Help with a crack...

[Steve Wurster]

I need some help on how to deal with this crack on the end of a board that has already been glued up.

I noticed the end cracks well before the glue-up, but thought they were only a little shallow and so ignored them. But earlier today I noticed that the one closest to the outside is also cracked on each side of the face. The cracks on the face go down about 5/8" from what is the top in the picture. If I put pressure on the outside of the piece I'm almost certain I can break it off by hand. The crack on the left doesn't appear to be cracked through to the face, plus I'm not worried about that one given its placement.

So what should I do here? Should I break it off and attempt to re-glue? Should I cut it off more towards the left and glue on a new piece sized to fit? I'm not worried about the grain not matching. I don't have a syringe for gluing so I think that option is out of the picture.

Any help would be appreciated. Thanks.

[jared herbert]

break it off and reglue it, then sand off the squeeze out. you shouldnt be able to see it. thats what I have done and would do again. Jared

[Troy Turner]

Can you get a wedge of some sort (chisel, shim) or something and open it up enough to work some glue in there?

If not, I'd cut it off. That way you have a clean surface to glue another piece on there. If you try and break it, you might be worse off than when you started.

[Sam Murdoch]

If this were a grain match issue I would break off the outside piece and reglue, but as you don't seem to be concerned about grain match the outside piece could be cut off with a miter saw and a new piece added pretty easily. The inside crack might just be filled with glue pressed in hard with a flexible putty knife and reclamped.

[Bill Rogers]

Could you apply glue to the top of the crack and then put a narrow nozzle attachment on a shop-vac and pull the glue/epoxy through to the bottom of the crack? A tip that I read about using this technique is to cover the nozzle tip with an old t-shirt. Once you have enough glue in the crack; clamp, wait and sand smooth.

[Chris Hedges]

Id try leaching in some super thin CA glue. Or just build it again. That appears to be a case hardening issue and could only get worse.

Chris

[Steve Wurster]

I don't want to have to build this again. The whole piece is basically a frame and panel about 18" by 38" so it's not a simple re-do. Plus I don't think I have the wood on hand.

What do you mean that it may be a case hardening issue? I don't think I'm familiar with that.


Right now I'm leaning toward breaking it off and gluing it back on. I figure if that fails I can just cut it off and glue on a new piece. For the inner crack I'll just try to press some glue in there with a knife like Sam suggested.

[jason thigpen]

i read a tip recently on getting glue into a tight crack. put glue in the crack and use shop air to blow it in. the air will force the glue down to the deepest areas of the crack. i also think breaking it off and just gluing the piece back on would work equally well.

[Kent A Bathurst]

Thin CA glue will follow that crack to wherever it goes. Multiple light applications, each followed with a light spray of activator. This will work much better than trying to force PVA glue into the crack, or removing and replacing that bit.

[Bill Huber]

I had a case some what like this a while back. What I did was to brake it off and then drilled both parts for a dowel. Glued it back together with the dowel, clamped it and have had no problem with the fix.

I am really not sure if I needed the dowel but it made me feel better.

[Chris Hedges]

What do you mean that it may be a case hardening issue? I don't think I'm familiar with that.

Case hardening is the result of improper drying techniques and can lead to a number of defects in the finished lumber. In this case, I think what you have is an example of honeycombing. Essentially, interior and exterior stresses are not equal and the wood is trying to pull itself apart. Leaching in superglue will certainly help mitigate the problem. Keep in mind, that if the wood you are using was not fully acclimated to your shop then no amount of super glue is going to fix the problem because the wood will continue to try and reach a state of equilibrium. Also note that if this is something you are sending to a client in a different climatic zone, the condition is going to worsen dramatically.

If you get chance, check out Bruce Hoadleys Understanding Wood. It is an excellent technical manual and goes a long way towards helping people really understand the material they are working with.

Chris

[Steve Wurster]

To me this seems more like checking only because I'm fairly sure I cut this piece fairly close to the end of the original board. I didn't look at that piece thoroughly enough before selecting it for its purpose and cutting it to length. I let the wood sit in another area of my basement for a couple weeks before starting to work with it. The project is a learning tower for my son so it will be going into my kitchen; not much difference in climate between that and my basement.

In the end I ended up breaking the piece off by hand and gluing it back on. I used two waxed pieces on the sides as cauls to keep it aligned. The lines on the face are visible somewhat, and the top only looks a little better. But I've already routed roundovers on the edge and side and the piece is looking quite nice. If it end up breaking in the future I'll just cut it off and simply shorten that part. That area will not get any stress thankfully.

Thanks everyone for their help.

[Jamie Buxton]

You can fill the crack with epoxy. Epoxy will wick down into the crack, and it will fill the crack to fasten the ear firmly to the body of the shelf. Use epoxy without thickening stuff in it. It is about the viscosity of pancake syrup. West and System 3 are the two big names. I get it at a local chandlery, but you can get it online at Woodcraft and places like that.

I'd put masking tape on the faces of the board where the crack might penetrate to the surface. The epoxy is thin enough that it will run through the end of the crack and out through hairline cracks on the faces of the board.

[Scott T Smith]

Case hardening is the result of improper drying techniques and can lead to a number of defects in the finished lumber. In this case, I think what you have is an example of honeycombing. Essentially, interior and exterior stresses are not equal and the wood is trying to pull itself apart. Leaching in superglue will certainly help mitigate the problem. Keep in mind, that if the wood you are using was not fully acclimated to your shop then no amount of super glue is going to fix the problem because the wood will continue to try and reach a state of equilibrium. Also note that if this is something you are sending to a client in a different climatic zone, the condition is going to worsen dramatically.

If you get chance, check out Bruce Hoadleys Understanding Wood. It is an excellent technical manual and goes a long way towards helping people really understand the material they are working with.

Chris


+1. That appears to be classic example of honeycomb.

Occasionally honeycomb will appear at the edge of a quarter or rift sawn board if it has juvenile wood running along one edge, and in these instances it is not due to improper drying. In the case of the flat sawn board shown in the photo, there is no doubt in my mind that it is honeycomb.

If you look closely at the void, see how it is oval shaped? When wood has checked it typically has a consistent gap from one end to the other. When wood is honeycombed, the gap is typically wide in the middle, and closes up to nothing near the faces of the boards. Also, normally honeycomb does not extend all the way to the surface on a rough sawn board; it only does after the board is surfaced.

[Steve Wurster]

So what kind of long-term behavior am I looking at with this honeycomb?

[Jim Matthews]

I would lay even money that you can reglue this with the wedge method mentioned above, such that it's invisible to the casual observer.

I would also hazard a guess that it will drive you bananas, knowing it's there. If you have any remaining stock with the same face grain pattern
it is possible to scarf in a replacement. If it was me (and it's not) I would cross drill a dowel from the "right" through both cracks before re-gluing.

I have salvaged several handsaw handles this way, the cross grain glue bond is very stable.

[Chuck Wintle]

I need some help on how to deal with this crack on the end of a board that has already been glued up.

I noticed the end cracks well before the glue-up, but thought they were only a little shallow and so ignored them. But earlier today I noticed that the one closest to the outside is also cracked on each side of the face. The cracks on the face go down about 5/8" from what is the top in the picture. If I put pressure on the outside of the piece I'm almost certain I can break it off by hand. The crack on the left doesn't appear to be cracked through to the face, plus I'm not worried about that one given its placement.

So what should I do here? Should I break it off and attempt to re-glue? Should I cut it off more towards the left and glue on a new piece sized to fit? I'm not worried about the grain not matching. I don't have a syringe for gluing so I think that option is out of the picture.

Any help would be appreciated. Thanks.
I would try some ordinary wood glue thinned with water and apply it to the crack and surrounding area...it should wick in without a problem to stabilize the crack.