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How do I fix this crack?

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Forum topic by JawShoeAh posted 12-09-2014 03:45 PM 1339 views 0 times favorited 24 replies Add to Favorites Watch
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JawShoeAh

28 posts in 1341 days


12-09-2014 03:45 PM

Topic tags/keywords: tip question joining

I’ve been repairing and restoring this table I bought a long time ago for my kitchen. Lot’s of basic gluing and clamping and screwing and waxing and more gluing… But this has me perplexed, I don’t know how to move forward.

The leg has a deep and long crack in it. About half way through the top and 2/3rds down. It moves barely—as in, not enough to open it up and glue it.

Cosmetically, I don’t care about seeing the crack. But functionally, I don’t want it to get worse or be a weak point.

-- .·..-._.·¨ ¤ Joshua


24 replies so far

View Dallas's profile

Dallas

3599 posts in 1954 days


#1 posted 12-09-2014 04:17 PM

With a crack like that I would take the shop vac hose and set it near the end of the crack. With the vac ‘on’, I would dribble wood glue into the crack and as it fills, just move the nozzle along the crack, following with the glue.
When the crack is filled as much as you can, apply your clamps and leave it overnight. Even if you didn’t get glue to the back side of the crack, squeezing it will force the the glue farther in.

Good luck.

-- Improvise.... Adapt...... Overcome!

View Joseph Jossem's profile

Joseph Jossem

492 posts in 1735 days


#2 posted 12-09-2014 04:31 PM

lots of super glue in crack let it soak in

View waho6o9's profile

waho6o9

7179 posts in 2043 days


#3 posted 12-09-2014 04:39 PM

Use a chisel as a wedge, tap it in the end grain to open it up

and generously add glue, remove wedge and clamp overnight.

:)

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JawShoeAh

28 posts in 1341 days


#4 posted 12-09-2014 04:43 PM

I really like the vacuum trick, I might end up going this way.

Do you think super glue would be strong enough? I saw a guy on youtube fill a crack with baking soda and CA. He first poured baking soda all over the crack, the dripped the CA on top. It looked like it just sucked it in.

-- .·..-._.·¨ ¤ Joshua

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ChrisK

1809 posts in 2548 days


#5 posted 12-09-2014 04:54 PM

CA is strong, but it is not a filler. The crack will need to be squeezed tight so the CA is only .002” to .003” thick.

The backing powder acts like a filler to keep the CA thickness low.

-- Chris K

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distrbd

2228 posts in 1913 days


#6 posted 12-09-2014 04:54 PM

Lee Valley sells a glue/powder repair kit that might just do the trick,but I have done what Dallas suggested except I blow air(gently) in the crack rather than vacuum,it works very well either way.

-- Ken from Ontario, Canada

View Joseph Jossem's profile

Joseph Jossem

492 posts in 1735 days


#7 posted 12-09-2014 05:01 PM

Ca is strong enough i have used it on over 3k refinishing jobs

View wncguy's profile

wncguy

327 posts in 1779 days


#8 posted 12-09-2014 07:10 PM

I’ve used CA glue (“Thin”) to fill in some very narrow cracks in wood I use for my boxes. I agree it’s not designed as a filler but it gets down in the crack & stabilizes it. If I need more, I keep filling it, letting it set up between applications. I have used the “Medium” for more of a filler on wider cracks at the surface.

I’ve had issues trying to spread the crack to get wood glue in & then clamp… on more than one occasion, I split the wood doing it.

Good luck, let us know what approach you use & the results.

-- Any man can be a father, but it takes someone special to be a Dad

View a1Jim's profile

a1Jim

115202 posts in 3043 days


#9 posted 12-09-2014 07:24 PM

Your crack is because you have a cross grain situation so patching or gluing it,(no matter how strong of glue) the crack is lightly to come back again sooner or later.

-- http://artisticwoodstudio.com Custom furniture

View Dallas's profile

Dallas

3599 posts in 1954 days


#10 posted 12-09-2014 07:26 PM

As has been repeated many times, modern wood glues are stronger than the wood. If you glue two pieces of wood together with wood glue then break it, you will notice that it is wood that broke, not the joint.

I like CA glue, but not for this application.
There is an old commercial made when CA glue first came out.
They glued a guys hard hat to a beam and lifted it, (with him attached), with a crane.
That is great, it shows the bonding strength and the ability to keep from being pulled apart.
What it doesn’t show is the ‘shearing’ strength of the ca glue, which from personal experience, I can say isn’t nearly what you get with wood glue.
Since wood moves with changes in humidity and temperature, and the piece you are trying to fix seems to be a good sized piece, I would consider how much or how little lateral movement this will cause.

It’s all up to you. We can give all the advice in the world, but you are the one that has to make the final decision.

-- Improvise.... Adapt...... Overcome!

View Yonak's profile

Yonak

979 posts in 987 days


#11 posted 12-09-2014 07:27 PM

After you get the gluing done, it couldn’t hurt to drill some pilot holes and put in a couple of large steel staples at the top.

View bobro's profile

bobro

308 posts in 777 days


#12 posted 12-09-2014 08:17 PM


Your crack is because you have a cross grain situation so patching or gluing it,(no matter how strong of glue) the crack is lightly to come back again sooner or later.

- a1Jim

Yes- if the pieces of wood making up the leg (looks glued up of half a dozen) were not glued but physically bound together, there would not be a crack, but a separation between the piece nearest to us in the picture, and the piece adjacent (and cross grain) to it. Since the glue is stronger than the wood, as that gap tries to form, it can’t, so it becomes a crack right next to where the gap would form.

If the movement forcing this gap is strong enough, gluing up this crack will simply move the gapping force further along, to the next nearest weakest point in the grain. Anyone who’s repaired antique or vintage furniture has probably seen such cracks, forming right alongside earlier cracks repaired by glue.

I agree with Yonak that it would be a good idea to put some kind of physical restraint on it. What you’d be doing is binding the piece nearest to us in the picture to the piece in which the crack has formed. I would bind it good and tight with a couple of countersunk bolts and nuts run through the leg and hidden under wooden plugs round or rectangular. Crank them with a socket wrench. And personally I wouldn’t use CA, but PVA, and I wouldn’t worry about getting it deep inside because the bolts would be doing the work- the glue would primarily cosmetic, to sand dust into.

If you do use covered bolts, you can make lemonade by putting corresponding contrasting plugs on all four legs as a decorative element. Cheap easy why to further hide the repair and jazz up your furniture a bit.

-- Lao Ma: You are so full of anger and hatred. Xena: Everybody's gotta be full of something.

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JawShoeAh

28 posts in 1341 days


#13 posted 12-09-2014 08:33 PM

So I decided to use a combination of suggestions.

I think given that it’s a table leg, the nature of the crack and that it’s a huge and heavy table – the concern for shear strength was big. So I decided to stick with regular wood glue. Especially if one of my larger relatives decides to take a lean on the corner of the table… lol

I used a chisel to open up the crack as much as I was comfortable doing. Then I put the shop vac on the crack, and just started pouring in the glue. Move the shop vac a little down, more glue. I did that until I got to the end.

When I got to the end, I put a smaller chisel in. I then put the hose of the shop vac over the chisel and directly on to the crack.

The shop vac really does yank that glue through the crack.

I left the shop vac on the crack for a few minutes until I was satisfied that it was filled as much as it would be filled up.

Started cleaning up the area, and preparing to turn the shop vac off and get the chisel out.

After I pulled the chisel out, it left a hole just big enough to get the tip of my glue applicator in. I shoved it in there and gave one last big squirt in.

Then it was clamp city as usual in the shop.

Thanks for all the suggestions. That went a lot better than I was thinking it would go.

I think as one last measure, I might get out the pocket hole jig and put a screw or two in the top. Or some staples like Yonak says.

-- .·..-._.·¨ ¤ Joshua

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JawShoeAh

28 posts in 1341 days


#14 posted 12-09-2014 08:38 PM

Bobro, I did think about countersinking some lags right through the leg. That’s definitely my style—form follows function… but I just couldn’t bring myself to drill into it. I really like the way this table looks just the way it is. If it fails in the future though… I have these great looking hex head lag screws waiting lol.

-- .·..-._.·¨ ¤ Joshua

View bobro's profile

bobro

308 posts in 777 days


#15 posted 12-09-2014 08:46 PM

Yeah that’s another way to hide the repair- in plain sight, like in that EA Poe story. Big good-looking bolts. Personally I’d hide the nuts and bolts under contrasting square plugs, not least because my wife likes that kind of thing.

-- Lao Ma: You are so full of anger and hatred. Xena: Everybody's gotta be full of something.

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