Disappearing Crack

[William Rogers]

This is two first for me. Sunday I was sanding the inside of a 12” diameter bowl running at 50 rpm. I heard a loud pop and knew the bowl had cracked. Darn, although I wasn’t happy with the tear out on the beading, Took it off the lathe to put in the firewood pile for later. Today I looked at it and cannot even see any evidence of a crack. It did not crack through to the inside initially, guessing the crack went about 1/4” deep. If I hadn’t known it was cracked I would have never discovered it, Will let set a week and see if it opens up again. Have anyone had this happen to you?

 

[Kevin Jenness]

Not in a bowl, but I have had cracks emerge and disappear from hollow forms more than a few times.

 

[Brent@TurnRobust]

The crack may have disappeared from the naked eye, but it didn't "heal". It's still there. As moisture in the wood changes, and the wood moves, the crack may appear and reappear, but it's always there.

 

[Sam Force]

Happened to me once, almost cried when I heard the pop!! Quit for the day and went back out the next and the crack was gone. I would not have believed it could happen but it did

 

[Darryl Fective]

I did a large, fairly thin walnut bowl with a sort of rolled rim. When I saw the cracks in it the next day, I was disappointed, but in looking at it realized (in hindsight) the rolled rim made it very rigid and limited movement. Duh, no wonder it cracked. It looked pretty bad with a large split (nearly 3/8" wide) on each side. I set it aside, but when I looked at it aa couple weeks later, the splits had closed almost completely. I opened them enough to get some glue in and lined them up and clamped lightly. You almost can't tell it was ever split.

 

[Richard Coers]

The crack does not disappear, it’s still there. the cells do not repair themselves. It is just not visible to the human eye. In a different place, your title would mean something completely different!

 

[Webb Willmott]

That’s impressive on the Houdini crack.

Should it flexed to make the crack reappear then flood it with CA glue and release the flex?

 

[Kevin Jenness]

The crack does not disappear, it’s still there. the cells do not repair themselves. It is just not visible to the human eye. In a different place, your title would mean something completely different!

If it can't be seen, it disappeared. If you want it to reappear, sozzling it with ca glue may do the trick. I'm making mostly decorative pieces; if the thing needs to hold soup it's a different story.

 

[William Rogers]

I know the crack is still there although it has “disappeared” from sight. It is 50 degrees here this morning, so I found a use for this bowl. Always liked to have a “fire” Christmas Eve and Day.

 

[robo hippy]

I have heard, but not tried, taking a cracked bowl and soaking in a 50/50 mix of wood glue and water, and the water makes the wood expand which closes the crack, and as the wood dries out again, the crack does disappear. I would figure the crack is still there. A sharp rap with a knuckle might tell you.

robo hippy

 

[Richard Coers]

If it can't be seen, it disappeared. If you want it to reappear, sozzling it with ca glue may do the trick. I'm making mostly decorative pieces; if the thing needs to hold soup it's a different story.

One definition for disappear is “ cease to exist”. previous cracks in wood never cease to exist. I was an engineer in a turbine engine group decades ago. We found cracks all the time that could not be seen, but with dye penetrant testing you could see the crack from across the room.

 

[William Rogers]

One definition for disappear is “ cease to exist”. previous cracks in wood never cease to exist. I was an engineer in a turbine engine group decades ago. We found cracks all the time that could not be seen, but with dye penetrant testing you could see the crack from across the room.

I don’t know why you are so hung up on my use of the word disappearing. Dye penetrant in metal has no value in wood working. Completely different. You just don’t seem to be able to accept disappearing, not meaning gone, but no longer visible. There are several definitions to the word disappear such as lost or can no longer be seen. I never said the crack was gone, just can no longer be seen. Let it go!

 

[hughie]

It sounds like even at 50rpm that you add heat to the bowl. A 12" bowl slightly heated will rapid change daimeter and crack, especially thin walled bowl will move around a lot. Yup, you cant see it but its there and most likely when the conditions are right it will come back. I havent tried Robo Hippys idea but it sounds logicall and it should work. In the past I have used CA siccesssfully but only dark to very dark wood and hardwood at that.

 

[Bill Boehme]

One definition for disappear is “ cease to exist”. previous cracks in wood never cease to exist. I was an engineer in a turbine engine group decades ago. We found cracks all the time that could not be seen, but with dye penetrant testing you could see the crack from across the room.

I also was an engineer in an aerospace company in my former life and we also used the dye penetrant test on critical components. When you’re flying at forty thousand feet above the ground, you can’t stop the plane so that you can get out and raise the hood to see why the hamster isn’t running.

 

[Richard Coers]

I don’t know why you are so hung up on my use of the word disappearing. Dye penetrant in metal has no value in wood working. Completely different. You just don’t seem to be able to accept disappearing, not meaning gone, but no longer visible. There are several definitions to the word disappear such as lost or can no longer be seen. I never said the crack was gone, just can no longer be seen. Let it go!

I’m an engineer, facts are important. When you suggest a crack disappeared, are you saying it will entirely safe to second turn it because the crack isn’t there? I’m going to go away as a New Year’s gift to you guys. It’s become completely obvious to me that very few of you like my style, or I guess it’s just me you don’t like in general. Happy New Year and happy turning. Look for my estate sale in a few years (if tests go well in a few weeks), there will be tons of figured maple. Literally tons.

 

[Alan Weinberg]

I’m an engineer, facts are important. When you suggest a crack disappeared, are you saying it will entirely safe to second turn it because the crack isn’t there? I’m going to go away as a New Year’s gift to you guys. It’s become completely obvious to me that very few of you like my style, or I guess it’s just me you don’t like in general. Happy New Year and happy turning. Look for my estate sale in a few years (if tests go well in a few weeks), there will be tons of figured maple. Literally tons.

So if you go away, have you disappeared or are you just not here? I don’t expect an answer since you have me on ignore, so I guess I’ve disappeared also.