# Live edge wood slab cracking question



## CanOfWorms (Sep 19, 2016)

Hi,
I bought on ebay a live edge wood slab for a desk, that was sold as a red cedar, kiln dried. I took it to a shop last week to plan it, as while drying, it curved the sides up by about 2mm and I could not sand it flat enough at home. (At the wood shop I was told it is an aromatic cedar rather than a red cedar) It got really beautiful and flat and I started filling up the cracks with epoxy. However, now each day I am seeing new and new cracks surfacing. Small ones, but each day 2-3 more.
I assume it is due to the planer, which I was told pressed down hard on the wood. The seller is not responsive on ebay, so I have no idea how long it has been drying, but this is for my wife, so I have a lot of pressure building up to get it done now.
Do I assume right that it may not have been drying long enough and I should wait a little longer?
Or is it "normal" for some time for the wood to adjust after such a treatment and say in a week or two it should stop developing new cracks at this pace (I understand that it will still "breath" later, but I hope over much longer period of time) and I could go ahead filling up and staining it then?
Any advice is greatly appreciated!


----------



## Steve Neul (Sep 2, 2011)

The color of the slab and the smell when you bought it would be a good indication of how fresh the slab was. If the colors and smell were pretty vibrant I would assume it was freshly cut. If the color was pretty bland and no smell it may be a year old. Assuming the wood was recently cut you really should wait a year for every inch the slab is thick before using it. The wood needs to season and be stored someplace air can get to both sides. The recent splitting suggests the slab may be fresh. 

The crack before it gets any bigger you might put a bowtie patch on it.


----------



## CanOfWorms (Sep 19, 2016)

Dear Steve,
Thank you very much for your help!
The smell was intense both when it arrived and unwrapped from the plastic and after it was planed. The color was pretty faded, more vibrant after sanding.

But the cracks are really small, haircracks only, nothing that would need a bow tie. Could you please tell me what happens if the wood is not really dry and I was to finish it (fill cracks w epoxy and I am planning on coating it with Osmo 4-5 times)? I assume I will lock in the humidity indside, cannot breathe and it will eventually crack, bend and/or warp? I am contemplating going ahead anyways hoping for the best, but would like to know the worst possible outcome too.
Thanks again!


----------



## Steve Neul (Sep 2, 2011)

It's just unpredictable what would happen if you would complete a project with green wood. Cedar is better than most but the wood could warp or the cracks could open up really wide. It could also not do anything more than what it would do if you waited until it dried. It would just be a gamble. 

The cracks if you could drive a wedge in the end of them to where the crack would open up you could work some glue into the crack and put a clamp on it. What you would do is put a bead of glue over the crack and rub it into the crack with your thumb. With enough persistence you can keep rubbing glue into a crack until it comes out the bottom side. Just be sure when you are done you wash the glue off the surface with a wet rag.


----------



## CanOfWorms (Sep 19, 2016)

Great, very-very helpful!
Thank you!


----------



## firehawkmph (Apr 26, 2008)

Do you have access to a moisture meter to check moisture content?
Mike Hawkins :smile3:


----------



## Tennessee Tim (Dec 15, 2010)

From all your info (photos are very helpful please) this WAS NOT a KD'd piece of wood, a correctly AD'd piece wouldn't do these things either. You can't always go by color or fragrance IF you don't know what it looks or smells as freshly cut. I have ERC in storage that hasn't seen much daylight since been dried...to a newbie it's radiant in color and the smell it's strong if your not accustom to freshly cut....but for Steve or I it's dull(er).

You shouldn't have any drying process for the wood if it was KD'd. The cupping and checking/cracking is a tell/tell sign of high MC. Planers shouldn't have a squeeze or pressure issue on the wood.

It's best to let it completely dry or by another from a reputable seller if needed quicker. Your definitely not the first person to make the mistake on high MC whether buying a piece of wood or building with incorrect MC level. There's alot of sawyers whom have NO idea what is correct MC for interior use, they just saw.

Your e-bay seller isn't responding for a reason....IT'S WET!!! ......not dry.


----------



## CanOfWorms (Sep 19, 2016)

Thanks very much for the responses, please see a few pics of the piece. They look a little more saturated on the pics on my computer screen, than in real life. The last pic shows the small cracks that popped up after the planing and they seem to have stopped to pop up any more.
I will try to find a moisture meter in the coming days, I didn't think of that. Thanks again!


----------



## Steve Neul (Sep 2, 2011)

What I was trying to say about the smell and color is this board. It was kiln dried but was surfaced about a year ago. Before I sanded the end of the board it didn't have very much smell at all. The color of the board since it was surfaced has changed to more of the color of western cedar than eastern cedar.


----------



## Al_Amantea (Dec 30, 2014)

You can pick up a cheap moisture meter at lowe's or home depot from General tools for around 25 to 50 dollars that would work fine for your use here, and also in the future.

If this was kiln dried, the moisture content would be less than 12% (most likely around 7 to 8%). if air dried, less than 16 to 17% (average around 12 to 15%). 

Any more than that, and there is no possible way this is dry enough to do anything with at all. Wood has to be less than 15% moisture in order to prevent mold or mildew growth, and I personally don't work with anything over 12% for outdoor projects, or 10% for indoor work.

If you attempt to finish or seal this slab higher than 12%, you will most likely see your finish lift and peel within 6 months. over 15%, and you are really tempting fate.


----------



## jeremymcon (Oct 16, 2014)

Is it only cracking around the one knot? Wood grain can get funky around knots sometimes - it could be that planing just released some stresses in the wood. Generally when I think of cracks forming in wood that is drying, I think of thin cracks forming at the sawn ends of the board. Called "checking" I think. 

If you're not seeing any checking, you may be ok to go ahead with your project, especially if you think the cracking around the knot appears to have stopped. 

I'm pretty new to woodworking though, so others may have a different opinion.


----------



## Tennessee Tim (Dec 15, 2010)

Ooooops the pics show it has probably been dried. I assumed "cracks and cracking" were like from the end as checking, splitting and such. With ERC drying is also tricky, overdrying is a issue which from my understanding it gets this type of cracking. One of the top drying guys told me it's best to stop at 10% MC during drying and not 6% as with most hardwood due to the brittleness of ERC creating extra cracks.
After posting the other night I realized there's a possibility (a very common shop mistake) that when you laid your boards down one side was flat on a surface and the MC of shop and wood being differ might have caused the cupping. This can happen overnight, If the sides bows up your shop is dryer, IF the center bows up your shop is wetter/higher MC.

Attention all woodworkers!!!! When laying larger/wider boards/glued up tops for a project ALWAYS lay them on large stickers so the wood and shop can acclimate (average out MC's together). This prevents the most common question we get here about cupping that isn't related to incorrect MC/drying in the wood , it's the imbalance of the 2 parties (wood vs shop MC).

MOST of our shops aren't MC controlled....I keep a dehumidifer in my storage more than my limited shop area. Most of our shops are a corner or portion of a larger area (garage, basement, barn, shed etc., etc.) and that makes it even tougher as controlling.

Check the MC of the wood, I believe from photos you my be dry, only testing will tell.


----------



## CanOfWorms (Sep 19, 2016)

I got a moisture meter and it was pretty consistently reading between 8-10%, but mostly 9%.

This piece was cupping to begin with, hence the planing. The guys were great there and as far as I could tell not only knowledgeable but in love with woodworking. Before doing the job, they said; it may not get it perfectly flat, bc the planer will put some pressure on it and that may flatten it under the plane and bend back as it's out again. We did 3 runs and by the last one, it was pretty darn flat. When I got home, I started to fill all the cracks w epoxy and the next day there were new tiny crack again. I filled them and the cycle repeated 2 more times, so that was when I turned to you guys. Now I am not seeing any new cracks, so I will finish epoxying and then I will finish it too.

Thank you guys again for all the ideas and knowledge, very much appreciated!


----------



## Al_Amantea (Dec 30, 2014)

Well, at 8 to 10%, it has been kiln dried for sure. It must be a moisture imbalance from your shop to the wood. 

Most ti es, planing will not correct a warrant like this. The slab should be jointed flat on one side, then have the other planed to make it parallel to the jointed face. Even this isn't a guarantee of remaining flat. After joining and planing, sticker the piece so that air can move around all sides, and let it rest in your shop for about a week. Then begin your project and you will have the best chance of it remaining flat.


----------

