# Joining Slabs..glue vs epoxy



## USMCSergeant (Aug 21, 2012)

I'm going to be starting a new live edge table soon, and I've been thinking about how to join the two slabs. Since large slabs 7' - 10' are difficult to get perfect glue joints on (from previous experience), and since wood glue isn't gap filling, I've been thinking more about using epoxy with a slow hardener. 

System three has a hardener that has an open time of around 45 minutes, if the temp is above 75 degrees. That seems plenty long enough for gluing and clamping. It seems there is no downside here since epoxy is very strong and gap filling for any imperfect joint areas? I've found the resin / hardener with pumps, and thickener for a decent price at woodcraft.

Any opinions or experience to validate this?


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## Oneal-Woodworking (Apr 14, 2013)

USMCSergeant said:


> I'm going to be starting a new live edge table soon, and I've been thinking about how to join the two slabs. Since large slabs 7' - 10' are difficult to get perfect glue joints on (from previous experience), and since wood glue isn't gap filling, I've been thinking more about using epoxy with a slow hardener.
> 
> System three has a hardener that has an open time of around 45 minutes, if the temp is above 75 degrees. That seems plenty long enough for gluing and clamping. It seems there is no downside here since epoxy is very strong and gap filling for any imperfect joint areas? I've found the resin / hardener with pumps, and thickener for a decent price at woodcraft.
> 
> Any opinions or experience to validate this?


 
Depends on the slabs and how the wood wants to 'move' over time...

You could very well use epoxy based junk on a minor crack now and then 3 months from now have the table rip apart at the joint due to stresses in the wood that you could not predict or control with the epoxy...

Remind me to post pictures of our 'live edge' conference table at work that recently took a MAJOR crap and split (even though they used epoxy to fill cracks/seams). Conference table looks like CRAP now and I get to be the lucky 'fool' that gets to 'fix' it... :blink:

When I do eventually squeeze that junk back together there will be plently of steel involved and the wood will NOT be able to move again... Steel will NOT be seen if done correctly. No different than the truss rod on a guitar neck just on a larger scale... You use the steel to 'control' the movement of the wood over time.


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## USMCSergeant (Aug 21, 2012)

Good points. My first table was maple burl, and that SOB constantly moves. I think now, with huge slots in the base it moves back and forth monthly it seems and all is well so far. Sometimes I wonder how people keep slabs together at all!


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## Oneal-Woodworking (Apr 14, 2013)

USMCSergeant said:


> Good points. My first table was maple burl, and that SOB constantly moves. I think now, with huge slots in the base it moves back and forth monthly it seems and all is well so far. Sometimes I wonder how people keep slabs together at all!


You can use the steel 'tight joints' in the bottom (like people use on countertops) but those look like crap on a fine piece of woodworking in MY opinion. (ought not to see that junk on 'fine' woodworking in MY opinion) The 'bottom' ought to be clean also (in my view) on a piece of 'fine' construction... 

You can use 'dogbones' or other sorts of wood inlay fasteners on the top surface if you wish to prevent movement but that also distracts from the natural 'look'. (my builder digs those things - I hate them although they work to a certain extent)

Lag type bolts joining the slabs can easily be hidden and will NOT allow much (if any) movement. :yes:

I hate using anything but 'wood' on projects that I consider 'fine woodworking' but sometimes you 'need' the extra strength to keep things solid. I am NOT a big fan of nails and such...

When you 'must' use metal for joinery - I believe it is best to hide it...


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## woodnthings (Jan 24, 2009)

*the wood's gonna move*

A mechanical means like suggested above will help. Boring a long hole through each slab's edge and inserting a threaded rod will work. Otherwise the holes in each individual slab must be perfectly aligned to get a straight through hole.... not gonna be easy.

However, you can get a cleaner edge by butting the slabs together clamping them, and running a circ saw down the gap. Each pass will get you progressively closer to a "no gap" condition. Depending on the slab thickness, a 7 1/4" saw will do for most.

I don't like the dogbones either as they usually standout in an otherwise pure grain wood and detract from it. I'm with Oneal on the use of metal fasteners....don't use 'em unless no other means will work. :thumbsup:

A friend makes laminated raised panel doors with 1/4" skins of different woods. He uses the West system epoxy exclusively and swears by it. He's only gluing 1" X 3" pieces to form stiles and rails, so there is more uniformity of wood movement, than over a 8" wide single piece.


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## cabinetman (Jul 5, 2007)

woodnthings said:


> However, you can get a cleaner edge by butting the slabs together clamping them, and running a circ saw down the gap. Each pass will get you progressively closer to a "no gap" condition. Depending on the slab thickness, a 7 1/4" saw will do for most.


If the sections are clamped as you state, and then a saw is passed on the joint, the slabs will move after the cut, leaving a mismatch. The way I do that is separate the slabs just enough so a straight faced router bit can make a single pass and only skim off a small amount...like 1/16" from both pieces. A straightedge is used for the router base. For whatever deviations happen on one side, will read to the other, and you get a fitted jointed edge. Both slabs should be marked initially for where they line up on each other. This works if the router bit flutes are longer than the thickness of the slabs. Some "mills" as in end mills, have cutting edges on their length that will work as a router bit with a ½" shank.

I would use TB II or III, and clamps for a glue up. A blind spline can also be machined.










 







.


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## Gene Howe (Feb 28, 2009)

West Systems makes some great products. I use the 105 resin and the 205 hardener, but the 206 is slower. 
I would not use it, or any other epoxy, for your application. 
C-man posted the best solution for aligning the edges and suggested the correct adhesive choices. 
As long as the slab is dry before you work it, there shouldn't be any concern with movement if it is not constrained. That is not to say it won't move. It will.
If you are using the slab as a table of sorts with supports or aprons, just insure that the fasteners are free to move along the direction of any anticipated movement.


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## Oneal-Woodworking (Apr 14, 2013)

cabinetman said:


> If the sections are clamped as you state, and then a saw is passed on the joint, the slabs will move after the cut, leaving a mismatch.
> 
> 
> .


I think he meant clamp them down to the actual workbench.

His idea would work fine in my opinion.


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## woodnthings (Jan 24, 2009)

*You got it!*

Whether you cut down the gap with a router bit or a saw blade the results will be similar. You may take longer to set up the router than the circ saws, but saw... unclamp....move together a few times and you will be done and on your way....NOT if you have a skid of boards to do though. :no:

I keep a 8 1/4" Skil on hand for the heavy work like that. I think it weighs about 12 lbs. :blink: It's the first cir saw I bought when I was 13 yrs old....if it was big, I wanted it. :laughing:


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## USMCSergeant (Aug 21, 2012)

Great advice guys! No go on epoxy and stick with titebond 3. I think on this next slab I'll use blind splines, dutchmans on top, and be sure the base and legs allow movement across the grain. I may also place dutchmans on the bottom near the ends and one centered as well to help keep things tight over time. The burl live edge table has me nervous about movement. It's split twice at the ends, and I'm positive this slab was dry when I started it. I've fixed it since, but I don't want that problem to come back. 

Thanks again everyone.


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## Oneal-Woodworking (Apr 14, 2013)

USMCSergeant said:


> Thanks again everyone.


 
Thanks to YOU for your service USMCSergeant...

My dad was in USMC for over 20 years... Appreciate all that you guys do for our country and our freedoms. :thumbsup:


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## USMCSergeant (Aug 21, 2012)

You are welcome. I wish I could've served longer.


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## Oneal-Woodworking (Apr 14, 2013)

USMCSergeant said:


> You are welcome. I wish I could've served longer.


 
You got to be CRAZY to wish for that dude! :blink:

'Most' people have NO IDEA how hard the Marines WORK to protect our country and 'do what they do' day in and day out. There would be a heck of a LOT more respect for you guys if they DID know...

As a kid growing up I can vividly recall dad and his 'running' that he did to stay in shape for his 'duties' as a Marine. He would leave the house to go for his run and had mom come 'meet' him at a predetermined spot after a certain length of time (usually a few hours). Mom would then 'follow' dad in the car until he literally fell the hell out and could run NO LONGER and then cart his ass back to the house in the car... The guy would literally run until his body gave out MULTIPLE times each week to stay 'in shape' for the Marines... :blink:

Mom would also 'occasionally' get calls to bring the guys 'antifreeze' during their cold weather training. No doubt you KNOW what this sort of 'training' consisted of... 'Antifreeze' was the 'code word' for 'bring us some BEER'! LOL! :smile: Guys were still more or less 'locked up' and freezing their asses off while everyone else was basking in the summer heat... :blink:

My dad retired as a MSGT and I got some pics of him someplace serving with the presidential helicopter detail... There was NO helicopter in service that he could not 'fix' or maintain at that time...



Guys like you EARNED the respect that you deserve... :thumbsup:


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## USMCSergeant (Aug 21, 2012)

Ah well my service was cut short, I did almost 6 years, and I honestly enjoyed it. I've felt out of place ever since. It's been 8 years since I left. I don't think I'll ever find another job that I will be as proud, or where I feel I fit perfectly, but such is life.

Ok back on topic. I did find a great used jointer today. Ridgid 6" with extra set of knives for 240. Needs some cleaning, but other than that it's pristine.


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## USMCSergeant (Aug 21, 2012)

To avoid the inevitable pics or it never happened...


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## hays0369 (May 3, 2011)

Sweet deal on the Ridgid. Good luck on your new build I will be watching this one as well.

Semper Fi
Hays


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## BZawat (Sep 21, 2012)

USMCSergeant said:


> To avoid the inevitable pics or it never happened...


Nice. I have that exact model, bought it used on CL for 200 bucks. It's a great jointer. I've flattened boards 12' long on it using roller stands for infeed/outfeed extensions. 
You bought a good machine!

Brian


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## USMCSergeant (Aug 21, 2012)

BZawat said:


> Nice. I have that exact model, bought it used on CL for 200 bucks. It's a great jointer. I've flattened boards 12' long on it using roller stands for infeed/outfeed extensions.
> You bought a good machine!
> 
> Brian


Thanks Brian, it cleaned up nice


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## DonG1947 (Nov 14, 2012)

USMCSergeant said:


> Great advice guys! No go on epoxy and stick with titebond 3. I think on this next slab I'll use blind splines, dutchmans on top, and be sure the base and legs allow movement across the grain. I may also place dutchmans on the bottom near the ends and one centered as well to help keep things tight over time. The burl live edge table has me nervous about movement. It's split twice at the ends, and I'm positive this slab was dry when I started it. I've fixed it since, but I don't want that problem to come back.
> 
> Thanks again everyone.


 
I look forward to the day when I can contribute and not just ask questions! Can you explain "dutchman"? I assume you are not talking about putting an old drunken uncle under the table.

Don


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