Can a check be stopped? (now with photos)

[Greg Becker]

I'm getting down to the last stages of my dining table -- the leg and apron assembly is done and getting finished and the 8/4 boards for the top were cut to length this morning (I love those Japanese saws).

When I cut one of the three boards and thought I was well past a check, the waste piece fell in two and I saw that the check continued into the remaining board. The check was due to a bark inclusion that ended a few inches before the cut. The continuation of the check that went into the board was only on the bottom half and did not continue to the top surface.

When I saw the check I filled a syringe with cyanoacrylate and filled the gap then sprayed accelerant over it. My question is, should this prevent further cracking and I can use the board as is, or, should I assume that it will continue to spread and just split the board on the table saw then edge glue it?

I hate the idea of ripping the board to eliminate the check as the table top is to be made from only three boards. The board will sit in the workshop for the next month and a half as I have a gig in Afghanistan starting Friday. I'll leave the dehumidifier on while I'm gone so the air will be stable and similar to the house where it will eventually sit. Is that enough time to see if the repair will hold or am I still taking a chance?

[Joel Moskowitz]

Yes - but not with glue.
MY dining room table which I made about 16 years ago has a check about a foot long near one edge. At the time what I did is put in two butterflies - like nakashima - but very small only about 3/4" long across the check. In 16 years it has not opened appreciably.

[george wilson]

Try putting the butterfly on the underneath side,but inlaid nearly all the way through. And it needs to REALLY FIT. If time is limited,can you put a bar clamp snugly ACROSS the table top to keep the crack from spreading till you return? No glue will stop the crack spreading. You have to use the butterfly after you get back.

[Dave Matson]

I'm not sure if this would work well in this application, but to stop a stress crack from propagating one can drill a hole in the material at the end of the crack. This redistributes the stress around the hole and prevents it from growing. It is even more effective if the hole is filled with a pin or dowel. I've only used this to effect in a plastic laundry basket :D

[Roy Lindberry]

Can a check be stopped?

Sounds like a question for your bank... :D

Unless you are talking about a Czeck, in which case I think they are unstoppable.

[Tim Null]

That would be a Czech, not Czeck.....

[James Baker SD]

Can a check be stopped?

Sounds like a question for your bank... :D

Unless you are talking about a Czeck, in which case I think they are unstoppable.


My wife is Czech and unstoppable does not begin to describe her when we are traveling and I want to rest. :)

James

[Roy Lindberry]

That would be a Czech, not Czeck.....

Ummm, yeah. That's what I get for trying to be funny...I mistype and then I can be the butt of the joke :)

[Greg Becker]

Ok, now that the jokes are out, is there any alternative to the butterfly inlay??? The end of this board will be inside the breadboard so how about a bolt and nut to squeeze the crack together?

Since this table top is not yet glued up, should I just replace the board with another? If there is a significant chance that the repair would not work 100% then perhaps a change boards would be advised. The cracked piece could then be used for some other future purpose.

[David Keller NC]

My guess is that the wood you're using is maple. Given the relatively brittle nature of maple, I would expect that crack to propagate over time and humidity changes, particularly if partially constrained by a breadboard end.

It is possible to prevent a crack from spreading with glue, but it requires that you use a non-flexible epoxy formulation with a fiber filler. The fiber filler can be just wood dust, or you can use fiberglass filler (which will be slightly stronger). CA glue just doesn't have sufficient adhesion to the surface of wood to prevent a crack like this from spreading, nor is the cured glue itself strong enough to prevent shearing apart. That's partially why CA glue directions require that you clamp the parts very tightly together, and it isn't recommended for gap-filling.

[Greg Becker]

My guess is that the wood you're using is maple. Given the relatively brittle nature of maple, I would expect that crack to propagate over time and humidity changes, particularly if partially constrained by a breadboard end.

It is possible to prevent a crack from spreading with glue, but it requires that you use a non-flexible epoxy formulation with a fiber filler. The fiber filler can be just wood dust, or you can use fiberglass filler (which will be slightly stronger). CA glue just doesn't have sufficient adhesion to the surface of wood to prevent a crack like this from spreading, nor is the cured glue itself strong enough to prevent shearing apart. That's partially why CA glue directions require that you clamp the parts very tightly together, and it isn't recommended for gap-filling.

It's 8/4 cherry.

I get on a plane tomorrow so I will let it sit for a month in my shop (kept at 45 -50% humidity) and see what happens to the crack with the CA. Then when I get back I'll see if there were any changes. if none, I may then cut the end off the board and then see if I can glue it with high strength epoxy and some kind of filler. I have about 3 inches of "spare" wood so I could cut off 90% of the existing crack.

Thanks to everyone for the help.

[Alan Schwabacher]

Look at Charles Neil's website (charlesneilwoodworking.com) in the video tips section for a video called "invisibly repair a check".

What he does is to use a bandsaw to cut the board, matching the angle of the check and following the grain. This allows the board to be glued back together without the join crossing grain lines.