# Beginner Question: Filling cracks on large Elm round



## Road Explorer (Feb 24, 2011)

I'm relatively new to woodworking and will be making an outdoor sign from a large elm slab. The slab is roughly 3' x 4' x 3" thick and is fairly dry.

My question is, how do I best fill the cracks and ensure they or the filler don't separate during the changing weather throughout the year in the Seattle area? Should I consider incorporating a bowtie insert of some sort to prevent separation?

Also, I don't mind leaving the cracks in as they'll add character, but I want to make sure that their existence won't doom the piece out of the gate either. Therefore, what would the best finish be for this assuming there will be painted elements underneath?

Attached is a picture of the cracks, which emanate from the center of the slab.

I'm new and have taken on a pretty ambitious project, so please feel free to give any guidance you'd like - even if it's along the lines of telling me I'm crazy. :smile:


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## firemedic (Dec 26, 2010)

The slab your reffering to... Is it an cross/end cut? ie... Cut the end off a stump?


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## Road Explorer (Feb 24, 2011)

Thats correct. The slab is a crosscut section of a reclaimed elm tree.

Edit:
This is a picture of one of the slabs cut from this tree and looks almost identical to mine.


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## mdntrdr (Dec 22, 2009)

Road Explorer said:


> Thats correct. The slab is a crosscut section of a reclaimed elm tree.


 
That is refered to as a "cookie" not a slab.

A dutchman joint (bowtie) would be my prefference.

Then fill the crack with epoxy.

Others will chime in I'm sure. :smile:


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## Road Explorer (Feb 24, 2011)

Thanks for pointing out the cookie vs. slab thing. I'm hoping to do alot of these in the future, so knowing the technical term will be useful.

As for the dutchman joint, other than asthetics, I'm assuming I'll want to use as stable of a piece of hardwood I can find?


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## mdntrdr (Dec 22, 2009)

Road Explorer said:


> As for the dutchman joint, other than asthetics, I'm assuming I'll want to use as stable of a piece of hardwood I can find?


 
Any hardwood will work.

The thickness of cookie would be my deciding factor on dutchman thickness.

At 3" thick I would proly do 3/4" thick tie on both sides. :smile:


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## Road Explorer (Feb 24, 2011)

Excellent. Thanks for the pointers!


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## mdntrdr (Dec 22, 2009)

Make sure you orient the grain correctly on your Dutchman. :smile:


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## Road Explorer (Feb 24, 2011)

Will do. Not having made one before, I'll be doing some research on it.


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## mdntrdr (Dec 22, 2009)

Search Dutchman here, there are several threads with pics. :smile:


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## Locodcdude (Oct 24, 2010)

Yea just epoxy the crack considering it would be painted.


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## Road Explorer (Feb 24, 2011)

Mixing fine sawdust into the glue seems to be the way to go if I close up the cracks in addition to inserting a dutchman joint. I'm sure some of you have already seen this, but I ran across this video while searching for a dutchman joint:






Going to try that technique out on some throwaway stock as it seems like it'll do the trick.


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## firemedic (Dec 26, 2010)

I like good ole' epoxy myself. Your bigger issue though is going to be sealing the pores of the wood, IMO. Cross cut sections of wood like this can be tricky because there's really no stability to them. Wood's strength is oriented to the dirrection of grain. You never see cracks running sideways on a tree trunk  ie no amount of filler will prevent a crack. On the flip side though if the wood is dry and sealed that should helpbtobreduce the risk of further cracking. 

Someone mentioned it will be painted? The entire piece?

~tom


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## FiveOneSix (Sep 26, 2009)

*not for a penguin...*

couldnt you cut a bowtie from 8/4 stock and just resaw them so all the bowties in the piece would be the same? as per that video where they were all different.

makes sense to me! :yes:


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## Daren (Oct 14, 2006)

Road Explorer said:


> The slab... is *fairly* dry.


Of everything that was typed here...that concerns me. Does fairly dry mean kinda wet :huh: Do you know when it was cut/it's moisture content ? If it is still drying, well, I would let it do that before I ever messed with it.



.


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## Road Explorer (Feb 24, 2011)

The intent will be to route out a relief around raised lettering and chisel out a basic outdoor scene (trees...a fish...not sure yet) near the center. The relief area won't be painted, though I fully plan to stain/oil/whatever finish the entire piece to weatherproof it as best I can.

Thanks for the tip on sealing the pores. I originally posted here in the finishing forum to find out how to fill the cracks so that the weather here won't make them worse. I'm hoping that the advise on the finish will help prevent other cracks from forming. Sealing the pores seems like a good idea, but I've read a couple of dozen ways to do it and I'm a bit lost as to which method to use.

As for the "fairly dry" bit, I'm told it's been it's been drying for over a year, but I don't have a moisture content meter. I do intend to take a measurement before I start cutting into it.

Sorry if I have so many questions. I don't know anyone who does woodworking - even as a hobby. I'm asking all of these questions so as to learn from those of you who've been down this road and not make a "dumb rookie" mistake before I really tear into it.

I basically saw the piece advertised for sale and it sparked an idea. Given the rarity of finding something this size and shape around here, I jumped on it. I don't intend to even draw the lettering on it before I know exactly what I'm getting into regarding the cracks, weather protection, etc. :smile:


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## firemedic (Dec 26, 2010)

Road Explorer said:


> The intent will be to route out a relief around raised lettering and chisel out a basic outdoor scene (trees...a fish...not sure yet) near the center. The relief area won't be painted, though I fully plan to stain/oil/whatever finish the entire piece to weatherproof it as best I can.
> 
> Thanks for the tip on sealing the pores. I originally posted here in the finishing forum to find out how to fill the cracks so that the weather here won't make them worse. I'm hoping that the advise on the finish will help prevent other cracks from forming. Sealing the pores seems like a good idea, but I've read a couple of dozen ways to do it and I'm a bit lost as to which method to use.
> 
> ...


A couple coats of calbots sanding sealer before and after you start carving on it should do ya... The bow-ties may add a little challange for your carving skills, never been much of a carver myself though. 

Oh, and if your leaving the bark on, you need to get a suggestion from some one here about sealing that too...

If no one will see the back you could always cut a couple 1"x2" dados in the back adjacent to the majority of cracks and run hard wood splines... Just a thought... Anyone elses thoughts on that?

~tom


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## Road Explorer (Feb 24, 2011)

firemedic said:


> Oh, and if your leaving the bark on, you need to get a suggestion from some one here about sealing that too...
> 
> ~tom


The bark has was stripped off of the log prior to it being sliced up, so I should only have to worry about sealing the small (less than pea-sized) divets that are on the edge. I'm assuming - perhaps incorrectly - that the finished used for the face and back would also protect the sides in that case. Thoughts?


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## firemedic (Dec 26, 2010)

Road Explorer said:


> The bark has was stripped off of the log prior to it being sliced up, so I should only have to worry about sealing the small (less than pea-sized) divets that are on the edge. I'm assuming - perhaps incorrectly - that the finished used for the face and back would also protect the sides in that case. Thoughts?


The same sand N sealer will be just as fine for the sides too if no bark... I've never sealed anything bark before so I was unsure on that part...

~tom


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## Road Explorer (Feb 24, 2011)

I forgot to say in response to the question about putting splines in the back of the piece, the back of the piece will not be carved out and will not be visible from the street. Therefore, I can put any kind of support back there as long as it can be made to look tasteful (my skills aside... :laughing.


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## firemedic (Dec 26, 2010)

Road Explorer said:


> I forgot to say in response to the question about putting splines in the back of the piece, the back of the piece will not be carved out and will not be visible from the street. Therefore, I can put any kind of support back there as long as it can be made to look tasteful (my skills aside... :laughing.


You could even get crazy with it... Build almost a latice or gride of interlocking tenons in the back side... But that's REALLY overkill...


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