Loose mortise and tenon joints
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I’m still pretty new to the woodworking world and I need some advice. My mortise and tenon joints are loose.
I just watched Paul”s technique using a guide block and I’m going to try it out. When it comes to cutting the tenons, do I want them to end up 100% exactly the same width as my mortise chisel? I use the chisel to mark my cut lines but I come up loose. Advice?
Try cutting your tenons fat and then pare then down until they fit with the router plane.
Good advice from Paul Rowell above.
You should always cut your mortise to your desired size, then cut your tenon to the mortise, not to the size it is supposed to be.
That way, any errors you made in the mortise sizing won’t matter.
If you use the Paul Sellers method with a guide block, you will notice that Paul is paring the mortise after chopping it. This will make the mortise a little wider than the chisel (even if he is removing only a fraction of a millimeter).
So make your tenon and mortise marking a little bit wider than your chisel. How much? In function of your chopping and paring skill 😉By the way, one doesn’t always have the desired chisel width.
see this blog which shows how to make a wide mortise: https://hyvelbenk.wordpress.com/2014/03/16/hovelbenken-i-mariestad-er-pa-fotene/
It is in a Nordic language but the pictures are self explanatory.Thank you for the quick feedback guys. So if I use a marking gauge, I need to add a tad to each sideof the chisel a bit? The same if I use the router to mark my lines?
Do I start with the chisel width, add saw kerf and then add a little more?
And when I get done doing final clean up, will the tenon be the Exact width of the chisel/mortise? This is something I’m not sure about. Is it supposed to be a very tight fit?
I apologize for the beginner questions. I unfortunately do not have and craftsman in the family.
Hi,
We were all where you are once, and we are all just paying forward help we were given at the time. 😀
Set your marking gauge to the target width and mark the mortise and the tenon accordingly. Don’t add in anything for kerf or chisel etc.
When you come to cut the tenon just cut to the waste side of the line, leaving the line in place.
Kerf should not be an issue for the mortise as I can’t imagine how you would use a saw for that?
You can then test fit the tenon, trimming down with a router plane a tiny bit at a time, retesting often.
Good luck!
Darren.
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This reply was modified 2 years, 10 months ago by .
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This reply was modified 2 years, 10 months ago by .
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This reply was modified 2 years, 10 months ago by .
Thank you. With my terrible art skills I was showing the marked lines for a tenon next to chisel lol
I’ll post back my results. I’m marking my lines and will start my cuts today. I really hope I do not waste anymore wood!
Ha! You’ve clearly never seen any of my drawings… 😂
You’ll be fine, just trim the tenon down slowly, and by equal amounts on both sides, testing each time.
You should be taking off whispy amounts from each side when you get close.
Depending on what wood you are using you will also get a certain amount of wood compression each time you try to fit the tenon, so when you get your first really tight fit, take it out and put it in again, it might not be as tight the second time.
This is especially true of softwood such as pine.
If you go too far and the tenon is loose, just cut a piece of wood the same size as the tenon and glue it on to the tenon (same both sides) and then repeat the trimming process.
Cheers
Darren.
I can second the comment above about very fine paring, it feels slower, but it’s quicker than a repair or a replacement.
The guide block was developed (if I remember the blog posting / comment correctly), to help his students chop plumb, and in line. Means if you do use the guide (and make sure the chisel stays plumb as you chop), the width of the mortise will be the width of the chisel, and the position of the mortise will be governed by the guide, regardless of what you have marked on the work piece.
Its also worth noting that if you are going to use the guide, that you don’t really need to set up a mortising gauge to mark the tenon, you can use the guide for that as well (on the assumption that both pieces are the same thickness.
In the past I have been able to rescue loose tenons with long shavings. You lay them out flat, apply a film of glue to the upper surface, then wrap them around the tenon like tape. The shavings need to be thin, and you do need to be careful when you do it. Let the glue set and then trim any excess length off, and start to fit
For very loose housed tenons, split off some wood from a scrap piece and glue it to the tenon, or try a lengthwise fox tenon.
If it is a through tenon, and the stock you split has a taper, see how well it might function as a wedge (if you can get two thin wedges down either long side of the through tenon, I suspect only you would know it was there after you finish everything).Colin, Czech Rep.
It seems my comment was confusing.
If the mortise is a hair wider than the chisel,
obviously, the tenon must also be a hair thicker.Well I’ve made some a few panel rails using Paul’s mortise and tenon method using a router plane. I’m pretty happy considering how badly I have done cutting tenons with a saw.
I’m still a little worried about doing the mortises… I hope everything is a tight fit.
The more you do the better they will all become!
Just so we are all talking about the same approach, you are cutting the mortises FIRST right?
You should always cut the mortise to the size you need, then cut the tenon to fit whatever mortise you ended up with. 😀
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