Where did this crack come from?

[David Rose]

Please look at these two pics. The crack is circled in red. It is an end panel on a cherry blanket chest. The end was milled, glued and finished a couple of years ago. Then it was glued onto the body of the chest. A couple of weeks ago I attached the body to the base. Then the crack "comes out of nowhere". The blue mark on one pic shows that the rail and style also seem to have a little gap. The blue area is not noticable but the red crack is.

My concern is that after filling with shellac, whatever caused the problem might reoccur opening it back up.

The body was glued and nailed to the base. No, the nail on that edge was not near (over an inch) away from the start of the crack.

It is "ours" so we can live with it, but I would like to know what I did wrong. I've done several raised panel projects, though this is the first one of cherry, and have not had this happen in the past.

Any thoughts?

Thanks,

David

[Joe Jensen]

If you look at the grain in the cracked piece, you'll notice that the grain is very open, a sign of flat sawn wood. This is the opposite of quarter sawn. The other piece in the picture looks like quarter sawn as the grain pattern is much tighter. Even though the rail is faily narrow, it will expand and contract with changes in humidity. Generally this isn't a problem with narrow stock, but it is exacerbated with flat sawn wood. I suspect that piece was not as dry as you would want when you built the piece, and as it dried, it shrank. The glue on the end grain held, and as a result the board cracked. I'd blame it on wet wood...joe

[David Rose]

If you look at the grain in the cracked piece, you'll notice that the grain is very open, a sign of flat sawn wood. This is the opposite of quarter sawn. The other piece in the picture looks like quarter sawn as the grain pattern is much tighter. Even though the rail is faily narrow, it will expand and contract with changes in humidity. Generally this isn't a problem with narrow stock, but it is exacerbated with flat sawn wood. I suspect that piece was not as dry as you would want when you built the piece, and as it dried, it shrank. The glue on the end grain held, and as a result the board cracked. I'd blame it on wet wood...joe

Hi Joe,

Thanks for the response. The cherry was air dried for 2 years, then kept in my shop for around 2+ years with "average" humidity. I turned on the window AC about 3 months before the panel was attached. Humidity since then has been very close to 38%.

Yes, the rail is flat sawn. The top board of the base is laying flat, so also being flat sawn, would make the edge which the piece attaches to, quarter sawn. But if you look at the drawing, the bottom rail seems to have split from about the middle upward.

It seems to me that flat sawn to quarter sawn would tend to split the rail piece thickness wise rather than the way it did in height. I looked at a few other pieces I have built and found several places of flat to quarter sawn glue ups. May I was just blessed on the others. None of them show cracks, but they were not cherry either. I really don't think it's the wood, unless there was some stress in it that I have not accounted for. But...

David

[Rick Christopherson]

You presented more information here than you did at WoodCentral, but I think it tends to confirm my previous supposition that this was a micro end-check that you did not cut away. That coupled with the air-dried lumber is enough to open the micro end-check up to be visible. (See my post at WoodCentral).

This isn't an issue of whether the wood was flat sawn or quarter sawn, as it relates to the cause. Even though the flat sawn wood will contract more, it also has a greater tensile strength across the grain than quarter sawn. As I stated in my other response, this was not a high-stress fracture, so if the wood was healthy before the joint was made, it wouldn't matter which grain orientation was used, it would have survived.

[David Rose]

You presented more information here than you did at WoodCentral, but I think it tends to confirm my previous supposition that this was a micro end-check that you did not cut away. That coupled with the air-dried lumber is enough to open the micro end-check up to be visible. (See my post at WoodCentral).

This isn't an issue of whether the wood was flat sawn or quarter sawn, as it relates to the cause. Even though the flat sawn wood will contract more, it also has a greater tensile strength across the grain than quarter sawn. As I stated in my other response, this was not a high-stress fracture, so if the wood was healthy before the joint was made, it wouldn't matter which grain orientation was used, it would have survived.

Rick,

I suspect that you are right. I do remember a piece or two in which cutoffs broke along the grain. For some reason, I just didn't expect it to continue. I had exactly the right amount of wood for the project, so I used the seemingly solid piece. Another lesson learned.

Thank you,

David

[Steve Strickler]

Thinking solutions...

If you can get a clamp on it (looks like you could). Put some HotStuff in there, clamp it closed, then shoot it with some NCF Accelerator.

No shop should be without the stuff. I use it when my steam-bent chair parts delaminate a little. Great stuff.

I found it when I did a Google search. I normally get it at Woodcraft.

[Peter Mc Mahon]

What type of joint is that David? M+T , lap, bisquit? How wide is the side that we are looking at? Peter

[Jerry Olexa]

Hard to tell from the pics but I think IMHO you're dealing w wood movement issues as well as stress caused by the recent attachment to the base. Not sure, but wood is fragile and sensitive. The nailing may have contributed as well as the cut of the pieces's grain. Others might know better. I like your finish on the cherry. What is it? Sorry about your dilemma that only you will notice:)

[David Rose]

The joint is cope and stick. The rail that cracked is 2 1/2" high. The grain does not run particularly true to the cut either. :rolleyes: The finish is padded super blond shellac that is not yet rubbed out. I don't think the damage is structural in the location, though it can also be felt on the inside of the board. I'm glad this wasn't a door or something "loose".

Thanks again,

David

[Mark Pruitt]

David, since the finish is "not yet rubbed out," that is less work for you since you didn't waste time rubbing out a finish that you would wind up re-doing. That being the case, I think if it were me I would go with what Steve suggested. I haven't used HotStuff or NCF Accelerator but after reading its description I plan to familiarize myself with the stuff. It might become a very good friend to me down the road a piece.

I doubt that there was anything you could have done to prevent this from happening. I don't by any means discount the theories of how the wood was sawn in reference to the log or how it was dried, but I also have to think about the fact that this type of joint is created probably thousands of times a day in cabinet shops around the world, and how many times is the joint created with less care than you took with this one, and yet this joint went and did this number on you. Maybe it was just a piece of wood with a totally undetectable defect.:mad:

But, I bet you can repair it in such a way that even you have to strain to notice it.

Mark

[John Lucas]

All very interesting hypothesies and the answer is there somewhere. Now what to do about it? Nothing. At least, I wouldnt try to do anything. You found the "spirit" of the wood. You can try to conquer it or just make it invisible.
For the latter, get two gel stains. One to match the lightest color and one to match the darkest. Make a filler of the saw dust and the lighter stain. Place it in the crack and let dry. Next day, use 3m scratch pads (steel wool equivalent) and smooth the patch. Dont worry about color when smoothing. Just keep at it until the finish is uniform to the touch. Keep the area as small as you can. Then take artish brush and dip in the light gel stain and wipe off most of the stain on newspaper. Then dry brush the stain onto the repair area. Work the color from the center of the area to the outside edge and just let the brush wander into the other stained area...if brush is dry enough, you wont be changing the color. With the dry brush method, it may seem like it will take forever...that is good. You will find that the color does build up but not with blotches. When you have the entire repair area uniform with the base color, change to the dark gel and do the same...but more dry and try to create "grain" with the brush strokes. That small ara may take an hour of dry brushng to get it right. When it is right STOP. let dry and then coat gently with shellac spit coat.

[David Rose]

All very interesting hypothesies and the answer is there somewhere. Now what to do about it? Nothing. At least, I wouldnt try to do anything. You found the "spirit" of the wood. You can try to conquer it or just make it invisible.
For the latter, get two gel stains. One to match the lightest color and one to match the darkest. Make a filler of the saw dust and the lighter stain. Place it in the crack and let dry. Next day, use 3m scratch pads (steel wool equivalent) and smooth the patch. Dont worry about color when smoothing. Just keep at it until the finish is uniform to the touch. Keep the area as small as you can. Then take artish brush and dip in the light gel stain and wipe off most of the stain on newspaper. Then dry brush the stain onto the repair area. Work the color from the center of the area to the outside edge and just let the brush wander into the other stained area...if brush is dry enough, you wont be changing the color. With the dry brush method, it may seem like it will take forever...that is good. You will find that the color does build up but not with blotches. When you have the entire repair area uniform with the base color, change to the dark gel and do the same...but more dry and try to create "grain" with the brush strokes. That small ara may take an hour of dry brushng to get it right. When it is right STOP. let dry and then coat gently with shellac spit coat.

John,

What a great touchup tutorial! Are you suggesting applying the finish over the existing shellac, like a toner?

I haven't gotten the chest out where I can see it in its final setting. I don't yet know how visible it will be. If the crack doesn't open further, I think your idea is right on the money. Since I don't know (for sure) what caused it, the changing is what concerns me most.

It would take some "creative" clamping with the panel installed to glue it. If it will stay put, I don't think it needs that.

Thanks!

David

[Terry Hatfield]

Yo Dave,

I'd just stick a band aid over it if it were mine. :D

Seriously, bummer on the crack. Hope you can figure out something.

t

[David Rose]

Thanks t!

When we gonna go eat?

David


Yo Dave,

I'd just stick a band aid over it if it were mine. :D

Seriously, bummer on the crack. Hope you can figure out something.

t

[Terry Hatfield]

Thanks t!

When we gonna go eat?

David

Soon I hope. I am down to 130 lbs. waiting on you. :D

t

[Steve Clardy]

Soon I hope. I am down to 130 lbs. waiting on you. :D

t




:eek: :eek: :eek: You've caught up with me!

[Terry Hatfield]

:eek: :eek: :eek: You've caught up with me!


HHHHHHHHHHHAAAAAAAAAAAA!!!!!!!!!!!!!!! Actually my leg weighs more than you. :D

t

[Steve Clardy]

HHHHHHHHHHHAAAAAAAAAAAA!!!!!!!!!!!!!!! Actually my leg weighs more than you. :D

t



Lol. Well if I turn sideways I can hide.:eek: :D

[David Rose]

Even that is not necessary, Steve. :D

David


Lol. Well if I turn sideways I can hide.:eek: :D