# How to fix a loose joint?



## 716 (Nov 22, 2015)

Let's say you messed up a mortise/tenon joint so it is too loose. Would you:
1. Throw out the offending piece and make a new one.
2. Use some kind of thick glue to make it work ?


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## Mikesawdust (Jan 29, 2010)

If it's not a through tenon, glue a thin piece to the side of the tenon. If need be glue thicker pieces to both sides of the tenon, then shave it off slowly with a hand plane, I use a shoulder plane for this, till you achieve a tight fir


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## 716 (Nov 22, 2015)

What about some epoxy?


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## Mikesawdust (Jan 29, 2010)

you can definitely just epoxy the joint, two part epoxy would be best in that case; less shrinkage


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## 716 (Nov 22, 2015)

Ok, thanks, time to go to HD to get some epoxy.


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## rwe2156 (May 7, 2014)

Good ww'ing is a No Gap Zone!!
Go get the epoxy you'll need it anyway but…

Mike got is right in his first post. Do it that way if you want to do it right!


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## jmartel (Jul 6, 2012)

Thicker glue and epoxy really isn't the answer. The best solution is to glue some thin wood or veneer to the cheeks to make it thicker and re-cut the joint.


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## distrbd (Sep 14, 2011)

> If it s not a through tenon, glue a thin piece to the side of the tenon. If need be glue thicker pieces to both sides of the tenon, then shave it off slowly with a hand plane, I use a shoulder plane for this, till you achieve a tight fir
> 
> - Mikesawdust


That in my humble opinion is the right way of fixing the problem, thick epoxy will work for a while but it'll fail eventually.


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## RichardHillius (Oct 19, 2013)

The best answer is to glue a filler piece on to close the gap but a couple draw bore pegs would go a long way as well assuming you have a good shoulder mate.


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## MadMark (Jun 3, 2014)

Use a piece of brown paper bag to wrap the tenon at gluing time. This will tighten up the joint. Bulk glue has no strength to hold a loose joint.
Build it tight, build it right.

M


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## 716 (Nov 22, 2015)

What about this ?


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## jeth (Aug 18, 2010)

Hello 716, if the idea you show in the image is a wedge, unfortunately it's not such a good idea.. A wedge should always be oriented across the grain, especially when the piece you are joining into is narrow, and the joint is near to the end of the piece, as shown in your example.
If you think about it, as the wedge in your example is driven in it puts pressure on the two halves of the tenon either side of it, which in turn are going to put pressure on the side walls of the mortise and you are possibly going to get a split that runs up from one of the top corners of the mortise to the end of the mortised piece. 
Ok, it might work if you don't drive the wedge in too hard or far, just enough to fill out the mortise, but it's risky and not "proper practice". 
The proper orientation would be across the width of the tenon, so pressure is against the end grain ends of the mortise, avoiding the risk of splitting along the grain, but that's not going to widen your tenon to fill the gappy joint.

As you seem to be dealing with a through tenon, if you follow advice above of gluing on some shims and refitting the tenon - if you pare or plane the cheeks well you should get a clean joint and it may not be noticeable. 
Another option if you want to be sure of no visible joint lines on the end of the tenon would be to cut the tenon off, mortise the end of the "tenon" piece and glue in a floating tenon. If you mortise to the exact same width as your existing mortise then if your tenon piece fits one mortise it should fit the other and a floating tenon is very easy to adjust with whatever means you have available. I would use a block plane to creep up on a fit, but if you don't have one then you can use a file or sandpaper on a flat surface.


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## 716 (Nov 22, 2015)

Makes sense although we are not talking about a true wedge glueless joint, just a way to make the gap between the tenon and mortise more optimal.


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## 716 (Nov 22, 2015)

> Use a piece of brown paper bag to wrap the tenon at gluing time. This will tighten up the joint. Bulk glue has no strength to hold a loose joint.
> Build it tight, build it right.
> 
> M
> ...


Is it really going to work ? Naively I would think this is the worst imaginable scenario, suitable only to fix a loose joint on a chair before putting it on craigslit.


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## RobS888 (May 7, 2013)

Turners do that to hold a bowl, so it should be fine, DKV, I mean 716.


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## ThomasChippendale (Nov 6, 2015)

With the wedge, it will only make the end gap look right, Inside the mortiee, the tenon will still be loose and the whole assembly fragile. I also advise with glueing an extra piece and shaving it down to have a precise fit. If Paper or thick glue would provide for a strong joint, I would not have spent so much on measuring, sharpening and tooling. If you use the tenon cheek leftover piece, the grains should match perfectly, assuming they were cut away and not milled down.


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## MadMark (Jun 3, 2014)

The brown paper will be under a compression load and will bond tightly.

Try it before dismissing it 716

M


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## JBrow (Nov 18, 2015)

716,

Although not something I incorporate into my designs, you could celebrate the mistake with contrasting wood on a through mortise. For example, if the tenon is walnut, use maple or vice versa.

Glue the contrasting wood to each side of the tenon, then re-cut the cheeks of the tenon to fit just right. To get a good looking through joint, cutting a little more off the tenon cheeks before applying the contrasting wood might be required. However, the more you cut off the tenon cheeks, the weaker the joint may become. Ensure the grain direction of the contracting wood run in the same direction as the tenon grain.

As has already been said, adding to the tenon is the best method, in my view, to correct an undersized tenon.

Regarding the paper bag idea, if the bag has no coating (like wax), you are working with a dark wood on a through mortise, and the slop in the joint can be removed by the paper, then, since paper is made from wood, it should work fine.


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## 716 (Nov 22, 2015)

The wet paper has 50% or more chances to tear up when being squeezed into a gap by hammering onto the rail with a mallet. It is also technically just a woodfiller in this application. I really see not advantage in it over epoxy



> If it s not a through tenon, glue a thin piece to the side of the tenon. If need be glue thicker pieces to both sides of the tenon, then shave it off slowly with a hand plane, I use a shoulder plane for this, till you achieve a tight fir
> 
> - Mikesawdust
> 
> ...


Can you elaborate a bit more in this ? Why should epoxy fail ? A quick search on the internet shows that experiments prove it to have stronger bond with wood than Titabond. It is not used widely because it is to pain to work is and is more expensive not because it fails.
I admit though there is something I do not know here.


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## pintodeluxe (Sep 12, 2010)

Unless it is a large or special piece of lumber, I usually just toss it in the scrap bin and make a new one. The rejected piece can become another useful part some day.


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## distrbd (Sep 14, 2011)

> Why should epoxy fail ? A quick search on the internet shows that experiments prove it to have stronger bond with wood than Titabond. It is not used widely because it is to pain to work is and is more expensive not because it fails.
> I admit though there is something I do not know
> 
> - 716


If the joint is under any amount of stress like a in a chair,table, the constant pressure /movement on the joint combined with expansion /contraction of two different material within the joint(wood and epoxy)will eventually cause failure.
BTW,Pinto has the best solution.(post #19)


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## MadMark (Jun 3, 2014)

Bulk glue has no strength by itself. PVA glues will bond brown paper well. The key is to fill the gap with something other than glue. Cutting a vanishing sliver will work, but the paper actually has a more constant thickness. At .003-.005 per ply brown paper will fill. If your gap is larger, remake the piece.

Understand that a rock of epoxy will act as a pivot failure point. The pva in a wrapped tenon will hold as well as in a better fitting tenon. The pva is absorbed into the wood and paper fibers and locks the joint tight.

M


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## ThomasChippendale (Nov 6, 2015)

When we use paper to glue blanks to turn bowls on the lathe, the main advantage is that is separates easily, the glue hardly penetrates a few mils, the paper will split through the center leaving paper on both the bowl bottom and faceplate. Nothing beats a well made tenon mortise joint and laminating a wood layer on a tenon takes less time than me answering this thread. Penetration and epoxy saturation is wishful thinking, when you scrape or sand finishes, you realize they have not penetrated the wood surface much, same will happen with brown paper or wood inside the mortise.


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## dalepage (Feb 6, 2016)

I use scraps of veneer to fill the gaps.


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## ThomasChippendale (Nov 6, 2015)

Now you see it:










Now you dont:


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