Drying elm slab indoors

[Arlowtis]

I was told this is one of the best places to ask questions of this nature, so I appreciate in advance any time/advice!

 

So I recently acquired this large elm slab. It was originally 10′ x 33″ x 3.5″ but I had it cut down to 6′ for a table. Figure I’ll use the additional 4′ for a side table or maybe something else. 

 

This slab wood is from a tree that came down in a bad storm. Not exactly sure on time frame. It was cut into slabs and stickered outdoors, weighted down by two other slabs and covered by a tarp. 

 

I want to make a single slab table from this and ideally fill the cracks with epoxy. I am looking for some input on how to do this the correct way without creating more work for myself or royally messing up the wood. It’s currently at around 16.5-17% MC. The wood in my home, and specifically in the room where it will be placed, sits at an average of 7% in the current weather conditions. Not sure about spring or summer. The slab is currently stored in my garage, which is has sheet rock but is not particularly well controlled in terms of temp/conditions.

 

My goal is to sand it a bit, when I have time while it’s drying. Then when it gets to or below 10-11% I will put the legs, with slotted mounting holes, on and move it to the kitchen with a runner. Then when it drops closer to 7% I will fill cracks with epoxy and finish with something matte. 

 

Does this sound valid? Should I put mineral oil or something on it while it’s drying after sanding? Is it necessary to wait until it’s 7% (or even below) to fill with epoxy? AND will epoxy be enough to prevent further propagation of the cracks through the seasons?

 

Here’s a link to photos of the slab: https://m.imgur.com/gallery/g9vywRd
 

Edit: OH! One more – should I clean all of the splintering out of that large crack on the end?

[..Kev]

I edited your post for language, we're family friendly here..

Welcome to the forums!

You could do some mild milling on it but, I suspect it's not done moving!  Winter is usually the driest time with the lowest humidity.  I would store it in your garage on stickers and just monitor it for a month or 2.  If you need it faster, finding a home for it indoors will help that process.  I couldn't possibly predict how much faster.

[Spanky]

It takes a kiln to get wood down to 6 - 8 %    Here in the south you can air dry down to around 11 - 12% on moisture.  In the south the air has around 12% moisture. It takes 135 temp for 24 hrs to kill any bugs.

[Coop]

Hey bud, welcome to the forum! I’m no expert by any means but have read up on drying lumber, mostly from advice on here and I have dried several planks and slabs with success in the last 4 years. It’s my experience that air circulation and Mother Nature are your best friends. Sticker your pieces, whether indoors or out and if outside, provide a little cover. I paint the ends of my boards with a heavy coat of water base paint to mitigate the splitting due to drying too fast. I see no need in working/sanding until it has reached the desired humidity. 

[Martin-IT]

to kill bug: https://www.nrs.fs.fed.us/disturbance/invasive_species/firewood_treatment/, the center of the piece must get to 56c aka 133F for 30 minutes. The 24 hrs seem long.  Under 20% MC, it is very unlikely bugs will get into it...but the one in it will still do what they do. 

I stored kild dried maple in a barn that got wet...bugs got back into it.

Having the wood under higher temperature help 'set' the wood in place, it makes more stable when there is MC fluctuation.

You may have to do some negotiation, but can you set it in your home/room where it will be ?

Before you put epoxy, remove the splintering out, has some piece may raise or become loose. During drying, you can work on removing them, these were the 1st to get driest, as they are small pieces and fully exposed to the air flow.

 

 

[drzaius]

That pith in the middle of the slab may cause some grief down the road. It's the worst part of the log.

[wtnhighlander]

+1 to Dr. Zaius. No amount of epoxy will keep that slab from cracking somewhere down the road. I'd say cut the pith out, removing width about equal to the thickness, joint the edges and glue it back together. I know epoxy filled slabs are all the rage, but go find one that's been around a while, see if you still like how it looks.

[Arlowtis]

Thanks so much for the info guys! Sorry about the language in the original post - I copied and pasted this as a cross post from one I'd made in another forum and didn't even think about it. 

I appreciate all of the tips shared here. I am totally new to this and have received so much conflicting information, so hearing a pretty general consensus is refreshing!

[drzaius]

2 hours ago, wtnhighlander said:

I know epoxy filled slabs are all the rage, but go find one that's been around a while, see if you still like how it looks.

There is a Cadillac dealership here that had an enormous conference room table built out of a beautiful walnut slab. The cracks & large voids were filled with epoxy and the end results were gorgeous. I was in the a few weeks ago and had a look. The table is now a little over a year old and quite frankly, looks terrible. It's obviously been well cared for, but there's just enough light scratching & haziness to make it look like a piece of cheap plastic.

The thing is, scratches, minor dings & normal wear over time develop a patina on a surface and patina on wood is beautiful. Quite the opposite on plastic.

Epoxy is fine for filling tiny gaps & voids, but the bigger they are, the worse they'll look down the road.

I'll be so glad when the epoxy fad fades into a bad dream. End rant.

[cbin ne]

Welcome Arlowtis , the slab really looks nice.   
Plus 2 to drzaius.
It looks like you have a plan in your head and if this were any other slab in the tree you would be on the right track. Here’s what I would do at this time. I would suggest you step back to make some Design and or slab modifications.  I would not sand , oil or epoxy at this time it might cause additional issues. 
You have options.  All of which include more work, that I’m sure you weren’t planning on, but which will give you a much more viable end result.  I would let it dry and stabilize in a conditioned area first  

Here’s some ideas. Me, I’m cutting out the pith no question. 
Cut the pith out knowing you will join it together, the 2 obvious strategies live edges on outside or inside and a third idea remove the pith and creatively mimic like I saw BP Holcombe (instagram) do an a bench recently.  You might be able to rout it out, that is risky but possible. 
The elm will most likely be beautiful straight grain close to the pith  so that should be an advantage in marrying the two back together. 
Best and be well cb

[Martin-IT]

I have never used c-channel (https://legacylumber.co/collections/hardware/products/c-channel). But, I would wait until it is at a lower MC.

[Arlowtis]

4 hours ago, drzaius said:

There is a Cadillac dealership here that had an enormous conference room table built out of a beautiful walnut slab. The cracks & large voids were filled with epoxy and the end results were gorgeous. I was in the a few weeks ago and had a look. The table is now a little over a year old and quite frankly, looks terrible. It's obviously been well cared for, but there's just enough light scratching & haziness to make it look like a piece of cheap plastic.

The thing is, scratches, minor dings & normal wear over time develop a patina on a surface and patina on wood is beautiful. Quite the opposite on plastic.

Epoxy is fine for filling tiny gaps & voids, but the bigger they are, the worse they'll look down the road.

I'll be so glad when the epoxy fad fades into a bad dream. End rant.

I totally understand. 

I don't like light colored epoxy, and this is a table my wife and I are building together. She REALLY wants to epoxy the cracks and checks with a darker color. I'm pushing for a black or brown. Though I'm sure that, too, has it's fair share of looking rough after the years. 

I'm going to add some bowties to the underneath. I wouldn't mind them being visible but she isn't the biggest fan and I haven't done any so I'm totally new to it. Can't say they will be the prettiest haha.

Do you know if there's a way to remove epoxy should it end up looking worse in the years? I'm guessing no, just cut it out/re finish?

[drzaius]

I think the main thing, in my sometimes humble opinion, is to minimize the vast swaths of epoxy that are poured where there should be wood. That Cadillac table had epoxy areas the would measure in square feet.

I think about the only way to get it out is to cut/grind it out.

[wtnhighlander]

Dark color will help, as will confining epoxy to the cracks, and coating it all with a normal wood finish, like Arm-R-Seal or some such. The big concern is that the slab may continue to move, and cause more cracks. If you do NOT want to cut out the pith and existing cracks, then it needs to be as close to the normal humidity level of your house as possible.  If you have a spare room and a plug-in dehumidifier, you can speed the process a bit. Seal tge end grain with something like paint or shellac, to force the moisture to migrate out through the faces of the slab. This slows and distributes the moisture loss more evenly, minimizing checks and cracking. If you can restrict the slab from moving out of a flat plane, it will save a lot of work later. Some heavy timbers across each face, clamped with ratchet straps, will do. Some sticks of 3" wide steel channel would be better. I know this is a lot of work, but it is important. I built a large dining table from red oak slab material 2.5" thick. No live edge, just big pieces. It was air dried to 10-12% moisture content, common for my region. Four months after delivery, the owner reported that the top had cupped. When I checked, the formerly flat top had a cup just over 3/4" deep across its 40" width, even though it was bolted to a 4x4 support brace across 3/5 of that width. The moisture had dropped to 6%, even through the fully finished surface (5 coats of wipe on poly), because the owner used a large humidifier in the same space. And it was a large, open space...

Never underestimate the power of water in wood.

[Martin-IT]

I would fill the small cracks with epoxy, and clean up the major crack in the middle, and use butterfly inlay.  I looked in the past on how thick the inlay should be, but I could not find any reference. I have made some for a waterfall bench made of a cherry slab with a rotten pith. The end of the slab, was a a rotten crotch from a broken branch.  It was so rotten in the middle it broke in 2 pieces. I made the inlays the full thickness (2") and it is still holding together. 1st, stabilize its MC.

[drzaius]

I've seen tables where the large cracks are cleaned up & butterflied, like @Martin-IT describes, & then left open, with no epoxy fill. In my opinion, that looks way better.

[wtnhighlander]

9 hours ago, drzaius said:

I've seen tables where the large cracks are cleaned up & butterflied, like @Martin-IT describes, & then left open, with no epoxy fill. In my opinion, that looks way better.

+1. ^^^^

Many Nakashima table tops used butterfly keys to join a book matched pair of slabs, but with a gap left in tge middle. Looks good and alleviates certain difficulties with future wood movement.