's job.
> For straight grain, try a chisel 5mm from the finished line.
> For other wood, use a saw and cut away from the line (depending on your skill).
> This is when the router plane comes into its own.
> ...


Sure, we were talking about the last finishing touch of the hand router, not for the whole procedure. I have used a chisel to remove the material along the grain, as the grain is straight and tenon saw across the grain. But as Jacob said, my goal is to get it right from the saw and save time.


----------



## redhunter350 (8 Dec 2021)

Tibi, it may seem a silly question but do you wear spectacles? 
The reason is I do and before having to I could “eyeball” a cut very very close to square, now with specs the only way is mark out and follow the line ! The problem is astigmatism correction factored into prescription spectacles.


----------



## tibi (8 Dec 2021)

redhunter350 said:


> Tibi, it may seem a silly question but do you wear spectacles?
> The reason is I do and before having to I could “eyeball” a cut very very close to square, now with specs the only way is mark out and follow the line ! The problem is astigmatism correction factored into prescription spectacles.


Hi, 

no I do not wear spectacles. But as I work at the computer the whole day, in a few years, I might have to.


----------



## CStanford (10 Dec 2021)

If your stock is properly four-squared then set your mortise gauge so that the tenon will fit the mortise with all six lines (there are six arrises on a regular tenon) from the gauge still barely showing on the tenon after you've sawn it out. If you've used the gauge properly, then you know the tenon is square and plumb to the rest of the board if the six lines are still barely showing. Gauge lightly! Do not dig a trench with the gauge which encourages the saw to fall into the line and obliterate it/them. Once you've lost the lines, you've lost all signposts to plumb and square as to the tenon itself to the rest of the board. Use whatever saw you like, power or hand, just make sure to leave the lines. It's not necessarily easy. A mortise and tenon joint that fits straight off the saw and mortise chisel is harder to execute than perfect dovetails.


----------



## hlvd (28 Aug 2022)

tibi said:


> Hello,
> 
> I have been working on my first workbench and I want to make it look good as I will have to look at it for many years to come.
> I have planed all the wood for the base almost to the finished width and thickness. Now I plane boards to the finished thickness with my hand planes, then cut joinery (mortices and tenons), and finally glue boards together to form a component of the workbench base.
> ...


It’s nothing to do with the chisel, it’s just inexperience.


----------



## Jacob (28 Aug 2022)

hlvd said:


> It’s nothing to do with the chisel, it’s just inexperience.


Yes and chisel flattening is just an arbitrary ritual performed by the crazy sharpening fraternity. It's a sort of voodoo and they think it wards off evil spirits..


----------



## toolsntat (28 Aug 2022)

Jacob said:


> Yes and chisel flattening is just an arbitrary ritual performed by the crazy sharpening fraternity. It's a sort of voodoo and they think it wards off evil spirits..


Intriguing, when you "pare" with a chisel is it not the object of the exercise to achieve a flat surface?
I regularly pare suitably flat hinge chops and "splice" beds with ease using a flat chisel, anything other would be pure folly would it not?
Cheers, Andy


----------



## Jacob (28 Aug 2022)

toolsntat said:


> Intriguing, when you "pare" with a chisel is it not the object of the exercise to achieve a flat surface?
> I regularly pare suitably flat hinge chops and "splice" beds with ease using a flat chisel, anything other would be pure folly would it not?
> Cheers, Andy


I can see the logic but in practice it makes little difference if your chisel is slightly "bellied" (a crazy sharpening term). You steer the chisel where you want it to go. In fact you can probably do it bevel down if you feel like it!
I reckon the normal process of honing it face down near the edge, to remove the burr, is flattening enough.


----------

