Repair a bad joint

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Forum topic by SqPeg posted 04-28-2013 03:37 PM 1813 views 0 times favorited 13 replies Add to Favorites Watch
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15 posts in 2227 days

04-28-2013 03:37 PM

Topic tags/keywords: question mahogany joining traditional

While gluing up this bedside table I blew out the side of a mortise. The glue was setting up on all the other joints so I had to finish and hope I could fix the hole the next day. The piece was pretty ragged but I thought I could get back in the hole. But it would not fit. The clamping must have compressed the original hole and it just would not go in. So I tried to enlarge the space a bit. But my attempts to make the space a tiny bit bigger created an even bigger mess.

Does anyone have an idea how to fix this problem? The wood is african mahogany.

13 replies so far

View Lee Barker's profile

Lee Barker

2170 posts in 3088 days

#1 posted 04-28-2013 03:50 PM

Machines can make perfect pieces (CNC) but they can’t make handmade. Nor can they repair surprises like this.

I would chisel a flat facet on and cut a piece (from the same board if possible) and glue it on, clamping with tape. When it’s cured I’d shape it to suit and be proud of the repair.



-- " his brain, which is as dry as the remainder biscuit after a voyage, he hath strange places cramm'd with observation, the which he vents in mangled forms." --Shakespeare, "As You Like It"

View waho6o9's profile


8539 posts in 2815 days

#2 posted 04-28-2013 04:05 PM

Chisel, file, and or sand the piece to suite your needs.

When doing the dry fit, if it’s too tight a rasp or file to make a snug
fit pays for less problems. A tip I learned here on Lumber Jocks that
works well.

+1 for Lee’s advice

View MT_Stringer's profile


3183 posts in 3469 days

#3 posted 04-28-2013 04:08 PM

I have made a couple of simple repairs using either Gorilla Glue or super glue. I covered the repair area with a small piece of waxed paper and then clamped it. Couldn’t tell where the repair was when I got through.

One board had a crack on the end I hadn’t seen. I split it a little and drizzled in some gorilla glue. After it dried, I ran it through the planer with the other boards. It disappeared completely. :-)

-- Handcrafted by Mike Henderson - Channelview, Texas

View a1Jim's profile


117417 posts in 3815 days

#4 posted 04-28-2013 04:18 PM

From the photo it’s hard to tell how exposed this joint is, so it’s a little hard to give you advice how to fix it.

-- wood crafting & woodworking classes

View Gary's profile


9386 posts in 3671 days

#5 posted 04-28-2013 05:17 PM

My strange brain would route out that cut so it was square, then glue in a piece of contrasting wood to make it look like it was done on purpose

-- Gary, DeKalb Texas only 4 miles from the mill

View SqPeg's profile


15 posts in 2227 days

#6 posted 04-28-2013 05:31 PM

I have added a photo with the top in place and the bad joint at the back. The photo is taken from normal height down towards the night stand. This is how it would appear if someone came into the bedroom.

I have the piece of the shelf left over from cutting the curve in the shelf. But the visible side of the leg is the original stock width. I could probably flatten the notch I have created, cut a plug out of the shelf stock and then pair it down to fit the area. The net result, the shelf would extend a little further into the leg, but most people would not notice. But I am not certain how the finish will look on the plug versus the leg (different grain patterns) once I add oil and shellac as a finish.


View Loren's profile


10477 posts in 3886 days

#7 posted 04-28-2013 06:20 PM

Put some finish on a scrap piece of the material to check
the color, then get a burn-in stick that matches closest
(I think going a little darker on the stick than lighter
is the better approach). I use method on spanish cedar
guitar necks and you have to know where to look to
see it.

With some restraint you can cut out a piece and glue
a patch in there too. Finish filling with the burn-in stick.

It looks like you have the piece that broke out. I would
glue it back in place using fish glue, probably. If I had
cynoacrylate glue on hand I might use that but fish
glue is not as messy.

View a1Jim's profile


117417 posts in 3815 days

#8 posted 04-28-2013 06:29 PM

from the newest photo it appears the repair is not visible unless the table is turned over? If that’s the case I would take a forestner drill bit large enough to cover the damaged area and drill a hole in the center of a scrape piece of wood that’s large enough to use a clamp both ends ,then clamp the scrap over the damaged area with the hole you drilled centered over the damage ,this will act as a guide for the drill bit, then you use the forestner bit to drill deep enough to drill out the damaged wood. next take the same forestner bit to just barely drill a circle on a replacement piece of wood that’s close to the thickness of the depth of the hole you drilled in the repair area,band saw the circle out making sure you cut on the out side the line then sand to fit in the repair area. Test fit and once you have it to proper size set in place and draw a pencil mark on the plug where it overlaps the repair area and then band saw or file out the excess,if your not afraid of damaging the surrounding area this could be done after the plug is glued in place. If you glue the plug in with the hole side up(hole made by the center burr of the forestner bit) then you can just drill the plug to fit flush with you existing pieces, when gluing the plug in place take care to make sure the grain of the plug runs length wise for strength. If you want to make this look like a design element you could use a contrasting wood and do both ends of the cross member member. I hope this not to confusing.

-- wood crafting & woodworking classes

View SqPeg's profile


15 posts in 2227 days

#9 posted 04-28-2013 07:36 PM

The use of a fornester bit and plug is intriguing. At this point with the table assembled I do not have a good way to clamp down the leg, and I would have to use a handheld drill for the bit. The bit could go wild before the point hit solid wood.

I can use a hand chisel to create a square opening. The joint line will show up more easily than with the curved line using a fornester bit. With a flat plug I can do all of the work by hand. Once the plug is in place, the grain of the shelf side of the plug and the shelf will match. Same with the edge of the shelf and plug. The only thing that will not match is the part of the plug that extends into the leg. Maybe I can make a flat, slight recess in that part of the plug, then take the skin off of the damaged piece and seat it on the plug.

If that works, then the fix may be largely transparent.

I have not started finishing the piece yet so if the fix is good, the finish should add to the disguise.

I have never seen a burn-it stick before. I just watched a video by Behlen. Looks really good. I will have to check it out at some more.

View a1Jim's profile


117417 posts in 3815 days

#10 posted 04-28-2013 08:52 PM

I think Lee or Loren’s Ideas will work fine too. As far as the bit bouncing around when you drill that’s what the board with the hole in it is for to guide the bit . I would only use a hand held drill. That’s what asking questions are all about is to get Ideas you feel comfortable with. Good luck with your repairs I hope it turns out great.

-- wood crafting & woodworking classes

View SqPeg's profile


15 posts in 2227 days

#11 posted 04-28-2013 10:07 PM

Oh, sorry, I did not read your first description close enough the first time. Reading it again I can see your approach to stablize the bit. I made a full scale model of the table and will try out this approach on it to see if I can make iwork in a tight corner like this. I think Lee’s idea will be my Plan B.

View a1Jim's profile


117417 posts in 3815 days

#12 posted 04-28-2013 10:11 PM

The thicker you make the board you drill the whole in the less you have to worry about bounce around on your bit,maybe even a piece of 2×4 or 2×6.

-- wood crafting & woodworking classes

View SqPeg's profile


15 posts in 2227 days

#13 posted 05-09-2013 03:22 PM

Here is a picture of the fix. I cut a 1/2 inch square area a 1/4 inch deep to clean out all of the tear out. The cut a plug the thickness of the shelf from a scrape piece of the shelf. The shelf side came out pretty good. The edge though took on a different color to the rest of the edge when the finish was applied. I am happy with the result. The few people that have seen it have not noticed the patch is there.

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