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How to fix a loose joint?

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Forum topic by 716 posted 02-04-2016 06:51 AM 929 views 0 times favorited 24 replies Add to Favorites Watch
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716

502 posts in 384 days


02-04-2016 06:51 AM

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 ?

-- It's nice!


24 replies so far

View Mikesawdust's profile

Mikesawdust

276 posts in 2506 days


#1 posted 02-04-2016 06:57 AM

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

502 posts in 384 days


#2 posted 02-04-2016 08:25 AM

What about some epoxy?

-- It's nice!

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Mikesawdust

276 posts in 2506 days


#3 posted 02-04-2016 08:29 AM

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

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716

502 posts in 384 days


#4 posted 02-04-2016 08:58 AM

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

-- It's nice!

View rwe2156's profile

rwe2156

2200 posts in 948 days


#5 posted 02-04-2016 02:02 PM

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!

-- Everything is a prototype thats why its one of a kind!!

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jmartel

6578 posts in 1617 days


#6 posted 02-04-2016 03:21 PM

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.

-- The quality of one's woodworking is directly related to the amount of flannel worn.

View distrbd's profile

distrbd

2228 posts in 1914 days


#7 posted 02-04-2016 03:43 PM



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.

-- Ken from Ontario, Canada

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Richard H

489 posts in 1148 days


#8 posted 02-04-2016 03:48 PM

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.

View MadMark's profile

MadMark

978 posts in 920 days


#9 posted 02-04-2016 04:05 PM

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

-- Madmark - Madmark2150@yahoo.com Wiretreefarm.com

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716

502 posts in 384 days


#10 posted 02-04-2016 06:03 PM

What about this ?

-- It's nice!

View jeth's profile

jeth

249 posts in 2305 days


#11 posted 02-04-2016 06:27 PM

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

502 posts in 384 days


#12 posted 02-04-2016 07:24 PM

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.

-- It's nice!

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716

502 posts in 384 days


#13 posted 02-04-2016 07:27 PM



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

- MadMark


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.

-- It's nice!

View RobS888's profile

RobS888

1987 posts in 1312 days


#14 posted 02-04-2016 07:33 PM

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

-- I always suspected many gun nuts were afraid of something, just never thought popcorn was on the list.

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ThomasChippendale

244 posts in 399 days


#15 posted 02-04-2016 07:34 PM

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.

-- PJ

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